A propeller unsteady force testing power instrument and cavitation water tunnel experimental system

Abstract

This invention relates to a propeller unsteady force testing dynamometer and a cavitation tunnel experimental system. The dynamometer includes a sealed housing, an underwater motor, a drive shaft, a propeller model, and an unsteady force sensor. The underwater motor, drive shaft, and unsteady force sensor are located inside the sealed housing, while the propeller model is located outside. The drive shaft includes a front shaft and a rear shaft, with the propeller model mounted on the front shaft. The unsteady force sensor includes a thrust-torque sensor installed between the rear and front shafts and within the sealed housing. The dynamometer also includes a first data cable connected to the thrust-torque sensor and a data acquisition device located outside the sealed housing. This propeller unsteady force testing dynamometer overcomes the limitations of existing testing devices that cannot test propeller unsteady forces or perform tests independently of a cavitation tunnel.

Description

Technical Field

[0001] This invention relates to the field of ship testing, specifically to a propeller unsteady force testing power instrument and a cavitation water tunnel testing system. Background Technology

[0002] The performance tests for propellers include open-water tests and cavitation tunnel tests. In open-water tests, a propeller model is placed in a uniform water flow to test its performance under such conditions. Conventional open-water propeller power instruments are generally suitable for open-water tests under normal pressure. In these tests, the motor is placed on the water and drives the underwater propeller through a right-angle transmission mechanism. This process involves multiple transmission mechanisms, resulting in high noise levels. Furthermore, only the steady values ​​of propeller thrust and torque can be tested.

[0003] In cavitation tunnel experiments, a propeller unsteady force testing dynamometer is placed inside a pipe. The pressure of the water flow inside the pipe can be increased or decreased to simulate different water depths and cavitation numbers, thus enabling testing. Conventional propeller cavitation tunnel equipment only tests the steady values ​​of propeller thrust and torque, which is the basis for setting the hydrodynamic conditions in cavitation experiments. However, with the deepening of research, vibration reduction and noise reduction need to be further improved. The performance of propellers in non-uniform flow behind the ship and the multi-component forces and torques of individual blades are also gradually attracting attention. However, whether in open water experiments or cavitation tunnel experiments, existing propeller steady force testing dynamometers cannot test the relevant performance. Summary of the Invention

[0004] This invention provides a propeller unsteady force testing instrument, which can overcome the shortcomings of existing testing devices that cannot test propeller unsteady forces and cannot be used in conjunction with a cavitation tunnel for testing or can be used independently of a cavitation tunnel for testing.

[0005] The propeller unsteady force testing power instrument of the present invention can be installed in a cavitation water tunnel for experiments, or it can be disassembled from the cavitation water tunnel for experiments independently. It includes a sealed housing, an underwater motor, a power shaft driven by the underwater motor, a propeller model fixed to the end of the power shaft away from the motor, and an unsteady force sensor. The underwater motor, power shaft, and unsteady force sensor are located inside the sealed housing, while the propeller model is located outside the sealed housing. The power shaft includes a front shaft and a rear shaft. The propeller model is mounted on the front shaft, and the rear shaft is connected to the output shaft of the underwater motor via a coupling. The rear shaft is also mounted inside the sealed housing via a thrust bearing. The unsteady force sensor includes a thrust torque sensor installed between the rear shaft and the front shaft and located inside the sealed housing. The testing power instrument also includes a first data cable connected to the thrust torque sensor. Furthermore, the propeller unsteady force testing power instrument includes a data acquisition device located outside the sealed housing. The rear shaft has a slip ring, and the first data cable is connected to the data acquisition device via the slip ring.

[0006] Preferably, the sealing housing is streamlined in shape.

[0007] Preferably, the propeller unsteady force test power instrument further includes an airfoil support, one end of which is connected to the outer wall of the sealed housing, and the other end is detachably connected to the mounting cover of the cavitation water hole. The first data cable is connected to the data acquisition device after passing through the slip ring and the airfoil support in sequence.

[0008] Preferably, the propeller unsteady force test power instrument further includes a rear support, one end of which is detachably connected to the mounting cover of the cavitation water hole, and the other end of which is connected to the outer wall of the sealed housing.

[0009] Preferably, the underwater motor is a brushless DC motor. The propeller unsteady force test power instrument also includes a second data cable connected to the underwater motor at one end and a control device located outside the sealed housing. The rear support is tubular, and the other end of the second data cable passes through the tube of the rear support and is connected to the control device to supply power to the underwater motor and enable the underwater motor to adjust its speed under the control of the control device.

[0010] Preferably, the propeller model includes a hub and multiple blades disposed outside the hub. The unsteady force sensor also includes a single blade root multi-component sensor disposed inside the hub for testing the forces and torques in multiple directions experienced by one of the blades. The propeller unsteady force test power instrument also includes a third data cable, one end of which is connected to the single blade root multi-component sensor, and the other end of which passes through a slip ring and an airfoil support in sequence and is connected to a data acquisition device.

[0011] Preferably, the third data cable is embedded in the power shaft, and the front end of the front axle of the power shaft is provided with a socket for connecting the third data cable, and the single blade root multi-component sensor is plugged into the socket.

[0012] Preferably, the front end and / or rear end of the sealing shell are provided with transparent windows, and the sealing shell is provided with silicone that can change color after absorbing water at the position corresponding to the transparent windows.

[0013] The present invention also provides a cavitation water tunnel experimental system, including a cavitation water tunnel device and a propeller unsteady force testing power instrument as described above. The cavitation water tunnel device includes a cylindrical tunnel body, and the propeller unsteady force testing power instrument is detachably installed in the tunnel body.

[0014] Preferably, the cavitation water tunnel device further includes an external water motor located outside the tunnel and a propeller model located inside the tunnel. The external water motor drives the propeller model of the cavitation water tunnel through a power shaft. The propeller model of the cavitation water tunnel device constitutes the first propeller of the counter-rotating propeller, and the propeller model of the propeller unsteady force test power instrument constitutes the second propeller of the counter-rotating propeller. The second propeller is coaxial with the first propeller and rotates in the opposite direction.

[0015] Preferably, the power shaft of the cavitation water tunnel device includes a front shaft and a rear shaft. A thrust torque sensor is installed between the front shaft and the rear shaft of the cavitation water tunnel device. A first propeller is installed on the front shaft of the cavitation water tunnel device and can rotate synchronously with it. The first propeller includes a hub and multiple blades disposed outside the hub. A single blade root multi-component sensor for testing the forces and torques in multiple directions experienced by one of the blades is disposed inside the hub of the first propeller.

[0016] Preferably, the first propeller and the second propeller are the two propellers of a counter-rotating propeller pump.

[0017] Compared with the prior art, the present invention has the following advantages:

[0018] The propeller unsteady force testing dynamometer of this invention has a complete drive system, built-in sensors, and related cables, forming an independent testing system. When the drive system drives the propeller model, the propeller model rotates, generating thrust, which is then transmitted to the thrust torque sensor via the front shaft. This sensor is an unsteady force testing sensor that can measure both steady and unsteady forces of the entire propeller. The underwater motor, drive shaft, and thrust torque sensor are all located within a sealed housing, allowing for installation in a cavitation tunnel for cavitation tunnel experiments. This simple and convenient addition of a device for testing propeller unsteady forces within a cavitation tunnel overcomes the limitation of conventional tunnels that only measure steady propeller forces. Furthermore, the propeller unsteady force testing dynamometer of this invention, in conjunction with existing cavitation tunnel dynamometers, can also perform counter-rotating propeller or pump tests with arbitrary front and rear propeller speed ratios within the cavitation tunnel. Additionally, the propeller unsteady force testing dynamometer of this invention can also be completely disassembled from the cavitation tunnel for independent experiments.

[0019] 2. In the cavitation water tunnel experimental system of the present invention, the first and second propellers are driven by different drive mechanisms. The rotational speed of the second propeller can be arbitrarily adjusted as needed, thereby obtaining different speed ratios between the two propellers, which allows for testing the force conditions of the two propellers under different speed ratios. It can also test the force conditions of counter-rotating propeller pumps. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of a propeller unsteady force test power instrument and a cavitation water tunnel mounting cover plate installed together according to an embodiment of the present invention.

[0021] Figure 2 A schematic diagram of the structure of the propeller unsteady force testing power instrument according to an embodiment of the present invention after the propeller model is disassembled and the mounting cover plate of the cavitation water hole is removed.

[0022] Figure 3 A schematic diagram of the structure of a cavitation water tunnel experimental system according to an embodiment of the present invention.

[0023] Figure 4 A schematic diagram of the structure of a cavitation water tunnel experimental system according to another embodiment of the present invention.

[0024] Figure 5 A schematic diagram of the structure of a propeller unsteady force testing power instrument for performance testing of a counter-rotating propeller pump according to another embodiment of the present invention.

[0025] Attached Figure

[0026] 1 sealed housing, 11 transparent windows;

[0027] 2 Second drive shaft, 21 Second front shaft, 211 Connecting key, 212 Bearing, 213 Socket, 22 Second rear shaft, 221 Slip ring, 222 Thrust bearing, 23 Second thrust torque sensor, 24 Coupling;

[0028] 3 Propeller model, 31 Second hub, 32 Second blade, 33 Second single blade root multi-component sensor;

[0029] 4 underwater motors;

[0030] 5. Airfoil support;

[0031] 6. Support after the event;

[0032] 7. Install the cover plate;

[0033] 8-hole structure;

[0034] 9-pair propeller pumps;

[0035] A. First propeller;

[0036] B is the second propeller. Detailed Implementation

[0037] The propeller unsteady force testing power instrument provided by this invention can be installed inside a cavitation water tunnel for experiments, or it can be removed from the cavitation water tunnel for separate experiments. For example... Figure 1 and Figure 2As shown, the propeller unsteady force testing power instrument of this embodiment includes a sealed housing 1, an underwater motor 4, a second power shaft 2 driven by the underwater motor 4, a propeller model 3 fixed to the end of the second power shaft 2 away from the underwater motor 4, and an unsteady force sensor. The underwater motor 4, the second power shaft 2, and the unsteady force sensor are located inside the sealed housing 1. The propeller model 3 includes a second hub 31 and a plurality of second blades 32 disposed outside the second hub 31. The second hub 31 and the second blades 32 are located outside the sealed housing 1. The second power shaft 2 includes a second front shaft 21 and a second rear shaft 22. The propeller model 3 is mounted on the second front shaft 21. The second front shaft 21 is close to the propeller model 3. The second rear shaft 22 is mounted to the inner wall of the sealed housing 1 via bearing 212. The second rear shaft 22 is connected to the output shaft of the underwater motor 4 via coupling 24. Simultaneously, the second rear shaft 22 is mounted to the inner wall of the sealed housing 1 via thrust bearing 222. The unsteady force sensor includes a second thrust-torque sensor 23 installed between the second rear shaft 22 and the second front shaft 21, located within the sealed housing 1. The test power instrument also includes a first data cable (not shown) connected at one end to the second thrust-torque sensor 23. The propeller unsteady force test power instrument also includes a data acquisition device (not shown) located outside the sealed housing 1, typically positioned above the water surface. The second rear shaft 22 is equipped with a slip ring 221. The first data cable passes through the slip ring 221 and connects to the data acquisition device, enabling data transmission between the second thrust-torque sensor 23 and the data acquisition device.

[0038] The propeller unsteady force testing power instrument of the present invention has a complete drive system, built-in sensors and related cables, forming an independent testing system. When the underwater motor 4 drives the propeller model 3 through the second power shaft 2, the propeller model 3 rotates and generates thrust, which is then transmitted to the second thrust torque sensor 23 through the front shaft 21 of the second power shaft 2. This sensor is an unsteady force sensor that can measure the steady and unsteady forces of the entire propeller. The underwater motor 4, the second power shaft 2 and the thrust torque sensor 23 are all located inside the sealed housing 1. The entire power instrument can be installed in a cavitation tunnel to conduct cavitation tunnel experiments. It simply and conveniently adds equipment for testing the unsteady force of the propeller in a cavitation tunnel, making up for the deficiency of conventional water tunnels that only have built-in drive devices for measuring the steady force of the propeller.

[0039] Furthermore, the propeller unsteady force testing dynamometer of this invention, in conjunction with an existing dynamometer for cavitation tunnels, can also conduct counter-rotating propeller or counter-rotating propeller pump tests within cavitation tunnels with arbitrary front-to-rear propeller speed ratios. The specific method will be described in detail when introducing the cavitation tunnel experimental system. This is also required for hydrodynamic research on counter-rotating propellers or counter-rotating propeller pumps, where the front-to-rear propeller speed ratio of current counter-rotating propeller testing instruments is fixed, failing to meet the testing requirements for arbitrary speed ratios. Additionally, as... Figure 2 As shown, the propeller unsteady force test power instrument of the present invention can also be completely disassembled from the cavitation water tunnel and tested separately.

[0040] like Figure 1 and Figure 2 As shown, the sealing housing 1 has a streamlined shape, which can reduce the impact of water flow, such as Figure 3 As shown, even when installed in a small cross-section flow field (cavitation water tunnel), more accurate test data can be obtained.

[0041] The propeller unsteady force testing power instrument also includes an airfoil support 5, which comprises a plate parallel to the axial direction of the second power shaft 2. One end of the airfoil support 5 is connected to the outer wall of the sealed housing 1, and the other end is detachably connected to the mounting cover plate 7 of the cavitation water tunnel. The first data cable passes sequentially through the slip ring 221 and the airfoil support 5 and is then connected to the data acquisition device. During testing, the plate of the airfoil support 5 is parallel to the direction of water flow, which minimizes the impact on the water flow and thus makes the test more accurate. The propeller unsteady force testing power instrument is detachably connected to the mounting cover plate 7 of the cavitation water tunnel, allowing the propeller unsteady force testing power instrument to be conveniently installed in or removed from the cavitation water tunnel.

[0042] The propeller unsteady force test power instrument also includes a rear support 6. One end of the rear support 6 is detachably connected to the mounting cover plate 7 of the cavitation water hole, and the other end is connected to the outer wall of the sealing housing 1. The rear support 6 can strengthen the connection between the propeller unsteady force test power instrument and the cavitation water hole.

[0043] The underwater motor 4 is a brushless DC motor. The propeller unsteady force testing power instrument also includes a second data cable (not shown in the figure) connected to the underwater motor 4 at one end and a control device (not shown in the figure) located outside the sealed housing 1. When the power instrument is used for open-water experiments, the control device is located on the water surface. When the power instrument is installed inside a cavitation hole for cavitation experiments, the control device is located outside the cavitation hole. As a preferred embodiment, the rear support 6 is tubular, and the other end of the second data cable passes through the tube of the rear support 6 along the axial direction of the tube and connects to the control device, allowing the underwater motor 4 to adjust its speed under the control of the control device. This speed can be arbitrarily adjusted as needed, thereby providing more testing conditions for unsteady force testing. The second data cable can also be used to feed back the motor speed to the control device and to supply power to the underwater motor 4.

[0044] The unsteady force sensor also includes a second single-blade root multi-component sensor 33 disposed within the second blade hub 31 for testing the forces and torques acting on one of the second blades 32 in multiple directions. The propeller unsteady force testing power instrument also includes a third data cable (not shown in the figure), one end of which is connected to the single-blade root multi-component sensor 33, and the other end passes through the slip ring 221 and the airfoil support 5 before connecting to the data acquisition device. The second single-blade root multi-component sensor 33 can be used to test the forces and torques acting on a single second blade 32 in multiple directions.

[0045] In this embodiment, a connecting key 211 is provided at the front end of the second front shaft 21, and the propeller model 3 is connected to the second front shaft 21 via the connecting key 211. The third data cable is embedded inside the second power shaft 2, and the front end of the front shaft 21 of the second power shaft 2 is provided with a socket 213 for connecting the third data cable. The second single-propeller root multi-component sensor 33 is plugged into the socket 213 to realize data transmission. This structure allows the third data cable and the second single-propeller root multi-component sensor 33 to be connected or disconnected more conveniently.

[0046] The front end of the sealing housing 1 is provided with a transparent window 11, which can be made of plexiglass and can be hemispherical. Inside the sealing housing 1, at a position corresponding to the transparent window 11, there is a silicone sealant that changes color after absorbing water. If the silicone sealant changes color, it can visually indicate that the seal has failed.

[0047] The present invention also provides a cavitation water tunnel experimental system, one embodiment of which is, for example... Figure 3 As shown, the cavitation water tunnel experimental system includes a cavitation water tunnel device and a propeller unsteady force testing power instrument as described above. The cavitation water tunnel device includes a cylindrical tunnel body 8, and the propeller unsteady force testing power instrument is detachably installed inside the tunnel body 8.

[0048] Figure 4 The diagram shows another embodiment of the cavitation water tunnel experimental system. In this embodiment, the cavitation water tunnel experimental system includes a cavitation water tunnel device and a propeller unsteady force testing power instrument as described above. The cavitation water tunnel device includes a cylindrical tunnel body 8, and the propeller unsteady force testing power instrument is detachably installed inside the tunnel body 8. The cavitation water tunnel device also includes an external water motor located outside the tunnel body 8 and a propeller model located inside the tunnel body 8 and driven to rotate by the external water motor. The external water motor drives the propeller model of the cavitation water tunnel device to rotate through a first power shaft. The propeller model of the cavitation water tunnel device constitutes a first propeller A of a counter-rotating propeller. The testing power instrument is installed inside the tunnel body 8, and the propeller model of the propeller unsteady force testing power instrument constitutes a second propeller B of the counter-rotating propeller. The second propeller B is coaxial with the first propeller A and rotates in the opposite direction. Here, coaxial does not mean that they are installed on the same shaft, but that their rotation axes are on the same axis.

[0049] In the cavitation water tunnel experimental system of the present invention, the first propeller A and the second propeller B are driven by different drive mechanisms. The rotational speed of the second propeller B can be arbitrarily adjusted as needed, thereby obtaining different speed ratios of the two propellers, and thus testing the force conditions of the two propellers under different speed ratio conditions.

[0050] The first power shaft of the cavitation water tunnel device includes a first front shaft and a first rear shaft (not shown in the figure). A first thrust-torque sensor (not shown in the figure) is installed between the first front shaft and the first rear shaft. The first thrust-torque sensor can be a steady force sensor or an unsteady force sensor. The first propeller A includes a first hub and multiple first blades disposed outside the first hub. A first single blade root multi-component sensor is installed inside the first hub of the first propeller A to test the forces and torques in multiple directions experienced by one of the first blades. The first single blade root multi-component sensor can be a steady force sensor or an unsteady force sensor. In this way, the thrust, torque, and multi-component forces of a single blade experienced by the two propellers under different speed ratios can be tested, allowing for both steady and unsteady force testing.

[0051] Figure 5 The image shows another embodiment of the cavitation water tunnel experimental system. In this embodiment, the cavitation water tunnel experimental system, in addition to having... Figure 4 In addition to all the structures shown in the embodiment, it also has the following feature: the first propeller A and the second propeller B are the two propellers of the counter-rotating propeller pump 9. The force conditions of the counter-rotating propeller pump 9 can be tested using the cavitation water tunnel experimental system of the present invention.

[0052] The above embodiments are merely exemplary embodiments of the present invention and are not intended to limit the present invention. The scope of protection of the present invention is defined by the claims. Various modifications or equivalent substitutions made by those skilled in the art to the present invention within its spirit and scope of protection also fall within the scope of protection of the present invention.

Claims

1. A cavitation water tunnel experimental system, characterized in that, The device includes a cavitation water tunnel device and a propeller unsteady force testing power instrument. The cavitation water tunnel device includes a cylindrical tunnel body, and the propeller unsteady force testing power instrument is detachably installed inside the tunnel body. The cavitation water tunnel device also includes an external water motor located outside the tunnel and a propeller model located inside the tunnel. The external water motor drives the propeller model of the cavitation water tunnel through a first power shaft. The propeller model of the cavitation water tunnel device constitutes the first propeller of a counter-rotating propeller. The first power shaft of the cavitation water tunnel device includes a first front shaft and a first rear shaft. A first thrust torque sensor is installed between the first front shaft and the first rear shaft of the cavitation water tunnel device. The first propeller is installed on the first front shaft of the cavitation water tunnel device and can rotate synchronously with it. The first propeller includes a first hub and multiple first blades located outside the first hub. A first single blade root multi-component sensor is installed in the first hub of the first propeller for testing the forces and torques in multiple directions experienced by one of the first blades. The propeller unsteady force testing power instrument includes a sealed housing, an underwater motor, a second power shaft driven by the underwater motor, a propeller model fixed to the end of the second power shaft away from the underwater motor, and an unsteady force sensor. The underwater motor, the second power shaft, and the unsteady force sensor are located inside the sealed housing, while the propeller model of the propeller unsteady force testing power instrument is located outside the sealed housing. The second power shaft includes a second front shaft and a second rear shaft. The propeller model of the propeller unsteady force testing power instrument is mounted on the second front shaft, and the second rear shaft is connected to the output shaft of the underwater motor via a coupling. Meanwhile, the... The second rear shaft is mounted in the sealed housing via a thrust bearing. The unsteady force sensor includes a second thrust torque sensor installed between the second rear shaft and the second front shaft and located within the sealed housing. The test power instrument also includes a first data cable connected to the second thrust torque sensor. The propeller unsteady force test power instrument also includes a data acquisition device located outside the sealed housing. The second rear shaft is provided with a slip ring. The first data cable is connected to the data acquisition device after passing through the slip ring. The propeller model of the propeller unsteady force test power instrument constitutes a second propeller to the counter-rotating propeller. The second propeller is coaxial with the first propeller and rotates in the opposite direction.

2. The cavitation water tunnel experimental system according to claim 1, characterized in that, The sealed housing has a streamlined shape.

3. The cavitation water tunnel experimental system according to claim 2, characterized in that, The propeller unsteady force test power instrument also includes an airfoil support. One end of the airfoil support is connected to the outer wall of the sealed housing, and the other end is detachably connected to the mounting cover of the cavitation water hole. The first data cable passes through the slip ring and the airfoil support in sequence and is then connected to the data acquisition device.

4. The cavitation water tunnel experimental system according to claim 3, characterized in that, The propeller unsteady force test power instrument also includes a rear support, one end of which is detachably connected to the mounting cover plate of the cavitation water hole, and the other end of which is connected to the outer wall of the sealed housing.

5. The cavitation water tunnel experimental system according to claim 4, characterized in that, The underwater motor is a brushless DC motor. The propeller unsteady force test power instrument also includes a second data cable connected to the underwater motor at one end and a control device located outside the sealed housing. The rear support is tubular. The other end of the second data cable passes through the tube of the rear support and is connected to the control device to supply power to the underwater motor and enable the underwater motor to adjust its speed under the control of the control device.

6. The cavitation water tunnel experimental system according to claim 3, characterized in that, The propeller unsteady force test power instrument includes a propeller model comprising a second hub and multiple second blades disposed outside the second hub. The unsteady force sensor also includes a second single blade root multi-component sensor disposed inside the second hub for testing the forces and torques in multiple directions experienced by one of the second blades. The propeller unsteady force test power instrument also includes a third data cable, one end of which is connected to the second single blade root multi-component sensor, and the other end of which passes through a slip ring and an airfoil support in sequence and is connected to a data acquisition device.

7. The cavitation water tunnel experimental system according to claim 6, characterized in that, The third data cable is embedded in the second power shaft. The front end of the front shaft of the second power shaft is provided with a socket for connecting the third data cable. The second single blade root multi-component sensor is plugged into the socket.

8. The cavitation water tunnel experimental system according to claim 1, characterized in that, The front and / or rear end of the sealed housing of the propeller unsteady force testing power instrument is provided with a transparent window, and the sealed housing is provided with silica gel that can change color after absorbing water at the position corresponding to the transparent window.

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