DEVICE AND TEST MODULE FOR CONDUCTING FLUID MECHANICAL TESTS

Description

[0001] The invention relates to a device and at least one test module for carrying out fluid mechanics tests.

[0002] The device and the experimental module are used for technical training in the field of fluid mechanics, particularly at universities, technical colleges and technical schools.

[0003] The HM 150 series of devices from GUNT Gerätebau GmbH (GUNT Gerätebau GmbH: "Equipment for engineering education. Fluid mechanics", December 31, 2018 (2018-12-31), found online: URL: https: / / www.systemes-didactiques.fr / doc / catalogues / GU4-GUNT-GB.pdf) comprises a basic module for fluid mechanics experiments. It features a mobile, supporting frame with an upper work surface on which various experimental devices can be positioned. At the bottom of the frame is a large reservoir for test fluid with a capacity of approximately 180 l, which contains a submersible pump. The submersible pump is connected via a ball valve to an inlet in the bottom of a test flume in the work surface. The test flume can be used for conducting experiments at the weir. A measuring container that collects the test fluid is connected to the test flume.The test fluid flows back into the storage tank via a drain in the bottom of the measuring tank. For other experiments, a variety of test devices are available, each with individual frames, supports, or plates that allow them to be positioned on the work surface of the base module. A hose connects the submersible pump to a test device placed on the work surface. The test fluid flows into the measuring tank from an overflow or other outlet on the test device. The flow rate is adjusted using the ball valve. To determine the flow rate, a level indicator is connected to the measuring tank, and its drain can be closed using a slide valve. After closing the slide valve, the fill level is measured within a time period determined by a stopwatch, and the flow rate is determined from this.Some experimental devices are equipped with analog pressure gauges that must be read during the experiments. The results must be recorded on paper. Details on the operation of the device series and the test procedure can be found in the written instructions for use.

[0004] The test procedure, especially the flow measurement, is time-consuming and inaccurate. The pump always runs at full power, resulting in high energy consumption, and throttling the flow rate using the ball valve causes the test fluid to heat up accordingly. This change in the test conditions complicates the test procedure and affects the measurement results. The test fluid can easily become contaminated in the open system. The base module and the test equipment require a lot of space.

[0005] The HM 150.21 experimental module for visualizing flow lines in an open channel has an open frame at the bottom for mounting on the tray insert of the HM 150 experimental device. Water flows from an open experimental channel over a weir and falls through an area not covered by the open frame of the experimental module into an opening in the measuring tank of the HM 150 experimental device.

[0006] DE 20 2015 106 972 U1 describes a test device for investigating flow fields. It has a vertical flow channel with a transparent front panel on a mobile frame, integrated into a circulation line in which a pump for circulating test fluid is arranged. At least one test body is located in the flow channel. Using a linear electrode below the test body and another electrode in the flow channel with a connected electrical power supply, gas bubbles are electrolytically generated in the test fluid. These bubbles follow the flow of the test fluid. The test device requires a large amount of space and is specialized for investigating flow fields.

[0007] US Pat. No. 5,324,956 describes a system for characterizing the pressure, temperature, movement, and flow patterns of a fluid under high pressure within a test cell. The test cell is internally lined with adjustable rock surfaces. The pressure is measured within the test cell using a device that utilizes compression-deformable optical fibers. Fluid velocity, flow direction, and filter cake structure are measured using laser Doppler velocimetry. The fluid temperature is estimated using a combination of thermal sensors.

[0008] Based on this, the invention is based on the object of providing a device and at least one test module for carrying out fluid mechanics tests, which enable a faster and more accurate execution of a large number of different fluid mechanics tests.

[0009] The object is achieved by a device having the features of claim 1. Advantageous embodiments of the device are specified in subclaims.

[0010] The device according to the invention for carrying out fluid mechanics tests comprises: a table housing with a horizontal upper housing wall with a support surface on the top and a first opening formed therein for mounting a test module with a base plate and a test arrangement for fluid mechanics tests arranged thereon, an externally accessible first connection for a hose on a housing wall, so that the first connection can be connected by means of a first hose to a second connection of the test module for feeding test fluid into the test arrangement when the test module is placed on the support surface, a trough-shaped storage container for test fluid arranged in the table housing, which is directly accessible from above through the first opening in the support surface, so that test fluid can be discharged from the test arrangement into the storage container through an outlet of the test arrangement on the underside of the base plate,when the test module is placed on the support surface, a first pump arranged in the table housing, which is connected on the inlet side to the interior of the storage container and on the outlet side to the first connection, an electric motor arranged in the table housing and coupled to the first pump, and an electrical control device arranged in the table housing and connected to the electric motor, which is designed to adjust the speed of the first pump.

[0011] Furthermore, the object is achieved by a test module according to claim 21. Advantageous embodiments of the test module are specified in subclaims.

[0012] The test module according to the invention for carrying out fluid mechanics tests comprises a base plate for placing on a support surface and covering a first opening formed therein to a storage container of a test device, a test arrangement for fluid mechanics tests arranged on the base plate, a second connection for feeding test liquid into the test arrangement by means of a first hose and a first outlet for test liquid on the underside of the base plate, which is connected to the test arrangement via a device for conducting test liquid and / or a second outlet for test liquid above the base plate for connection to a drain line.

[0013] In the device according to the invention for conducting fluid mechanics experiments (also called "device" or "basic device" or "basic unit" or "main unit"), the first opening of the trough-shaped reservoir is accessible directly from above through the support surface. The test module according to the invention (also called "module") is placed on the support surface with its base plate so that it covers the first opening of the reservoir and discharges the test fluid directly into the reservoir through the first outlet on the underside of the base plate. As a result, only relatively small quantities of test fluid are required. The base plate prevents splashing of test fluid and the penetration of contaminants into the test fluid. The test fluid is pumped through the test setup by the pump located in the table housing of the device.For this purpose, the first connection of the device can be connected to the second connection of the test module via a hose. The speed of the first pump can be adjusted via an electrical control device and an electric motor of the device without the test fluid being heated by throttling. The small total quantity of test fluid and the lack of heating due to throttling of the flow rate enable fluid mechanics experiments to be carried out faster and more accurately. In particular, constant flow conditions in the test setup can be achieved quickly. Alternatively, the test fluid can be drained off via the second outlet through a drain line (e.g. a sewer line), especially if it is provided with a marking fluid (e.g. ink) as it flows through the test setup and this marking fluid is not to be enriched in the reservoir.Water, e.g. drinking water from the mains network, can be used as the test liquid.

[0014] According to one embodiment of the device, an inner step, offset downwards relative to the base surface, runs around the inner edge of the opening to support the outer edge of the base plate. This facilitates precise positioning of the test module on the device.

[0015] According to a further embodiment, at least one layer of open-pore foam is arranged in the interior of the storage tank. This prevents sloshing of the tank contents and splashback of liquid discharged from the first outlet, thus promoting rapid and accurate testing.

[0016] According to a further embodiment, a first layer of a first open-pore foam is arranged in the interior, followed by a second layer of a second open-pore foam. The second layer is thinner than the first layer and the second open-pore foam has finer pores than the first open-pore foam. This particularly effectively prevents sloshing of the test liquid in the reservoir and splashback of the test liquid.

[0017] According to a further embodiment, a volume flow sensor, preferably a magnetic inductive sensor, is arranged in a first line between the first pump and the first connection to measure the volume flow of the test fluid. This allows the volume flow to be measured quickly and accurately. According to another embodiment, the volume flow is determined via the pump speed. This is particularly possible with knowledge of the pump characteristic curve and the characteristic curve of the test setup of the test module used.

[0018] According to a further embodiment, a first reference pressure connection and at least one first pressure connection are arranged on a housing wall of the table housing and are accessible from the outside, and at least one pressure sensor for measuring a differential pressure is arranged in the table housing and is connected to the first reference pressure connection and the first pressure connection, so that the first reference pressure connection can be connected to a second reference pressure connection of a test arrangement via a second hose and the first pressure connection can be connected to a second pressure connection of the test arrangement via a third hose when the test module is placed on the support surface. This enables the conduct of fluid mechanics experiments that require pressure measurements. The separate equipment of the test modules with pressure measuring devices can be omitted.The device can be equipped with a particularly accurate pressure sensor and the measured pressures can be displayed on the device in a particularly perceptible manner.

[0019] According to another embodiment, the pressure sensor is connected to various first pressure ports via solenoid valves. This makes it possible to measure pressures at various points in a test setup on a test module.

[0020] According to another embodiment, the device comprises several parallel-connected pressure sensors with different measuring ranges. This allows pressures to be measured over a very wide overall measuring range.

[0021] According to another embodiment, a temperature sensor is arranged in the bench housing, which engages in the first line between the pump and the first connection or in the interior of the reservoir to measure the temperature of the test fluid. This allows the influence of temperature on fluid mechanics experiments to be investigated.

[0022] According to a further embodiment, a heating device and / or a cooling device is arranged in the table housing, which is integrated into a circulation line with a second pump arranged therein and / or into the storage container to heat and / or cool the test liquid. This enables compliance with specified test temperatures.

[0023] According to a further embodiment, the heating device is an electric resistance heater and / or the cooling device is a heat exchanger connected to coolant connections arranged on a housing wall, which is accessible from the outside for connecting it to a chiller or another coolant source by means of a fourth and a fifth hose. Tap water can be used as the coolant if necessary.

[0024] A further embodiment comprises a device for venting the devices for measuring the differential pressure, which comprises the circulation line and the second pump arranged therein, as well as solenoid valves, by means of which the test fluid can be pumped either through a second line between the pressure sensor and the first reference pressure connection and a second hose connected thereto, as well as the test arrangement of a test module placed on the support surface connected thereto via the second reference pressure connection, and from there back into the test container, or through a third line between the pressure sensor and the first pressure connection and a third hose connected thereto, as well as the test arrangement connected thereto via the second pressure connection, and back into the storage container. By switching the solenoid valves, all lines of the pressure measuring system can be vented.Venting can be performed automatically if necessary, facilitating rapid and accurate testing.

[0025] According to a further embodiment, the first pump is a centrifugal pump and / or the first pump is a submersible pump and / or the second pump is a centrifugal pump and / or the second pump is a submersible pump. The use of centrifugal pumps is particularly advantageous due to their simple, space-saving, and robust design.

[0026] According to a further embodiment, the device comprises a computer and a connected, externally accessible touch panel (also called a "touchscreen") arranged in a wall of the table housing. The computer is configured to display information about the device and / or the experimental module and / or the learning content and / or the experimental setup and / or the experimental procedure and / or measurement results and / or evaluations of measurement results on the touch panel and / or, depending on inputs via the touch panel, to control the venting of the devices for measuring the differential pressure and / or the execution of experiments and / or the recording of measurement results and / or the evaluation of measurement results. This promotes rapid and accurate experimental execution and a particularly instructive communication of the learning content.

[0027] According to another embodiment, the computer is internet-capable and / or includes a WLAN access point networked with the computer. This enables the aforementioned information to be distributed and the device to be controlled via the internet.

[0028] According to a further embodiment, the device comprises an RFID reader connected to the computer, which is configured to read an identifier stored on an RFID of a test module when the module is placed on the support surface. The computer is configured to control the program sequence depending on the identifier read by the RFID. This facilitates particularly fast and precise test execution.

[0029] According to a further embodiment, the table housing has at least one first measurement signal connection on a housing wall, which is connected to the computer, accessible from the outside, and connectable via a first electrical cable and a second electrical measurement signal connection to an electrical measuring sensor on a test module when the module is placed on the support surface. This enables the acquisition of signals from electrical measuring sensors on the test modules. This facilitates the conduct of further experiments and ensures fast and accurate test execution.

[0030] The device comprises a table housing, wherein the components of the device are arranged entirely or substantially in and / or on the table housing. The table housing is a housing that can be placed on a table, in particular on a desk in a classroom or lecture hall. The device can be designed in a particularly compact, portable housing. According to one embodiment, the table housing has a base area of ​​a maximum of 0.75 meters x 1 meter and a maximum height of 0.9 meters. The table housing preferably has a base area of ​​0.575 meters x 0.73 meters and a height of 0.685 meters. According to one embodiment, the device has a maximum weight of 50 kg, preferably a maximum of 40 kg. As a result, the device has a small footprint and can be carried by one or more people.

[0031] According to a further embodiment, the table housing comprises a lower part with the support surface on a top side and a control cabinet projecting upwards at the rear edge of the lower part. The reservoir, the first pump, and optionally the second pump are located in the lower part, while the control device, the measuring sensors, the computer, and the touch panel are located in the control cabinet. This allows for an advantageous division and separation of hydraulic and electrical components.

[0032] Furthermore, the arrangement of the touch panel and, if applicable, switching devices in the control cabinet is particularly advantageous for operation and the recording of information.

[0033] According to a further embodiment, the first connection and, if applicable, the first reference pressure connection and the first pressure connection and, if applicable, a first electrical measurement signal connection for an external electrical sensor and, if applicable, first electrical power connections for an external load and, if applicable, the touch panel are arranged in a front housing wall of the control cabinet facing the installation surface. This is advantageous for the separation of hydraulic and electrical components and for the operation of the device.

[0034] According to another embodiment, the table housing includes handles for carrying the table housing. This is advantageous for setting up and dismantling the test equipment.

[0035] According to one embodiment of the test module, the test setup is pumpless. A pumpless test setup is one that does not have its own pump to pump the test fluid through the test setup. In this embodiment, the test fluid is pumped exclusively by the device's first pump.

[0036] According to one embodiment, the test module comprises a second reference pressure connection and at least one second pressure connection connected to the test setup, and / or at least one second measurement signal connection connected to an electrical sensor in the test setup, and / or second electrical power connections for connection to an electrical voltage source, which are connected to an electrical load on the base plate. The load is, for example, an electrode arrangement for generating gas bubbles and / or a lamp for illuminating a flow field.

[0037] According to one embodiment, the test module comprises an RFID on which a readable identifier with an identification of the test module is stored.

[0038] According to one embodiment, the experimental module includes handles for carrying the experimental module. According to another embodiment, the carrying handles protrude upward from the base plate. This is advantageous for setting up and dismantling the experimental equipment.

[0039] The test module for conducting fluid mechanics tests includes one of the following test setups: a pipe made of a transparent material held on the base plate, a device for feeding a marking liquid between a first pipe end of the pipe and the second connection, a container for marking liquid held above the feeding device, a metering valve arranged in a feed line between the container and the feeding device, a pipe bend made of a transparent material connected to a second pipe end of the pipe and having a second outlet at the other end for connection to a drain line or for connection to an outlet line to a first outlet in a bore in the base plate; at least one horizontal pipe held on the base plate, which is connected at a first pipe end to the second connection via a nozzle or a sharp-edged inlet and whose second pipe end is connected to the first outlet via a collecting container for test liquid,wherein, in the collecting container, a cannula engaging in the tube is displaceable transversely to the tube cross-section by means of a displacement device, and the cannula is connected to a second pressure connection; a vertical flow channel, held on the base plate, with a transparent front plate, which is connected at the bottom to the second connection and at the top via at least one outlet line to the first outlet, in which at least one test body is arranged or can be arranged, in which a first electrode, at least partially spanning the cross-section of the flow channel, and in which a second electrode are arranged below the test body, wherein the first electrode and the second electrode are connected to second electrical power connections for connecting an electrical voltage source; a tube made of a transparent material, held on the base plate, which has the second connection at a first tube end,adjacent thereto a first pipe section with a larger diameter, adjacent thereto a conical or otherwise tapered transition section and adjacent thereto a second pipe section with a smaller diameter and is connected at the other end to the first outlet via an outlet line, wherein a first impeller is arranged in the first pipe section and a second impeller is arranged in the second pipe section, next to the first pipe section a first sensing device for sensing the rotational speed of the first impeller, next to the second pipe section a second sensing device for sensing the rotational speed of the second impeller is arranged and the first and second sensing devices are connected to second measuring signal connections; a mounted on the edge of the first outlet designed as a second opening in the base plate,A transparent collecting cylinder with a vertical axis, closed at the top, a nozzle connected to the second connection and directed vertically upwards above the first opening in the collecting cylinder, a baffle element held vertically above the nozzle on an arm of a lever pivotably mounted on a support, a force measuring device supported on one side by an abutment and on the other side by the other arm of the lever, the inlet of the nozzle being connected to the second pressure connection and the force measuring device being connected to the second measurement signal connection; a transparent cylinder arranged on the base plate with a vertical axis, with the second connection at the lower end and an outlet opening arranged above it on the side, to which various interchangeable opening elements can be attached, a shaft arranged laterally next to the cylinder and open towards the outlet opening, open at the top and with at least one transparent front wall,which is open at the bottom towards the first outlet formed as a second opening in the base plate, wherein the shaft is open at the top above the outlet opening and a length measuring device is provided on the upper edge of the shaft, which can be positioned at various distances from the outlet opening to measure the distance of a test liquid jet emerging from the outlet opening from the upper edge of the shaft, wherein the second pressure connection is arranged at the bottom of the cylinder and the second reference pressure connection is arranged at a basin on the base plate; a horizontal Venturi nozzle made of a transparent material, held above the base plate, which is connected at one end to the second connection and at the other end via an outlet line to the first outlet of the base plate, wherein pressure measuring holes are provided at various points on the nozzle and diffuser of the Venturi nozzle,which are connected to second pressure and second reference pressure connections protruding from the outside of the Venturi nozzle, wherein from the other end, a pressure lance can be inserted into the Venturi nozzle through a seal and positioned with the inlet opening at various axial positions in the Venturi nozzle, and the pressure lance is connected at the other end to a second pressure connection; several horizontal, equally long tubes with various internals, which are held parallel to one another on the base plate, which are preferably selected from a tube with a large inner diameter and a built-in nozzle, a tube with a large inner diameter and a built-in orifice, a tube with a small inner diameter and a built-in nozzle, a tube with a small inner diameter, an S-bend and a built-in nozzle, a tube with a small inner diameter, a sharp-edged S-bend and a built-in nozzle, and a tube with a small inner diameter,Double S-bend and built-in nozzle and a pipe with a small inner diameter, built-in valve and built-in nozzle, wherein the small inner diameter is a smaller inner diameter than the large inner diameter, wherein the pipes are connected at first pipe ends to a distribution block having the second connection and a second pressure connection, and the pipes are connected at second pipe ends via hand valves to a drain block having a second reference pressure connection and connected via an outlet line to the first outlet in the base plate; horizontal pipes and pipe bundles with different inner diameters held side by side on the base plate, each having the second connection at the first pipe ends and whose second pipe ends each open above a second opening in the base plate extending transversely to the pipes and forming the outlet,which is enclosed at the edge remote from the pipes and pipe bundles and at edges parallel to the pipes and pipe bundles by splash guards projecting up from the base plate, wherein the pipes and pipe bundles each have a second pressure connection and a first vent valve at a distance from the second connection and a second reference pressure connection and a second vent valve at a further distance from the second connection, and optionally a pipe bundle has a second pressure connection and a third vent valve at a distance from the second connection that is closer to the second connection; horizontal pipes held next to one another on the base plate, comprising a hydraulically smooth pipe, a hydraulically rough pipe, and a rectangular pipe, each having a second connection at first pipe ends,at a distance therefrom, a second pressure connection and at a further distance therefrom, a second reference pressure connection, and a pipe with more than three pressure measuring bores along an inlet section, of which the two outer ones are connected to a second reference pressure connection and the others are each connected to a second pressure connection, wherein all pipes have a second connection at the first pipe end and only the pipe with more than three pressure measuring bores also has a second connection at the second pipe end, and the second pipe ends of all pipes open into a second opening in the base plate extending transversely to the pipes and forming the first outlet, which opening is enclosed at the edge remote from the pipes and at side edges parallel to the pipes by splash guard walls projecting up from the base plate; a horizontal flow channel on the base plate with at least one front wall made of a transparent material,a second connection at one end of the flow channel and a connection to the first outlet at the other end of the flow channel, several internal components that can be inserted into the flow channel and fixed therein by means of magnets for demonstrating energy levels and losses as well as for determining flow rates when flowing through the flow channel.

[0040] Furthermore, the invention comprises a system for carrying out fluid mechanics tests comprising a device according to one of claims 1 to 20 and at least one test module for carrying out fluid mechanics tests comprising a base plate for placing on a support surface and covering a first opening formed therein to a storage container of a device according to claim 1, a test arrangement for fluid mechanics tests arranged on the base plate, a second connection for feeding test liquid into the test arrangement by means of a first hose, a first outlet for test liquid on the underside of the base plate, which is connected to the test arrangement via a device for conducting test liquid, and / or a second outlet for test liquid above the base plate for connection to a drain line.

[0041] The device and the experimental module are collectively referred to as "experimental devices".

[0042] According to a further embodiment, the system comprises a mobile rack with several shelves for storing the device and several test modules.

[0043] The invention is explained in more detail below with reference to the accompanying drawings of exemplary embodiments. In the drawings: Fig. 1 shows a device for conducting fluid mechanics tests in a perspective view obliquely from the front and from the side; Fig. 2 shows the same device with the rear panel removed in a rear view; Fig. 3 shows the system of the device for measuring pressures in the test arrangements and for heating / cooling the test fluid in a hydraulic diagram; Fig. 4 shows a first test module for visualizing pipe flow in a perspective view obliquely from the front and from the side; Fig. 5 shows a second test module for measuring the flow profile in a perspective view obliquely from the front and from the side; Fig. 6 shows the same test module in a perspective view obliquely from the rear and from the side; Fig. 7 shows a third test module for visualizing streamlines in a perspective view obliquely from the front and from the side; Fig. 8 shows the same test module in a partial view from the rear; Fig.Fig. 9A fourth test module for investigating the continuity equation in a perspective view obliquely from the front and from the side; Fig. 10A fifth test module for measuring jet forces in a perspective view obliquely from the front and from the side; Fig. 11The same test module with the collecting cylinder removed in a perspective view obliquely from the back and from the side; Fig. 12A sixth test module for investigating free outflow in a perspective view obliquely from the front and from the side; Fig. 13The same test module in a perspective view obliquely from the back and from the side; Fig. 14A seventh test module for investigating Bernoulli's law in a perspective view obliquely from the front and from the side; Fig. 15An eighth test module for investigating losses in pipelines in a perspective view obliquely from the front and from the side; Fig.16A ninth test module for investigating the fundamentals of pipe friction in a perspective view obliquely from the front and from the side; Fig. 17A tenth test module for investigating the pressure profile along the inlet section in a perspective view obliquely from the front and from the side; Fig. 18An eleventh test module for investigating the flow in an open channel in a perspective view obliquely from the front and from the side; Fig. 19The same test module in a partial view from the back, Fig. 20A movable rack in a perspective view obliquely from the front and from the side, Fig. 21The system of... Fig. 3 in the pressure measurement; Fig. 22The same system when bleeding the pressure connections; Fig. 23The same system when bleeding the pressure sensors; Fig. 24The same system when heating / cooling the test fluid.

[0044] According to Fig. 1 and 2The device 1 comprises a table housing 2 with a flat, essentially cuboid-shaped lower part 3 and a flat, cuboid-shaped control cabinet 4 standing upright at the rear edge of the lower part 3. Overall, the table housing 2 is designed as a desk housing.

[0045] The lower part 3 has a horizontal upper housing wall 5 with a support surface 6 and a substantially rectangular first opening 7 formed therein. On the inner edge of the first opening 7 there runs an inner step 8 which is offset downwards with respect to the support surface 6.

[0046] Pivoting handles 9 for carrying the table housing 2 are arranged on both sides of the lower part 3.

[0047] On a front housing wall 10 of the control cabinet 4, which is located on the side of the base 6 of the lower part 3, a first connection 11 is arranged, which is connected to the output of a first pump 12. The first connection 11 is designed as a hose coupling for connecting a hose.

[0048] On the Fig. 1 On the right side of the front housing wall 10 of the control cabinet 4, a total of seven first pressure connections 14.1 to 14.7 are arranged, and to the right of them, a first reference pressure connection 15. The pressure and reference pressure connections 14.1 to 14.7 and 15 are also designed as hose couplings.

[0049] Above this, a touch panel 16 is embedded in the front housing wall 10.

[0050] Next to the touch panel 16, a USB socket 17 is arranged in the front housing wall 10, into which a USB stick can be inserted to store measurement results.

[0051] The device 1 has a multi-pin socket 18 for connecting electrical measuring sensors and / or electrical loads on the front housing wall 10, in addition to the first pressure and reference pressure connections 14.1 to 14.7, 15. The socket 18 comprises first measurement signal connections 19 and first electrical power connections 20.

[0052] According to Fig. 2 An on / off switch 21 and coolant connections 22.1, 22.2, e.g., for cooling water, which are also designed as hose couplings, are located on the rear of the control cabinet 4. The on / off switch 21 and the coolant connections 22.1, 22.2 are held in a frame strip 23 of the control cabinet 4, to which a rear housing wall can be fixed.

[0053] According to Fig. 2 and 3A tub-shaped storage container 24, which is formed, for example, as a deep-drawn plastic mold, is arranged in the lower part 3. The storage container 24 has, for example, a volume of 10 liters. The storage container 24 is essentially filled with a first layer of a first open-pore foam 25. Above this is a thin second layer of a fine-pore foam 26.

[0054] The first pump 12, designed as a submersible pump, is arranged in the reservoir 24 in corresponding holes in the foam layers 25, 26. The first pump 12 is connected on the output side to the first connection 11 via a first line 27 to a volume flow sensor 28 arranged in the control cabinet 4, which is structurally combined with a temperature sensor 29.

[0055] Pressure sensors 30.1, 30.2, and 30.3 are arranged in parallel in the control cabinet 4. Pressure sensors 30.1, 30.2, and 30.3 are connected to the first reference pressure port 15 via a second line 31. Pressure sensors 30.1, 30.2, and 30.3 are connected to the first pressure ports 14.1 to 14.7 via a third line 32 containing solenoid valves 33.1 to 33.7, which are structurally combined in a first valve block 34.

[0056] A second pump 35, also designed as a submersible pump, is located in the reservoir 24 in corresponding holes in the foam layers 25, 26. The second pump 35 is connected to the reservoir 24 on the outlet side via a circulation line 36 containing a heating device 37 in the form of an electric resistance heater or a heat exchanger and a cooling device 38 in the form of a tubular cooler. The cooling device 38 is connected to the two coolant connections 22.1, 22.2.

[0057] The first pump 12 and the second pump 35 are each designed as centrifugal pumps and each comprise an electric motor for driving the centrifugal pump.

[0058] A first switching valve 39 is arranged in the circulation line 36 between the second pump 35 and the heating device 37. Between the first switching valve 39 and the second pump 35, the circulation line 36 is connected to the third line 32 via a first connecting line 40 between the pressure sensors 30.1, 30.2, 30.3 and the solenoid valves 33.1 to 33.7. A second switching valve 41 is arranged in the first connecting line 40. The inlet and outlet sides of the pressure sensors 30.1, 30.2, 30.3 are connected to one another via a second connecting line 42, in which a third switching valve 43 is arranged. The first, second, and third switching valves 39, 40, 43 are structurally combined in a second valve block 44.

[0059] A computer 45 is integrated into the touch panel 16. The computer 45 is connected to the first and second pumps 12, 35, the pressure sensors 30.1, 30.2, 30.3, the solenoid valves 33.1 to 33.7, the switching valves 39, 41, 43, the electric heater 37, the volume flow sensor 28, the temperature sensor 29, and the multi-pin socket 18.

[0060] Computer 45 is internet-capable and has a WLAN access point.

[0061] The computer 45 is also an electrical control device for the first pump 12 and the second pump 35. A power supply unit 46 is also located in the control cabinet 4.

[0062] Furthermore, the device 1 comprises a reader 47 for an RFID, which is arranged below the support surface 6 and is connected to the computer 45.

[0063] According to Fig. 4 to 19The test modules 48 each have a base plate 49 with identical dimensions, which can be precisely placed on the inner stage 8 of the basic device 1. Furthermore, each test module 48 comprises a second connection 50 for feeding test liquid and a first outlet 51 for test liquid on the underside of the base plate 49 and / or a second outlet 52 for test liquid above the base plate 49. A test arrangement is located between the second connection 50 and the first or second outlet 51, 52.

[0064] Second pressure and reference pressure connections 53, 54 and second measurement signal connections 55 for additional module-specific measurement technology may be provided depending on the tests to be conducted with the respective test module 48. An RFID 56 is integrated into the base plate 49, in which a readable identifier with an identification of the respective test module 48 is stored.

[0065] According to Fig. 4The first test module 48.1 comprises a horizontal tube 57 made of a transparent material and held on the base plate 49. Furthermore, a device 58 for feeding a marking liquid into the test liquid is provided between a first tube end 59 of the tube 57 and a second connection 50 in the form of a hose coupling for connection to the first connection 11. A container 60 for marking liquid is held in a height-adjustable manner on a rod 61 projecting vertically from the base plate 49. An opening at the lower end of the container 60 is connected to the feeding device 58 via a metering valve 61.1 and a feed line 62. A second tube end 63 of the tube 57 is connected via a pipe bend 64 made of a transparent material to a vertically upwardly projecting second outlet 52 above the base plate 49, via which outlet the tube 57 can be connected to a drain line. In the first test module 48.1, the base plate 49 has a first outlet 51 in the form of a bore 65 into which the end of a hose connected to the pipe bend 64 can be inserted in order to return the test liquid to the storage container 24.

[0066] According to Fig. 5 and 6 The second test module 48.2 comprises two horizontal tubes 57.1, 57.2 held on the base plate 49, which are connected at the first tube end 59 to the second connection 50 via a nozzle 66 or a sharp-edged inlet 67. The second tube end 63 is connected to the first outlet 51 via a collecting container 68 for test liquid.

[0067] In the collection container 68, a cannula 71 engaging in the tube can be displaced transversely to the tube cross-section by means of a displacement device 69 with a dial gauge 70. The cannula 71 is connected to a second pressure connection 53. The collection container 68 has a second reference pressure connection 54. The second pressure connection 53 is arranged on the top side of the collection container 68, and the second reference pressure connection 54 is arranged on its rear side. The dial gauge 70 determines the position of the cannula 71 in the tube cross-section, as adjusted by the displacement device 69.

[0068] On the rear side of the collection container 68, a polygonal socket 74.1 is located for connecting the dial gauge 70. This socket is wired to a round socket 74.2 located adjacent to it, forming the second measurement signal connection 55, at which the measurement signals of the dial gauge for the position of the cannula 71 are provided.

[0069] According to Fig. 7 and 8The third test module 48.3 has a vertical flow channel 76 mounted on the base plate 49 with a transparent front plate 77. The flow channel 76 is connected at the bottom to the second connection 50 and at the top via outlet lines 78.1, 78.2 through bores 65.1, 65.2 in the base plate 49 to the first outlet 51 on the underside of the base plate 49.

[0070] The flow channel 76 has guide rails 79.1, 79.2 on its side walls. Test specimens 80.1, 80.2 can be inserted into these. Below the test specimens 80.1, 80.2, a first electrode 81 spans at least partially the cross-section of the flow channel 76. The first electrode 81 is a wire held at the two lateral edges of the flow channel by electrically conductive pins 82.1, 82.2, which extend outward through an insulating rear wall 83. The flow channel 76 further comprises a second electrode 84. This is an electrically conductive strip, which is attached at the level of the first electrode 81 by means of electrically conductive screws 85.1, 85.2, which extend outward through the rear wall 81. The pins 82.1, 82.2 and the screws 85.1, 85.2 form second electrical power connections 86.1, 86.2 for connecting an electrical voltage source.

[0071] At the lower end of the flow channel 76, opposite the second connection 50, a drain valve 87 is arranged, which is aligned with a bore 65.3 of the base plate 49.

[0072] On one side, the flow channel 76 has a clamp holder 88, to which a cleaning slide 89 is held on a stem 90, which has a cleaning head 91 with a circumferential rubber lip 92 at the bottom and a handle 93 at the top. Bubbles can be removed from the walls of the vertical flow channel 76 by means of the cleaning slide 89.

[0073] According to Fig. 9The fourth test module 48.4 has a tube 57 made of a transparent material, held on the base plate 49. The tube 57 has the second connection 50 at the first tube end 59. Starting from the second connection 50, the tube widens to a cylindrical first tube section 94 with a larger cross-section. The first tube section 94 is followed by a conical transition section 95 and this is followed by a cylindrical second tube section 96 with a smaller diameter. This is followed by the second tube end 63 of the tube 57, which is connected via an outlet line 78 through a bore 65 in the base plate 49 to the first outlet 51 on the underside of the base plate 49.

[0074] A first impeller 97 is arranged in the first pipe section 94, and a second impeller 98 is arranged in the second pipe section 96. A first sensing device 99 for sensing the rotational speed of the first impeller 97 is arranged next to the first pipe section 94, and a second sensing device 100 for sensing the rotational speed of the second impeller 98 is arranged next to the second pipe section 96. The first and second sensing devices 99, 100 are connected to second measurement signal terminals 55.1, 55.2.

[0075] In another embodiment, the tube 57 is held in a vertical orientation on the base plate 49 to facilitate venting.

[0076] According to Fig. 10 and 11The fifth test module 48.5 has a top-closed and transparent collecting cylinder 102 with a vertical axis, placed on the edge of the first outlet 51, formed as a second opening 101 in the base plate 49. A replaceable nozzle 66 is connected to a second connection 50 and is directed vertically upward above the second opening 101 in the collecting cylinder 102. Above the nozzle 66, a replaceable impact element 106 is held in the collecting cylinder 102 on an arm 103.1 of a lever 105 pivotably mounted on a support 104. A force measuring device 107 is supported on the one hand on an abutment 108 on the support 104 and on the other hand on the other arm 103.2 of the lever 105. The inlet of the nozzle 66 is connected to the second pressure port 53 and a vertical tube 109 arranged in the collecting cylinder 102 with an orifice at the level of the orifice of the nozzle 66 is connected to the second reference pressure port 54.

[0077] A connector cable is routed from the force measuring device 107 to a connector through an internal cable bushing 74.3 adjacent to the nozzle 66 and cable bushings 74.4, 74.5 on the holder 112. Additional nozzles 66 and impact elements 106 are provided on a holder 112 on the base plate 49.

[0078] According to Fig. 12 and 13The sixth test module 48.6 comprises a transparent cylinder 115 arranged on the base plate 49 with a vertical axis, with the second connection 50 at the lower end. Above this, the cylinder 115 has an outflow opening 116 on the side, to which various interchangeable opening elements 117 can be attached. Arranged laterally next to the cylinder 115 is a shaft 118, open at the top and open toward the outflow opening 116, with a transparent front wall 119. The shaft 118 is open at the bottom to the first outlet 51, which is designed as a rectangular second opening 101 in the base plate 49. At the top, the shaft 118 is open above the outflow opening 116. On the upper edge of the shaft 118, a length measuring device 120 with a holder 121 is arranged, which can be inserted into various pairs of grooves 122 on the upper edge of the shaft 118.The length measuring device 120 serves to measure the distance of a test liquid emerging from the outflow opening 116 from the upper edge of the shaft 118 at various distances from the outflow opening 116.

[0079] A second pressure port 53 is located at the base of cylinder 115. A second reference pressure port 54 is located at a small basin 123, which is separate from cylinder 115 and located on the inside of shaft 118.

[0080] On the base plate 49 there is a holder 112 on which various opening elements 117 or nozzle inserts are mounted, which can be fastened to the outflow opening 116.

[0081] The signal is routed from the length measuring device 120 via a cable to a polygonal socket 74.6 on the top of the holder 112. This socket is wired within the holder 112 to a round socket 74.7, which also serves as the second measurement signal connection 55.

[0082] The sixth test module 48.6 has a drain valve 87 at the lower end of the cylinder 115, which is aligned with a bore 65 in the base plate 49.

[0083] According to Fig. 14The seventh test module 48.7 comprises a horizontal Venturi nozzle 124 made of a transparent material, held above the base plate 49, which is connected at one end to the second connection 50. At the other end, the Venturi nozzle 124 is connected to the first outlet 51 via an outlet line 78. Pressure measuring bores are provided at various points on the nozzle and diffuser of the Venturi nozzle 124. These are connected to second pressure and reference pressure connections 53.1 to 53.6, 54 protruding from the outside of the Venturi nozzle. The second reference pressure connection 54 is located at the narrowest point of the Venturi nozzle 124. From the other end, a pressure lance 126 projects through a sealing element 125 into the Venturi nozzle. The pressure lance 126, with its inlet opening 127, can be positioned at various positions in the Venturi nozzle 124. At the other end, it is connected to a second pressure connection 53.7.

[0084] According to Fig. 15The eighth test module 48.8 comprises several horizontal, equally long pipes 57.1 to 57.7, which are held parallel to one another on the base plate 49. The pipes 57.1 to 57.7 are connected at the first pipe ends to a distribution block 128, which has the second connection 50. At the second pipe ends, the pipes 57.1 to 57.7 are connected via hand valves 129.1 to 129.7 to a drain block 130, which is connected to the first outlet 51 via an outlet line 78. A second pressure connection 53 is arranged on the distribution block 128, and a second reference pressure connection 54 is arranged on the drain block.

[0085] Pipes 57.1 to 57.7 are designed as follows with and without internals: Pipe 57.1 with large inner diameter and built-in nozzle, pipe 57.2 with large inner diameter and built-in orifice, pipe 57.3 with small inner diameter and built-in nozzle, pipe 57.4 with small inner diameter, S-bend and built-in nozzle, pipe 57.5 with small inner diameter, sharp-edged S-bend and built-in nozzle, pipe 57.6 with small inner diameter, double S-bend and built-in nozzle and pipe 57.7 with small inner diameter, built-in valve and built-in nozzle.

[0086] According to Fig. 16The ninth test module 48.9 comprises horizontal tubes 57.1, 57.2 and tube bundles 131.1 to 131.4 held side by side on a base plate 49. At one end, the tubes 57.1, 57.2 and tube bundles 131.1 to 131.4 are held on the base plate 49 in a first bearing block 132, which has a separate second connection 50.1 to 50.6 for each tube 57.1, 57.2 and each tube bundle 131.1 to 131.4. At approximately two-thirds of their length, the tubes 57.1, 57.2 and tube bundles 131.1 to 131.4 are held on the base plate 49 in a second bearing block 133, which has a separate second pressure connection 53.1 to 53.6 and a separate first vent valve 134.1 to 134.6 for each tube 57.1, 57.2 and each tube bundle 131.1 to 131.4.

[0087] Shortly before their other end (at approximately 95% of their length), the tubes 57.1, 57.2 and tube bundles 131.1 to 131.4 are held on the base plate 49 in a third bearing block 135, which has a separate second reference pressure connection 54.1 to 54.6 and a separate second vent valve 136.1 to 136.6 for each tube 57.1, 57.2 and tube bundles 131.1 to 131.4.

[0088] The tube bundle 131.1 with most of the tubes is additionally held at about 40% of its length on the base plate 49 in a fourth bearing block 137, which has a second pressure connection 53.7 and a third vent valve 137.1.

[0089] The other ends of the tubes are located above a rectangular, second opening 101 in the base plate 49, the main direction of expansion of which is perpendicular to the tubes 57.1, 57.2 and which forms the first outlet 51.

[0090] A rear splash guard 138 projects from the base plate 49 from the edge of the second opening 101 opposite the open ends of the tubes 57.1, 57.2 and tube bundles 131.1 to 131.4. This splash guard is inclined towards the tubes. Short lateral splash guards 139.1, 139.2 project vertically from the base plate 49 from the lateral edges of the second opening 101 parallel to the tubes. In an alternative embodiment, a transparent box is attached to the edge of the second opening 101, which box has rear and lateral splash guards projecting vertically from the base plate 49 from the edge of the second opening 101 opposite the open ends of the tubes and tube bundles and from the lateral edges parallel to the tubes. Above the second opening 101, the box has an upper splash guard. An open-pore foam is attached to the inside of the rear splash guard, which reliably prevents any liquid from splashing back.

[0091] According to Fig. 17The tenth test module 48.10 has horizontal tubes 57.1 to 57.4 held side by side on a base plate 49. These comprise a hydraulically smooth tube 57.1 and a hydraulically rough tube 57.2, which are held at one end in a first bearing block 132 on the base plate 49, which has a separate second connection 50.1, 50.2 for each tube 57.1, 57.2. At approximately 60% of their length, the tubes 57.1, 57.2 are held in a second bearing block 133 on the base plate 49, which has a second pressure connection 53.1, 53.2 and a first vent valve 134.1, 134.2 for each tube 57.1, 57.2. Shortly before their other end (approximately 95% of their length), the tubes 57.1, 57.2 are held in a third bearing block 135, which has a second reference pressure connection 54.1, 54.2 and a second vent valve 136.1, 136.2 for each tube 57.1, 57.2. The other ends of the tubes 57.1, 57.2 are arranged above a rectangular second opening 101 in the base plate 49, the main direction of extension of which is perpendicular to the tubes 57.1, 57.2 and which forms the first outlet 51.

[0092] Next to it, a rectangular tube 57.3 is arranged on the base plate 49, which has the same hydraulic diameter as the two aforementioned tubes 57.1, 57.2. The rectangular tube 57.3 has a second connection 50.3 at one end, a second pressure connection 53.3 at approximately 60% of its length, and a second reference pressure connection 54.3 just before its other end (at approximately 95% of its length). The other end of the rectangular tube is arranged above the second opening 101, so that the test fluid can exit from this end of the rectangular tube 57.3 into the second opening 101.

[0093] In addition, a fourth tube 57.4 is mounted on the base plate 49 in a groove 140, which has a second connection 50.4 at both ends. Between the two ends, a plurality of second pressure or reference pressure connections 53.1 to 53.7, 54.4, 54.5 protrude from the tube, with adjacent connections being aligned alternately in different directions at acute angles to one another to facilitate the attachment of hose couplings to adjacent connections. The tube 57.4 is attached to the groove 140 at both ends by means of clamps 141 and knurled screws 142. This makes it easy to detach the tube 57.4 and insert it into the channel 140 in the reverse orientation.

[0094] In the tenth test module 48.10, the second opening 101 is also enclosed at the edge remote from the tubes 57.1 to 57.4 and at the adjacent lateral edges by splash guards 138, 139.1 and 139.2. According to an alternative embodiment, a transparent box is used as a splash guard, as in the alternative embodiment of FIG. 16 arranged.

[0095] According to Fig. 18 and 19The eleventh test module 48.11 has a horizontal flow channel 143 on the base plate 49 with a front wall 119 made of transparent material. The flow channel 143 extends between a first shaft 144 and a second shaft 145. The first shaft 144 has the second connection 50 on one side. The first shaft 144 is connected to the inlet of the flow channel 143 via a slot nozzle 146 designed as a removable insert, which comprises a horizontal first plate 147 and a second plate 148 inclined relative to it. The slot nozzle 146 is fastened in the flow channel 143, for example, by means of screws. By means of the slot nozzle 146, a very rapid flow of the test liquid can be generated in the flow channel 143. The other end of the flow channel 143 is connected via the second shaft 145 to a second opening 101 in the base plate 49.In addition to the first shaft 144 and the second shaft 145, a second pressure connection 53.1, 53.2 is connected to a bottom wall 149 of the flow channel 143. The bottom wall 149 is made of powder-coated sheet steel. The second pressure connections 53.1, 53.2 extend through two holes in the bottom wall into the flow channel 143. An additional basin 123 with an overflow, which has the second reference pressure connection 54, is located on the base plate 49.

[0096] Mounted on a holder 112 on the base plate 49 are various internal components 150 that can be inserted into the flow channel 143 and secured therein by means of built-in magnets. The internal components 150 are held to the sheet steel base wall 149 by means of the built-in magnets.

[0097] Fig. 20shows a mobile shelf 151 with a shelf frame 152 with rollers 153 and several shelves 154 on which the experimental device 1 and several different experimental modules 48.1 to 48.11 can be stored.

[0098] Further explanations on the use of the experimental equipment follow: Connecting and operating the test modules to the device:

[0099] Modules 48.1 to 48.11 are placed on the main unit 1. The dimensions and markings determine the exact positioning. The main unit recognizes the attached module using an RFID identifier and switches the touch panel 16 to the corresponding mode.

[0100] With the help of the touch panel 16, a structured guide is provided through the modules up to the experiment: The module's information section provides a brief outline of the basic structure and learning content. The experimental setup shows a schematic diagram of the tubing connection to the main water connection and, if necessary, to pressure measurement lines and other measurement connections. The subsequent automatic venting process executes a procedure that expels any air present in the measurement lines and pressure transducers. For the subsequent experiments, there is a help sequence that illustrates the essential sequence of the experiment in a short sequence of images.

[0101] Internet-enabled devices (mobile phones, tablets, PCs) can access the touch panel interface via the internet or a Wi-Fi access point. It is possible to navigate the operator menu independently of the currently displayed interface.

[0102] Operating the main unit via this connection can optionally be specified through programming. Operation and conduct of the experiments:

[0103] Operation is via the built-in touch panel 16. The speed of the first pump 12 can be controlled. Depending on the experiment, control by pressure or flow rate is also possible.

[0104] By controlling the first pump 12, the efficiency is improved compared to throttling. This process is more energy-efficient, resulting in lower heat input.

[0105] It is possible to actively heat the water. This changes the viscosity, which results in changes in the flow pattern. This can be measured in various experiments. The main unit 1 has an internally switchable heating device 37. Alternatively, a chiller can be connected to cool the water, which can be particularly useful in warmer countries. Measuring and recording the measured values:

[0106] The measurement technology is digitized using the touch panel 16. Measurement values ​​from the tests are stored in memory at the touch of a button. A diagram is generated in most module interfaces.

[0107] A magnetic inductive sensor 28 is used to measure the volume flow. These flow meters have high accuracy and a wide measuring range.

[0108] To ensure sufficiently accurate pressure measurement across the measurable flow range, several pressure transducers 30.1 to 30.3 are operated in parallel. The pressure transducers for measuring the low pressures are insensitive to the maximum pressure present. The software uses the output value to determine which transducer to evaluate.

[0109] On some modules, pressures must be measured at various points. Up to seven pressure differentials can be measured using eight mechanical pressure connections (14.1 to 14.7, 15). Solenoid valves (31.1 to 31.7) release one of these pressures. This pressure is then applied to pressure transducers (30.1 to 30.7) and can be adopted after a settling time. If multiple pressures need to be measured at a single flow rate during a test, this can also be done in a single measurement sequence.

[0110] Flow rate, temperature, and pressure are measured using the integrated measurement technology of main unit 1. Each measurement point is assigned a measurement time. This data can be saved as a file, allowing separate evaluation on a PC.

[0111] The user interface is designed in such a way that essential relationships can be captured in the display. It is possible to save the user interface with the display values ​​as an image. Attachable modules:

[0112] All modules 48.1 to 48.11 are designed to ensure maximum measurement accuracy. Minimizing error influences results in good reproducibility.

[0113] All modules have a water connection for water flow. Pressure measurement lines or the connection of additional module-specific measurement equipment depend on the test. First module (48.1) - Visualization of pipe flow:

[0114] The experiment is also known as the "Osborne Reynolds experiment." A stream of tin is visualized in a pipe flow. The jet is clearly visible. Above a certain flow velocity, the first turbulences begin to form. These turbulences increase with increasing flow velocity, until ultimately, no ink jet is visible at all.

[0115] The experiment is available in both a standing and a lying setup. Due to space constraints, the lying setup is used.

[0116] The use of heating demonstrates that there is a temperature influence. This can be explained theoretically using the Reynolds number.

[0117] To visualize a secondary flow, a clear pipe bend 64 (coil) is installed at the end of the pipe section. The flow flows through the pipe bend and forms two counter-rotating vortices within the pipe bend. Second module (48.2) - Measuring the flow profile:

[0118] In this experiment, the fluid flows through a pipe 57. After an inlet section, the flow profile has formed. Essentially, the flow pattern can be divided into laminar and turbulent flow.

[0119] Both flow configurations have the no-slip condition in common, which states that the flow velocity directly at the wall, the wetting first fluid layer, is zero.

[0120] In laminar flow, the flow velocity increases toward the center of the pipe, following a parabolic curve.

[0121] In turbulent flow, the flow velocity also increases. However, the increase in velocity is greater near the wall. In the center of the pipe, the velocity curve is more flattened.

[0122] Using a cannula 71, which is connected to a pressure transducer via a pressure measuring line, the dynamic pressure across the pipe can be measured. This dynamic pressure is the result of the flow velocity. This makes it possible to measure the flow profiles at different Reynolds numbers.

[0123] The flow pattern depends significantly on the Reynolds number and the geometry. The Reynolds number Re is calculated from the flow velocity, the diameter (for the pipe), and the viscosity. The pipe has been extensively studied and is known. The critical Reynolds number Re crit is the flow condition at which the flow no longer returns to laminar flow. If turbulence is induced by disturbances, it cannot subside. However, laminar flow is possible at Reynolds numbers above the critical Reynolds number. This is especially the case in inlet sections. To demonstrate this effect, the module can have two inlet sections: An inlet section for laminar flow. It demonstrates laminar flow and that this can occur even at higher Reynolds numbers than the critical value. This is generated by acceleration in a nozzle. Transitions in the pipe are as smooth as possible. An inlet section for turbulent flow. It demonstrates that the flow behaves differently when turbulence is induced. This is generated by a freestanding, sharp-edged inlet into the pipe being measured. Third Module (48.3) - Visualization of Streamlines:

[0124] By generating hydrogen through electrolysis, the water is not colored by ink, making handling much easier.

[0125] The test specimens 80.1, 80.2 can accelerate the flow by narrowing the cross-section or decelerate it by widening the cross-section.

[0126] In the image, a cleaning slider 89 can be seen from the top left of the transparent windscreen. Dirt and bubbles adhering to the inside can be removed by inserting it into the channel from above and pulling it across the surfaces. Fourth module (48.4) - Continuity equation:

[0127] The module consists of a large-diameter tube 57 through which the fluid flows. A transition reduces the tube to half its cross-section. This increases the flow velocity by a factor of two.

[0128] The flow velocity is indicated by impellers 97 and 98, which are driven by the flow. These impellers have the same pitch. The impeller mounts are also identical.

[0129] To measure the rotational frequency, small, strong magnets are embedded in the impellers. The change in the magnetic field is recorded by sensors. The speed is shown on the display. Fifth Module (48.5) - Measurement of jet forces:

[0130] The module is used to measure the force of a water jet as it hits a body. The deflection of the jet is crucial. The more the jet is deflected, the greater the measured force.

[0131] To demonstrate this, various impact bodies 106 are provided. These are positioned in the beam using a balance beam 105. The balance beam is rotatably mounted, and a force transducer 107 serves as a support on the opposite side of the beam. This force transducer measures the force of the beam. The force transducer is protected from overload by a mechanical stop.

[0132] To demonstrate the influence of the flow rate, two nozzles are provided. The large nozzle has twice the cross-sectional area of ​​the small one. Honeycomb straighteners help create a smooth jet at the nozzle in the short setup.

[0133] Furthermore, the pre-pressure at the nozzle can be measured. This shows which pressure leads to which flow rate and, ultimately, which force is generated.

[0134] The experimental setup is covered by a Plexiglas collecting cylinder 102. This allows the processes to be clearly visible. Sixth Module (48.6) - Free Outflow:

[0135] The device demonstrates the outflow from outlet openings 116 under a given water level.

[0136] The discharge is largely determined by the pressure at the opening. This pressure is determined by the height of the water column. In the sixth module, the water level is automatically adjusted via a control system. The fill level is measured via the water pressure.

[0137] As the pressure increases, the exit velocity at the opening increases. The resulting water jet is a more or less elongated parabola, corresponding to the parabola of projection. This descent of the parabola is measured at specified points using a digital caliper.

[0138] The measured parabola can be compared to a mathematically derived curve.

[0139] The outlet opening is interchangeable. There are four openings in total. The diameter and the inlet of the opening (rounded or sharp-edged) can be varied.

[0140] The different diameters demonstrate the relationship between velocity and volume flow. Different inlets indicate losses at the outlet. With sharp-edged openings, the parabola is less stretched due to additional losses. Seventh Module (48.7) - Bernoulli's Law:

[0141] The seventh module uses a Venturi nozzle to demonstrate the relationship between the conversion of pressure into speed.

[0142] The fluid flows through a Venturi nozzle 124, and the static pressure is measured using pressure measuring holes on the wall. The dynamic pressure can also be measured at these points using an adjustable pressure lance 126.

[0143] The measuring points at the nozzle and diffuser have the same diameters so that the pressure recovery in the diffuser can later be compared with the original pressure.

[0144] Bernoulli’s equation results in a quadratic proportionality between pressure and velocity: Δp ~ c 2<

[0145] The flow velocity also depends on the diameter: c ∼ 1 d 2 It follows: Δ p ∼ c 2 ∼ 1 d 4

[0146] The contour of the nozzle is shaped so that the static pressure falls evenly over the length Δ p~L . The measuring points are evenly distributed - the pressure falls evenly from measuring point to measuring point. The proportionality Δ p ∼ 1 d 4 can be shown so well.

[0147] The Venturi nozzle can be reversed in its design, allowing flow to pass through it in the opposite direction. Higher pressure drops can be demonstrated this way. Deviations from the originally linear curve in the opposite direction indicate separation. Eighth module (48.8) - Losses in piping elements:

[0148] The module contains seven pipe sections (57.1 to 57.7) that build on each other for instructional purposes. These are all installed between a distribution block 128 and a drain block 130. At the end of these sections are hand valves that open the pipe section to be tested. The pressure loss is measured along the entire pipe section.

[0149] The pressure loss is largely determined by the flow velocity. The pressure loss in the pipe fittings under investigation dominates.

[0150] The following fixtures are compared: Nozzle in large pipe Orifice in large pipe Nozzle and small pipe Nozzle and small pipe with S-bend Nozzle and small pipe with sharp-edged S-bend Nozzle and small pipe with double S-bend Nozzle and small pipe with valve installation Ninth Module (49.9) - Fundamentals of Pipe Friction:

[0151] The module is designed to investigate the relationships between pipe friction. It focuses specifically on the use of the Moody diagram, which becomes truly tangible through the use of similarity numbers.

[0152] The Moody diagram is based on dimensionless parameters (Reynolds & pipe friction coefficient) and can therefore be applied to all diameters and flow velocities.

[0153] The six test sections (pipes and tube bundles 57.1, 57.2, 131.1 to 131.4) on the module are intended to: - Demonstrate the transferability of the measured values ​​to the dimensionless parameters. - Cover a maximum range in the diagram, since the individual test sections can only show a limited part of the diagram due to the accuracy of the volume flow and pressure measurements. Therefore, there are overlaps in the measurements from Ø1 to Ø2, for example, with a higher Reynolds number being achieved at the larger diameter. - In particular, proportionalities can be demonstrated, e.g.: Laminar: D p ~ V D p ~ 1 / d 4< Turbulent: Δp ~ V 2<

[0154] The diameters of the pipe sections must be dimensioned to maximize the bandwidth of the first pump. This means low flow at high pressure and vice versa. Lower limits are primarily set for measuring pressure and flow rate. Small-diameter pipes generate a high, easily measurable pressure difference. However, the volumetric flow is very small, so the flow is carried out through several pipes in parallel. This increases the accuracy of the volumetric flow measurement. Large-diameter pipes have an easily measurable flow rate, but the pressure drop cannot be measured at arbitrarily small flow rates.

[0155] Other key features of the module are: Free pipe ends to identify the effects of laminar and turbulent flow on the free jet. The surface of the jet changes from a smooth, transparent structure to a rough, washed-out surface. For a well-developed pipe flow, measurement is taken after a sufficiently long inlet section. The pipe resistance specified in the Moody diagram refers to the fully developed flow. At the pipe inlet, piston flow can initially be assumed. Depending on the exact flow pattern (laminar / turbulent), the development from piston flow to developed flow takes place in the inlet section. The pressure loss is increased in the inlet section. To avoid measuring this increased value, the measurement is only taken at a sufficient distance from the inlet. Tenth module (48.10) - Pressure curve along the inlet section:

[0156] This module expands on the content of module 9. It uses a reference pipe 57.1. This has a diameter of 4 mm and is hydraulically smooth. The pressure drop is measured after an inlet section. The subsequent comparison is made with: Hydraulically rough pipe 57.2. The influence of wall roughness is demonstrated. New: This roughness is created during production using a tap, the tips of which cut a few 1 / 100 mm into the smooth surface of the pipe. Rectangular pipe 57.3 with d hyd equal to 4 mm. A comparison is made with a rectangular pipe. For deviations from the round pipe, the hydraulic diameter is used. Differences are particularly noticeable at the laminar-turbulent transition. These are highlighted.

[0157] Another element is pipe 57.4, which has numerous pressure measurement holes along the inlet section. This is where the pressure loss along the inlet section is measured. This is particularly high at the beginning of the inlet. There are differences in the calming section between laminar and turbulent flow.

[0158] To measure the differences between laminar and turbulent flow, the pipe can be flowed through from both directions. One side is designed as a nozzle to create laminar flow. The other side is a sharp-edged inlet. This creates eddies upon inflow, stimulating turbulence right from the start. For this purpose, the pipe through which the water flows is suspended freely within the larger pipe, which is connected to the water supply.

[0159] In addition to comparing the pressure loss of the inlet section described above, the inlet loss at the constriction can also be measured at both inlets. This is also a frequently encountered case when analyzing losses. Eleventh Module (48.11) - Open Channel:

[0160] The very small flow channel 143 is primarily intended as a demonstration device to demonstrate the use and essential interrelationships of various channel installations 150. For some experiments, the water levels before and after the channel installation are of interest. Two pressure gauge connections are provided for this purpose, allowing the water level to be determined by pressure.

[0161] The following installations are provided to demonstrate energy levels and losses, as well as to determine flow rates: Broad-crested weir with sharp edges Broad-crested weir with rounded edges Round-crested weir Venturi channel piers (energy heights only)

[0162] With the wide installations, the energy dissipation in the stilling basin can be demonstrated: Round-crowned weir with ramp End sill Toothed sill

[0163] The following installation shows how a water level can be regulated: Lifter

[0164] All of these fixtures are secured in the channel with magnets. A steel plate is installed beneath the channel through which the water flows.

[0165] The alternating jump can be examined more closely using the following insert. This insert is permanently mounted: Slot nozzle

[0166] Pressure measurement can be used to measure the water level at the front and rear of the channel. The measured values ​​can be exported to a file and used in subsequent calculations. Furthermore, the values ​​can be used for animations on the display.

[0167] Nozzle 146 creates a rushing flow in the front part of the channel. If this rushing flow is slowed down, a lower flow velocity results at a higher water level. This phenomenon is called a jump.

[0168] The critical velocity for this test is given by the Froude number Fr. At "1," the flow velocity in the channel equals the wave velocity. The wave velocity is calculated from the depth L of the flowing water. The Froude number is the ratio of these: Fr = c g ⋅ L

[0169] To investigate this, a nozzle is installed at the beginning of the channel. This nozzle has a defined height. This allows the flow velocity in the cross-section to be determined using the measured volume flow. The Froude number of the supercritical velocity can be determined from the defined nozzle height and the flow velocity. The height of the transition step can be calculated using a set of formulas as a function of the Froude number. The experiment supports this theoretical calculation. Deviations are discussed.

[0170] Pressure measurements are carried out during the tests with various test modules. The system for measuring pressures and heating / cooling the test fluid is Fig. 3 The main components are explained above.

[0171] In the Fig. 21The same system is shown during pressure measurement. The lines in which the pressure is present during the measurement are highlighted in color. A differential pressure is always measured, with the lower pressure being present at P8. In the example, the pressure at P3 is measured against P8. For this purpose, solenoid valve 33.3 is open, and the remaining solenoid valves 33.1, 33.2, and 33.4 to 33.7, as well as switching valves 39, 41, and 43, are closed.

[0172] Fig. 22illustrates the venting of the pressure connections. The lines through which flow occurs are highlighted in color. In the example, pressure connection p 6 is vented. For this purpose, solenoid valve 33.6 is enabled, and the remaining solenoid valves 33.1 to 33.5 and 33.7 are closed. Furthermore, valve 41 is open, and valves 39 and 43 are closed. The second pump 35 pumps water through the open valves 41 and 33.6 and a connected module 48, taking air in lines 36 and 32 with it. The water flows from module 48 back into the storage tank 24.

[0173] Fig. 23 illustrates the venting of the pressure sensors. Also in Fig. 23The lines through which water flows are highlighted in color. For this purpose, switching valves 41 and 43 are open, and switching valve 39 and solenoid valves 33.1 to 33.7 are closed. Via switching valve 43, line 42 is short-circuited between the pressure side p 1 to p 7 and the side with the lower pressure p 8. The water flows through lines 36, 32, 42, and 31, taking with it the air in the lines and pressure sensors 30.1 to 30.3.

[0174] On both sides of the pressure transducers 30.1 to 30.3, the water is guided from bottom to top in order to reliably vent the pressure transducer chambers.

[0175] Fig. 24 shows the system when heating / cooling the water. Also in Fig. 24The lines through which the water flows are highlighted in color. The first switching valve 39 is open, and the second switching valve 41 is closed. The second pump 35 pumps the water from the storage tank 24 through line 36 and the heating device 37 and the cooling device 38. The water is heated or cooled and returns to the storage tank 24 through line 36.

[0176] The temperature is controlled while the first pump 12 is running to ensure that the temperature is measured via the temperature sensor 29 List of reference symbols

[0177] 1Device 2Tabletop housing 3Lower part 4Control cabinet 5Upper housing wall 6Standing area 7First opening 8Inner step 9Handles 10Front housing wall 11First connection 12First pump 14.1 to 14.7First pressure connection 15First reference pressure connection 16Touch panel 17USB socket 18Multi-pin socket 19First measurement signal connection 20First power connection 21On / off switch 22.1, 22.2Coolant connection 23Frame strip 24Storage container 25Open-pored foam 26Fine-pored foam 27First line 28Volume flow sensor 29Temperature sensor 30.1 to 30.3Pressure sensor 31Second line 32Third line 33.1 to 33.7Solenoid valve 34First Valve block 35second pump 36circulation line 37heating device 38cooling device 39first switching valve 40first connecting line 41second switching valve 42second connecting line 43third switching valve 44second valve block 45computer 46power supply 47reader 48, 48.1 to 48.11experimental module 49base plate 50, 50.1 to 50.6 Second connection 51 First outlet 52 Second outlet 53, 53.1 to 53.7 Second pressure connection 54, 54.1 to 54.6 Second reference pressure connection 55, 55.1, 55.2 Second measurement signal connection 56 RFID 57, 57.1 to 57.7 Pipe 58 Feed device 59, 59.1 to 59.7 First pipe end 60 Container 61 Rod 61.1 Metering valve 62 Feed line 63, 63.1 to 63.7 Second pipe end 64 Pipe bend 65, 65.1, 65.2, 65.3 Bore 66 Nozzle 67 Inlet 68 Collecting container 69 Displacement device 70 Dial gauge 71 Cannula 72, 72.1 to 72.3 Second pressure connection 73 Second reference pressure connection 74.1-74.2 Socket 74.3-74.7 Cable entry 76 Vertical flow channel 77 Front panel 78, 78.1, 78.2 Outlet line 79.1, 79.2 Guide rail 80.1, 80.2 Test body 81 First electrode 82.1, 82.21 Pin 83 Rear panel 84 Second electrode 85.1, 85.2 Screw 86.1, 86.2 Second power connection 87 Drain valve 88 Clamp holder 89 Cleaning slide 90 Handle 91 Cleaning head 92 Rubber cap 93 Handle 94 First pipe section 95 Transition section 96 Second pipe section 97 First impeller 98 Second impeller 99 First scanning device 100 Second scanning device 101 Second opening 102 Collecting cylinder 103 Lever arm 104 Support 105 Lever 106 Impact element 107 Force measuring device 108 Abutment 109 Tube 112 Holder 113 Bushing 115 Cylinder 116 Outlet opening 117 Opening element 118 Shaft 119 Front wall 120 Length measuring device 121 Holder 122 Pair of grooves 123 Basin 124 Venturi nozzle 125 Sealing element 126 Pressure lance 127 Inlet opening 128 Distribution block 129.1 to 129.7 Hand valve 130 Drain block 131.1 to 131.4 Pipe bundle 132 First bearing block 133 Second bearing block 134.1 to 134.6 First vent valve 135 Third bearing block 136.1 to 136.6 Second vent valve 137 Fourth bearing block 137.1 Third vent valve 138 Rear splash guard 139.1, 139.2side splash guard 140gutter 141clamp 142knurled screw 143flow channel 144first shaft 145second shaft 146slot nozzle 147first plate 148second plate 149floor wall 150fittings 151shelf 152shelf frame 153roller 154shelf.

Claims

1. A device for performing flow assays, comprising - a desktop enclosure (2) having a horizontal upper enclosure wall (5) with a placement surface (6) on the upper face and a first opening (7) which is configured therein for positioning a test module (48) having a base plate (49) and a test arrangement for flow assays arranged thereon, - a first connection (11) which is accessible from the outside for connecting a hose to an enclosure wall (10) so that the first connection can be connected by means of a first hose to a second connection (50) of the test module (48) for supplying test fluid into the test arrangement when the test module (48) is positioned on the placement surface (6), - a trough-shaped storage container (24) for test fluid, which is arranged in the desktop enclosure (2) and which is directly accessible from above through the first opening (7) in the placement surface (6) so that test fluid can be discharged from the test arrangement through a first outlet (51) of the test arrangement on the lower face of the base plate (49) into the storage container (24) when the test module (48) is positioned on the placement surface (6), - a first pump (12) which is arranged in the desktop enclosure (2) and which is connected on the inlet side to the interior of the storage container (24) and on the outlet side to the first connection (11), - an electric motor which is arranged in the desktop enclosure (2) and which is coupled to the first pump (12) and - an electric control apparatus (45) which is arranged in the desktop enclosure (2) and which is connected to the electric motor, and which is configured to set the rotational speed of the first pump (12).

2. The device according to claim 1, wherein an inner step (8) which is offset downwardly relative to the placement surface (6) circulates around the inner edge of the first opening (7) for supporting the outer edge of the base plate (49).

3. The device according to claim 1 or 2, wherein at least one layer consisting of an open-pore foam (25, 26) is arranged in the interior of the storage container (24).

4. The device according to claim 3, wherein a first layer consisting of a first open-pore foam (25) is arranged in the interior and a second layer consisting of a second open-pore foam (26) is arranged thereon, wherein the second layer is thinner than the first layer and the second open-pore foam has finer pores than the first open-pore foam.

5. The device according to one of claims 1 to 4, wherein a volume flow measuring sensor (28), preferably a magnetically inductive measuring sensor, is arranged in a first line (27) between the first pump (12) and the first connection (11) for measuring the volume flow of the test fluid.

6. The device according to one of claims 1 to 5, wherein a first reference pressure connection (15) and at least one first pressure connection (14.1 to 14.7) are arranged on an enclosure wall (10) of the desktop enclosure (2) so as to be accessible from the outside, and at least one pressure sensor (30.1 to 30.3) for measuring a differential pressure is arranged in the desktop enclosure (2) and is connected via a second line (31) to the first reference pressure connection (15) and via a third line (32) to the first pressure connection (14.1 to 14.7), so that the first reference pressure connection (15) can be connected via a second hose to a second reference pressure connection (54) of a test arrangement and the first pressure connection (14.1 to 14.7) can be connected via a third hose to a second pressure connection (53) of the test arrangement when the test module (48) is positioned on the placement surface (6).

7. The device according to claim 6, wherein the pressure sensor (30.1 to 30.3) is connected via solenoid valves (33.1 to 33.7) to different first pressure connections (14.1 to 14.7).

8. The device according to claim 6 or 7, which comprises a plurality of pressure sensors (30.1 to 30.3) which are connected in parallel with different measuring ranges.

9. The device according to one of claims 1 to 8, wherein a temperature measuring sensor (29), which acts in the first line (27) between the first pump (12) and the first connection (11) or in the interior of the storage container (24), is arranged in the desktop enclosure (2) in order to measure the temperature of the test fluid.

10. The device according to one of claims 1 to 9, wherein a heating apparatus (37) and / or a cooling apparatus (38), which is integrated in a circulation line (36) with a second pump (35) arranged therein and / or in the storage container (24), is arranged in the desktop enclosure (2) in order to heat and / or to cool the test fluid.

11. The device according to claim 10, wherein the heating apparatus (37) is an electrical resistance heater and / or wherein the cooling apparatus (38) is a heat exchanger which is connected to coolant connections (21.1, 21.2) which are arranged on an enclosure wall and which are accessible from the outside in order to connect this heat exchanger by means of a fourth and a fifth hose to a cold water unit or another coolant source.

12. The device according to one of claims 1 to 11, which comprises an apparatus for venting the apparatuses for measuring the differential pressure (30.1 to 30.3), which apparatus comprises the circulation line (36) and the second pump (35), which is arranged therein, as well as solenoid valves (33.1 to 33.7), by means of which the test fluid can be selectively pumped back through a second line (31) between the pressure sensor (30.1 to 30.3) and the first reference pressure connection (15) and a second hose connected thereto, as well as the test arrangement of a test module (48) which is positioned on the placement surface (6), which test module is connected thereto via the second reference pressure connection (54), and therefrom into the test container (24), or can be pumped back into the storage container (24) through a third line (32) between the pressure sensor (30.1 to 30.3) and the first pressure connection (14.1 to 14.7) and a third hose connected thereto, as well as the test arrangement which is connected thereto via the second pressure connection (53).

13. The device according to one of claims 1 to 12, wherein the first pump (12) is a centrifugal pump and / or wherein the first pump (12) is a submersible pump and / or wherein the second pump (35) is a centrifugal pump and / or wherein the second pump (35) is a submersible pump.

14. The device according to one of claims 1 to 13, which comprises a computer (45) and a touch panel (16) which is connected thereto, which is arranged in a wall of the desktop enclosure (2) and which is accessible from the outside, wherein the computer (45) is configured to display information on the touch panel (16) about the device (1) and / or the test module (48) and / or the learning content and / or the test apparatus and / or the test execution and / or measurement results and / or evaluations of measurement results and / or to control the venting of the apparatuses for measuring the differential pressure (30.1 to 30.3) and / or the execution of tests and / or the detection of measurement results and / or the evaluation of measurement results as a function of inputs via the touch panel (16).

15. The device according to claim 14, wherein the computer (45) is internet-enabled and / or the device comprises a WLAN access point which is networked to the computer.

16. The device according to one of claims 1 to 15, which comprises a reading device (47) for an RFID (56) which is connected to the computer (45) and which is configured to read an identifier stored on an RFID (56) of a test module (48) when this test module is positioned on the placement surface, wherein the computer (45) is configured to control the program sequence as a function of the identifier read by the RFID (56).

17. The device according to one of claims 1 to 16, wherein the desktop enclosure (2) has on an enclosure wall (10) at least one first measurement signal connection (19) which is connected to the computer (45), which is accessible from the outside and which via a first electrical cable can be connected via a second electrical measurement signal connection to an electrical measuring sensor (99, 100, 107) on a test module (48) when this test module is positioned on the placement surface (6).

18. The device according to one of claims 1 to 17, wherein the desktop enclosure (2) comprises a lower part (3) with the placement surface (6) on the upper face and a control cabinet (4) protruding upwardly on the rear edge of the lower part (3), wherein the first pump (12) and optionally the second pump (35) are arranged in the lower part (3) of the storage container (24), and the control apparatus and optionally the measuring sensor (28, 29) and optionally the computer (45) and optionally the touch screen (16) are arranged in the control cabinet (4).

19. The device according to claim 18, wherein the first connection (11) and optionally the first reference pressure connection (15) and the first pressure connection (14.1 to 14.7) and optionally a first measurement signal connection (19), which is accessible from the outside, for an external electrical measuring sensor (20) and optionally first electrical power connections for an external consumer and optionally the touch panel (16), which are accessible from the outside, are arranged in a front enclosure wall (10) of the control cabinet (4) which faces the placement surface (6).

20. The device according to one of claims 1 to 19, wherein the desktop enclosure (2) comprises handles (9) for carrying the desktop enclosure.

21. A test module for performing flow assays, comprising • a base plate (49) for positioning on a placement surface (6) and covering a first opening (7), which is configured therein, relative to a storage container (24) of a device according to claim 1, • a test arrangement for flow assays arranged on the base plate (49), • a second connection (50) for supplying test fluid into the test arrangement by means of a first hose, • a first outlet (51) for test fluid on the lower face of the base plate (49), which first outlet is connected via an apparatus for conducting test fluid to the test arrangement, • and / or a second outlet (52) for test fluid above the base plate (49) for connecting to a drainage line, and ∘ one of the following test arrangements: ∘ a horizontal pipe (57) which consists of a transparent material and which is held on the base plate, a supply apparatus (58) for supplying a marking fluid between a first pipe end (59) of the pipe (57) and the second connection (50), a container (60) for marking fluid which is held above the supply apparatus (58), a metering valve (61.1) which is arranged in a supply line (62) between the container (60) and the supply apparatus (58), a pipe elbow (64) which consists of a transparent material and which is connected to a second pipe end (63) of the pipe (57), and with a second outlet (52) at the other end for connecting to a drainage line or for connecting by means of an outlet line to a first outlet (51) in a bore (65) of the base plate (49); ∘ at least one horizontal pipe (57) which is held on the base plate and which is connected at a first pipe end (59) via a nozzle (66) or a sharp-edged inlet (67) to the second connection (50), the second pipe end (63) thereof being connected to the first outlet (51) via a collection container (68) for test fluid, wherein a cannular (71) engaging in the pipe (57) can be displaced transversely to the pipe cross section in the collection container (68) by means of a displacement apparatus (69) and the cannular (71) is connected to a second pressure connection (53); ∘ a vertical flow channel (76) which has a transparent front plate (77) and which is held on the base plate, which vertical flow channel is connected at the bottom to the second connection (50) and at the top via at least one outlet line (78.1, 78.2) to the first outlet (51), in which at least one test body (80.1, 80.2) is arranged or can be arranged, in which a first electrode (81) at least partially spanning the cross section of the flow channel (76) is arranged below the test body (80.1, 80.2) and in which a second electrode (84) is arranged, wherein the first electrode (81) and the second electrode (84) are connected to second electrical power connections (86.1, 86.2) for connecting an electrical voltage source (HM 250.03); ∘ a pipe (57) which consists of a transparent material and which is held on the base plate, which pipe has at a first pipe end (59) the second connection (50), adjoining thereto a first pipe portion (94) with a greater diameter, adjoining thereto a transition portion (95) which is conical or tapers with a different shape, and adjoining thereto a second pipe portion (96) with a smaller diameter, and which is connected to the first outlet (51) at the other end via an outlet line (78), wherein a first impeller (97) is arranged in the first pipe portion (94) and a second impeller (98) is arranged in the second pipe portion (96), a first scanning apparatus (99) is arranged adjacent to the first pipe portion (94) for scanning the rotational speed of the first impeller (97), a second scanning apparatus (100) is arranged adjacent to the second pipe portion (96) for scanning the rotational speed of the second impeller (98), and the first and second scanning apparatuses (99, 100) are connected to second measurement signal connections (55); ∘ a collection cylinder (102) which has a vertical axis, which is closed at the top and transparent and which is positioned on the edge of the first outlet (51) which is configured as the second opening (101) of the base plate (49), a nozzle (66) which is connected to the second connection and which is oriented vertically upwardly above the first opening in the collection cylinder (102), a baffle element (106) which is held vertically above the nozzle (66) on an arm (103.1) of a lever (105) which is pivotably mounted on a support (104), a force measuring apparatus (107) which is supported, on the one hand, on an abutment (108) and, on the other hand, on the other arm (103.2) of the lever (105), wherein the inlet of the nozzle (66) is connected to the second pressure connection (53) and the force measuring apparatus (107) is connected to the second measurement signal connection (55); ∘ a transparent cylinder (115) which is arranged on the base plate (49) with a vertical axis, with the second connection (50) at the lower end and an outflow opening (116) which is arranged thereabove at the side and to which different opening elements (117) can be interchangeably fastened, a shaft (118) which is open at the top and which is arranged laterally adjacent to the cylinder (115) and which is open toward the outflow opening (116), with an at least transparent front wall (119) which is open at the bottom toward the first outlet (51), which is configured as a second opening (101) in the base plate (49), wherein the shaft (118) is open at the top above the outflow opening (116) and a length measuring apparatus (120) is present which is positioned on the upper edge of the shaft (118) and which can be positioned at different spacings from the outflow opening (116) for measuring the spacing between a test fluid jet emerging from the outflow opening (116) and the upper edge of the shaft (118), wherein the second pressure connection (53) is arranged at the bottom on the cylinder (115) and the second pressure connection (53) is arranged on a tank (123) on the base plate (49); ∘ a horizontal venturi nozzle (124) which consists of a transparent material and which is held above the base plate (49), and which is connected at one end to the second connection (50) and which is connected at the other end via an outlet line (78) to the first outlet (51) of the base plate (49), wherein pressure measuring bores which are connected to second pressure connections and second reference pressure connections (53.1 to 53.8, 54) protruding from the outer face of the venturi nozzle are present at different points of the nozzle and diffuser of the venturi nozzle (124), wherein a pressure lance (126) can be positioned into the venturi nozzle (124) from the other end through a sealing element (125) and with the inlet opening (127) at different axial positions in the venturi nozzle (124), and the pressure lance (126) is connected at the other end to a second pressure connection (53.7); ∘ a plurality of horizontal pipes (57.1 to 57.7) of equal length, having different fittings which are held in parallel adjacent to one another on the base plate (49) and which are preferably selected from a pipe with a large internal diameter and built-in nozzle, a pipe with a large internal diameter and built-in orifice, a pipe with a small internal diameter and built-in nozzle, a pipe with a small internal diameter, S-bend and built-in nozzle, a pipe with a small internal diameter, sharp-edged S-bend and built-in nozzle, a pipe with a small internal diameter, double S-bend and built-in nozzle and a pipe with a small internal diameter, built-in valve and built-in nozzle, wherein the small internal diameter is a smaller internal diameter than the large internal diameter, wherein the pipes (57.1 to 57.7) are connected at first pipe ends to a distributor block (128) which has the second connection (50) and a second pressure connection (53) and the pipes (57.1 to 57.7) are connected via hand levers (129.1 to 129.7) to a drainage block (130) which has a second reference pressure connection (54) and is connected via an outlet line (78) to the first outlet (51) in the base plate (49); ∘ horizontal pipes (57.1, 57.2) and pipe bundles (131.1 to 131.4) which have different internal diameters, which are held adjacent to one another on the base plate (49) and which have in each case the second connection (50.1 to 50.4) at first pipe ends, the second pipe ends thereof opening out in each case above a second opening (101) in the base plate (49), which second opening extends transversely to the pipes and forms the outlet (51) and at the edge remote from the pipes and pipe bundles and at the edges parallel to the pipes and pipe bundles is encompassed by spray protection walls (138, 139.1, 139.2) protruding vertically from the base plate (49), wherein the pipes (57.1, 57.2) and pipe bundles (131.1 to 131.4) in each case have a second pressure connection (53.1 to 53.6) and a first venting valve (134.1 to 134.6) at a spacing from the second connection (50.1 to 50.6), and a second reference pressure connection (54.1 to 54.6) and a second venting valve (136.1 to 136.6) at a further spacing from the second connection, and optionally a pipe bundle has a second pressure connection (53.7) and a third venting valve (137) at a shorter spacing from the second connection; ∘ horizontal pipes (57.1 to 57.4) which are held adjacent to one another on the base plate (49), comprising a hydraulically smooth pipe (57.1), a hydraulically rough pipe (57.2) and a rectangular pipe (57.3) which have in each case a second connection (50.1 to 50.4) at a first pipe end, a second pressure connection (53.1 to 53.3) at a spacing therefrom and a second reference pressure connection (54.1 to 54.3) at a further spacing therefrom, and a pipe (57.4) with more than three pressure measuring bores along an inlet section, the two outer ones thereof being connected to a second reference pressure connection (54.1, 54.2) and the other ones thereof in each case being connected to a second pressure connection (53.1 to 53.7), wherein all of the pipes have a second connection at the first pipe end and only the pipe (57.4) with the more than three pressure measuring bores also has a second connection (50.4) at the second pipe end, and the second pipe ends of all of the pipes (57.1 to 57.4) open out above a second opening (101) in the base plate (49), which second opening extends transversely to the pipes and forms the first outlet (51) and at the edge remote from the pipes (57.1 to 57.4) and at the side edges parallel to the pipes is encompassed by spray protection walls (138, 139.1, 139.2) protruding vertically from the base plate (49); ∘ a horizontal flow channel (143) on the base plate (49) with at least one first front wall (119) consisting of a transparent material, a second connection (50) at the one end of the flow channel (143) and a connection to the first outlet (51) at the other end (of the flow channel (143), a plurality of fittings (150) which can be inserted in the flow channel (143) and fixed therein by means of magnets and a fixedly mountable slot nozzle (146) for demonstrating energy levels and losses and determining flow rates when flowing through the flow channel (143).

22. The test module according to claim 21, comprising a second reference pressure connection (54) and at least one second pressure connection (53) which are connected to the test arrangement and / or at least one second measurement signal connection (55) which is connected to an electrical measuring sensor (99, 100, 107) in the test set-up, and / or second electrical power connections (86.1, 86.2), for connecting to an electrical voltage source, which are connected to an electrical consumer on the base plate (49).

23. The test module according to claim 21 or 22, which comprises an RFID, a readable identifier with an identification of the test module (48) being stored thereon.

24. A system for performing flow assays comprising a device (1) according to one of claims 1 to 20 and at least one test module (48.1 to 48.11) for performing flow assays, comprising • a base plate (49) for positioning on a placement surface (6) and covering a first opening (7), which is configured therein, relative to a storage container (24) of a device according to claim 1, • a test arrangement for flow assays arranged on the base plate (49), • a second connection (50) for supplying test fluid into the test arrangement by means of a first hose, • a first outlet (51) for test fluid on the lower face of the base plate (49), which first outlet is connected to the test arrangement via an apparatus for conducting test fluid, • and / or a second outlet (52) for test fluid above the base plate (49) for connecting to a drainage line.

25. The system according to claim 24, comprising at least one test module according to one of claims 21 to 23.

26. The system according to claim 24 or 25, comprising a movable shelving rack (151) with a plurality of shelves (154) for storing the device (1) and a plurality of test modules (48.1 to 48.11).