A kind of object surface microstructure and bubble composite drag reduction measurement experimental device based on Taylor-Couette flow

Abstract

The application provides a Taylor-Couette flow-based object surface microstructure and bubble composite drag reduction measurement experimental device, and relates to the Taylor-Couette flow drag reduction measurement technical field, and comprises a rack support column, a rack support plate, a motor, an upper coupling, a torque sensor, an inner driving shaft, a lower coupling, a mechanical seal, an upper end sealing connector, an inner rotor, an outer rotor, a lower end sealing connector, a support column, a rack base, a one-way air valve and a bottom plate; the application can conveniently replace different inner rotors with surface microstructures and smooth surfaces according to experimental requirements; the application can switch between two air supply modes, i.e., air supply from the inner rotor to the outside and air supply from the bottom to the top; through a gas flow meter and a motor controller, the application can control the flow under different rotating speeds and gas flows; the torque sensor can be used to measure the resistance borne by the inner rotor under different flow conditions in real time, so that the surface microstructure and bubble composite drag reduction characteristics under Taylor-Couette flow can be researched.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of Taylor-Couette flow drag reduction measurement, and particularly relates to a Taylor-Couette flow-based object surface microstructure and bubble composite drag reduction measurement experimental device. BACKGROUND

[0002] During the navigation process of surface ships and underwater vehicles, the propulsion energy consumption mainly comes from fluid resistance work. In order to reduce fuel consumption, reduce pollution emissions and improve speed and range, drag reduction technology has been widely used in the design of ships and underwater vehicles. At present, underwater drag reduction technologies mainly include: object surface microstructure drag reduction (such as groove or corrugated surface), bubble drag reduction (by injecting bubbles to form a gas film), hydrophobic / super-hydrophobic surface drag reduction (using surface hydrophobicity to reduce drag) and the like.

[0003] Previous studies on drag are mostly based on channel flow, plate flow and cavity flow, etc. Since the flow may exhibit spatial dependence or time dependence, it is difficult to induce the drag reduction data of different experimental devices into a unified conclusion, which brings difficulties to the general explanation of the drag reduction mechanism. The Taylor-Couette (TC) flow system overcomes these problems, because in the TC flow, statistical steady state is easy to achieve, and the system is a closed system with clear energy balance, which can measure the global torque and gas volume fraction with high precision, and directly relates the influence of bubbles or microstructures on drag. Although so, the existing drag reduction research using the TC flow device often only considers one aspect, such as only bubble drag reduction research or only considering the effect of object surface microstructure on drag reduction. These single studies often have certain limitations, because in actual application, the drag reduction effect often depends on the synergistic effect of multiple factors (such as the coupling effect of super-hydrophobic grooves and bubble injection). And the existing TC flow device is out of touch with the actual scene, and the existing TC flow device mostly adopts bottom vertical ventilation, while the ship drag reduction system usually releases bubbles through the ship wall or surface microstructure, which leads to significant differences between experimental conditions and engineering applications. Therefore, an experimental device is needed that can simulate complex actual environment and support multi-factor synergistic drag reduction research, to reveal the coupling mechanism of bubbles and microstructures and provide a theoretical basis for engineering applications.

[0004] In order to solve the above problems, the application provides a Taylor-Couette flow-based object surface microstructure and bubble composite drag reduction measurement experimental device, which can realize convenient replacement of different inner rotor modules with surface microstructure and smooth surface according to experimental requirements. And various ventilation methods such as inner rotor internal ventilation or bottom vertical ventilation can be used, aiming to realize the research on the surface microstructure and bubble composite drag reduction mechanism of the inner rotor through the ventilation environment closer to the actual application, and provide theoretical support and technical means for the application in the related field. SUMMARY

[0005] In order to solve the above technical problems, the application provides a Taylor-Couette flow-based object surface microstructure and bubble composite drag reduction measurement experimental device, which can realize the adjustment of different rotating speeds and airflow flow rates under the flow control.

[0006] To this end, the present application provides a kind of object surface microstructure and bubble composite drag reduction measurement experimental device based on Taylor-Couette flow, including frame support column, frame support plate, motor, upper coupling, torque sensor, inner drive shaft, lower coupling, mechanical seal, upper end sealing connector, inner rotor, outer rotor, lower end sealing connector, support column, frame base, one-way air valve and bottom plate, the frame support column is installed at one end above the frame base;The one end of the frame support plate is installed on the frame support column, and the frame support plate is parallelly aligned with the frame base;The motor is installed at the end of the frame support plate away from the frame support column, and the output shaft of the motor penetrates to the underside of the frame support plate;The inner drive shaft is connected with the output shaft of the motor by the upper coupling;The torque sensor is sleeved on the outside of the inner drive shaft, and the torque sensor is slidably arranged with the inner drive shaft, which is connected with the underside of the frame support plate;The inner rotor is coaxially installed at the lower end of the inner drive shaft by the lower coupling;The bottom plate is arranged above the frame base by the support column;The outer rotor is fixed above the bottom plate, and the lower end of the outer rotor is provided with a lower end sealing connector, and the upper end of the outer rotor is provided with an upper end sealing connector, wherein the outer rotor is coaxially sleeved outside the inner rotor;A ring gap is left between the inner rotor and the outer rotor;The bottom plate is provided with a plurality of one-way air valves around the central axis;The one-way air valve is located in the ring gap;The mechanical seal is arranged at the connection between the upper end sealing connector and the inner drive shaft;By setting the motor, the inner rotor, the outer rotor and the one-way air valve, viscous fluid is arranged between the inner rotor and the outer rotor, the one-way air valve is used to transport bubbles to the viscous fluid, the motor drives the inner rotor to rotate, and the inner rotor is replaced between different inner rotors with surface microstructure and smooth surface according to experimental requirements, so as to facilitate the research in the field of bubble Taylor-Couette flow drag reduction measurement technology, the structure is simple, one motor can meet the research requirements, the cost is low, the speed of the motor is controlled by the controller, the flow of the bubble is controlled by the bubble generator, and the control of different rotating speeds and gas flows can be realized.

[0007] Further, the inner drive shaft and the upper end sealing connector are sleeved with a sliding bearing;The upper end sealing connector and the outer rotor adopt static sealing;The one-way air valve adopts static sealing between the upper end and the lower end sealing connector, and the one-way air valves are arranged at equal intervals, and the lower end of the one-way air valve is connected with the bubble generator through a pipeline, wherein the one-way air valve is used to prevent the viscous fluid from flowing out of the outer rotor through the one-way air valve;The motor output shaft, the upper coupling, the inner drive shaft, the lower coupling, the inner rotor and the outer rotor are coaxially and vertically arranged on the frame base.

[0008] Further, the motor is connected with an external power supply and a controller through wires for controlling the rotating speed of the motor; the torque sensor is connected with the external power supply and the controller through wires for monitoring the torque of the inner rotor; the plurality of struts are arranged around the central shaft of the base plate, and the struts are used for adjusting the support of the base plate, wherein the struts are arranged at equal intervals; the torque sensor is used for monitoring the torque of the inner drive shaft, the inner drive shaft rotates synchronously with the inner rotor, and the change of the torque of the inner rotor due to the addition of the bubbles is convenient for research, which is of great significance for understanding and optimizing the fluid mechanics system related to the bubbles; the struts are arranged below the base plate, the base plate is adjusted through the struts, the motor output shaft, the upper coupling, the inner drive shaft, the lower coupling, the inner rotor and the outer rotor are coaxially and vertically arranged, and the working efficiency of the measuring device is improved.

[0009] Further, the inner rotor adopts a detachable structure, different inner rotor modules such as surface microstructure and smooth surface of the inner rotor can be conveniently replaced according to experimental requirements, the inner rotor adopts switching of two ventilation modes of internal outward ventilation and bottom vertical upward ventilation, and the ventilation environment is closer to the actual application.

[0010] Compared with the prior art, the present application has the following beneficial effects:

[0011] 1、In the present application, the motor, the inner rotor, the outer rotor and the one-way air valve are arranged, the viscous fluid is arranged between the inner rotor and the outer rotor, the bubbles are transported to the viscous fluid through the one-way air valve, the motor drives the inner rotor to rotate, the inner rotor is replaced among different inner rotors with surface microstructure and smooth surface according to experimental requirements, the research on the influence of bubbles on the drag reduction of Taylor-Couette flow is facilitated, the structure is simple, one motor can meet the research requirements, the cost is low, the rotating speed of the motor is controlled through the controller, the flow of the bubbles is controlled through the bubble generator, and the control of different rotating speeds and gas flow can be realized.

[0012] 2、In the present application, the torque sensor is arranged, the torque sensor is used for monitoring the torque of the inner drive shaft, the inner drive shaft rotates synchronously with the inner rotor, the change of the torque of the inner rotor due to the surface microstructure of the inner rotor and the addition of the bubbles is convenient for research, and the research on the combined drag reduction mechanism of the surface microstructure of the inner rotor and the bubbles is realized.

[0013] 3、In the present application, the struts are arranged below the base plate, the base plate is adjusted through the struts, the motor output shaft, the upper coupling, the inner drive shaft, the lower coupling, the inner rotor and the outer rotor are coaxially and vertically arranged, and the working efficiency of the measuring device is improved.

[0014] 4、The present application can realize the switching of the two ventilation modes of the internal ventilation of the inner rotor and the vertical upward ventilation of the bottom, so as to be closer to the ventilation environment of the actual application. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 is a structural schematic diagram of the present application;

[0016] Figure 2 is a structural schematic diagram of the inner rotor with a surface microstructure of the present application;

[0017] Figure 3 is a result schematic diagram of the inner rotor adopting the internal ventilation mode of the inner rotor of the present application;

[0018] Figure 4 is a sectional view of A-A in the present application; Figure 3

[0019] Figure 5 is a sectional view of B-B in the present application; Figure 3

[0020] Figure 6 is a structural schematic diagram of the rack support column, the inner rotor, the outer rotor, the rack base and the one-way ventilation valve of the present application;

[0021] Figure 7 is a structural schematic diagram of the one-way ventilation valve of the present application.

[0022] In the drawings:

[0023] 1, rack support column; 2, rack support plate; 3, motor; 4, upper coupling; 5, torque sensor; 6, inner drive shaft; 7, lower coupling; 8, mechanical seal; 9, upper end sealing connecting piece; 10, inner rotor; 11, outer rotor; 12, lower end sealing connecting piece; 13, support column; 14, rack base; 15, one-way ventilation valve; 16, bottom plate. DETAILED DESCRIPTION

[0024] The present application will be further described below in combination with the drawings:

[0025] Embodiment:

[0026] As shown in the accompanying drawings Figure 1 to Figure 7 as shown

[0027] ​​The application provides a kind of object surface microstructure and bubble composite drag reduction measurement experimental device based on Taylor-Couette flow, including frame support column 1, frame support plate 2, motor 3, upper coupling 4, torque sensor 5, inner drive shaft 6, lower coupling 7, mechanical seal 8, upper end sealing connector 9, inner rotor 10, outer rotor 11, lower end sealing connector 12, support column 13, frame base 14, one-way air valve 15 and bottom disc 16, frame support column 1 is installed at one end above frame base 14;One end of frame support plate 2 is installed on frame support column 1, and frame support plate 2 is parallel to frame base 14;Motor 3 is installed on the end of frame support plate 2 away from frame support column 1, and the output shaft of motor 3 penetrates to the lower side of frame support plate 2;Inner drive shaft 6 is connected with the output shaft of motor 3 through upper coupling 4;Torque sensor 5 is sleeved on the outer side of inner drive shaft 6, and torque sensor 5 is slidably arranged with inner drive shaft 6, and torque sensor 5 is connected with the lower side of frame support plate 2;Inner rotor 10 is coaxially installed at the lower end of inner drive shaft 6 through lower coupling 7;Bottom disc 16 is arranged above frame base 14 through support column 13;Outer rotor 11 is fixed above bottom disc 16, and the lower end of outer rotor 11 is provided with lower end sealing connector 12, and the upper end of outer rotor 11 is provided with upper end sealing connector 9, wherein outer rotor 11 is coaxially sleeved outside inner rotor 10;There is an annular gap between inner rotor 10 and outer rotor 11;Bottom disc 16 is provided with a plurality of one-way air valves 15 around the central axis;One-way air valve 15 is located in the annular gap;Mechanical seal 8 is arranged at the connection between upper end sealing connector 9 and inner drive shaft 6;By arranging motor 3, inner rotor 10, outer rotor 11 and one-way air valve 15, viscous fluid is arranged between inner rotor 10 and outer rotor 11, gas bubbles are transported to viscous fluid through one-way air valve 15, motor 3 drives inner rotor 10 to rotate, which facilitates the research on the influence of gas bubbles on Taylor-Couette flow drag reduction measurement, and the structure is simple, one motor 3 can meet the research requirements, the cost is low, the speed of motor 3 is controlled by controller, the flow of gas bubbles is controlled by bubble generator, and the control of different speed and gas flow can be realized.

[0028] In this embodiment, specifically, a sliding bearing is sleeved between inner drive shaft 6 and upper end sealing connector 9;Upper end sealing connector 9 and outer rotor 11 adopt static sealing;One-way air valve 15 adopts static sealing between upper end and lower end sealing connector 12, and one-way air valve 15 is arranged at equal intervals, and the lower end of one-way air valve 15 is connected with bubble generator through pipeline, wherein one-way air valve 15 is used to prevent viscous fluid from flowing out of outer rotor 11 through one-way air valve 15;Motor 3 output shaft, upper coupling 4, inner drive shaft 6, lower coupling 7, inner rotor 10 and outer rotor 11 are coaxially and vertically arranged on frame base 14.

[0029] In this embodiment, the motor 3 is connected to an external power supply and a controller through wires for controlling the rotating speed of the motor 3; the torque sensor 5 is connected to an external power supply and a controller through wires for monitoring the torque of the inner rotor 10; the support column 13 is arranged around the central axis of the chassis 16, and the support column 13 is used to adjust the support of the chassis 16, wherein the support columns 13 are arranged at equal intervals; the inner rotor 10 adopts a detachable structure, which facilitates the convenient replacement of different inner rotor modules such as surface microstructure and smooth surface of the inner rotor 10 according to experimental requirements, the inner rotor 10 adopts switching of two ventilation modes of internal outward ventilation and bottom vertical upward ventilation, and can be replaced between different inner rotors with surface microstructure and smooth surface according to experimental requirements, so as to realize the research of the inner rotor surface microstructure and bubble composite drag reduction mechanism; by arranging the torque sensor 5, the torque sensor 5 is used to monitor the torque of the inner drive shaft 6, the inner drive shaft 6 rotates synchronously with the inner rotor 10, which facilitates the research on the change of the torque of the inner rotor 10 due to the surface microstructure of the inner rotor and the addition of bubbles, and has important significance for understanding and optimizing the fluid mechanics system involving bubbles; by arranging the support column 13, the support column 13 is located below the chassis 16, the chassis 16 is adjusted through the support column 13, and the output shaft of the motor 3, the upper coupling 4, the inner drive shaft 6, the lower coupling 7, the inner rotor 10 and the outer rotor 11 are coaxially and vertically arranged, thereby improving the working efficiency of the measuring device.

[0030] Working principle

[0031] In the present application, when in use, viscous fluid is arranged between the inner rotor 10 and the outer rotor 11, bubbles are delivered to the viscous fluid through the one-way ventilation valve 15, the motor 3 drives the inner rotor 10 to rotate, the inner rotor is replaced between different inner rotors with surface microstructure and smooth surface according to experimental requirements, which facilitates the research on the influence of bubbles on Taylor-Couette flow drag reduction measurement, the structure is simple, one motor 3 can meet the research requirements, the cost is low, the rotating speed of the motor 3 is controlled by the controller, the flow of the bubbles is controlled by the bubble generator, the control of different rotating speeds and gas flow can be realized; the torque sensor 5 is used to monitor the torque of the inner drive shaft 6, the inner drive shaft 6 rotates synchronously with the inner rotor 10, which facilitates the research on the change of the torque of the inner rotor 10 due to the addition of bubbles, and has important significance for understanding and optimizing the fluid mechanics system involving bubbles; the support column 13 is located below the chassis 16, the chassis 16 is adjusted through the support column 13, and the output shaft of the motor 3, the upper coupling 4, the inner drive shaft 6, the lower coupling 7, the inner rotor 10 and the outer rotor 11 are coaxially and vertically arranged, thereby improving the working efficiency of the measuring device; the convenient replacement of different inner rotors 10 with surface microstructure and smooth surface and the switching of two ventilation modes of internal outward ventilation and bottom vertical upward ventilation of the inner rotor 10 can be realized, thereby realizing the research of the inner rotor 10 surface microstructure and bubble composite drag reduction mechanism.

[0032] Any design that uses the technical solutions of the present application or is inspired by the technical solutions of the present application to achieve the above technical effects falls within the protection scope of the present application.

Claims

1. A device for measuring the drag reduction of a combination of microstructure on the surface of an object and bubbles based on Taylor-Couette flow, characterized in that: The application relates to a machine frame and a sealing structure thereof, which comprises a machine frame support column (1), a machine frame support plate (2), a motor (3), an upper coupling shaft (4), a torque sensor (5), an inner driving shaft (6), a lower coupling shaft (7), a mechanical seal (8), an upper end sealing connecting piece (9), an inner rotor (10), an outer rotor (11), a lower end sealing connecting piece (12), a support column (13), a machine frame base (14), a one-way air valve (15) and a bottom disc (16), one end of the machine frame support column (1) is arranged above the machine frame base (14); one end of the machine frame support plate (2) is arranged on the machine frame support column (1), and the machine frame support plate (2) is parallel to the machine frame base (14); the motor (3) is arranged above the machine frame support plate (2) and away from the machine frame support column (1), and the output shaft of the motor (3) penetrates to the lower side of the machine frame support plate (2); the inner driving shaft (6) is connected with the output shaft of the motor (3) through the upper coupling shaft (4); the torque sensor (5) is arranged on the outer side of the inner driving shaft (6), and the torque sensor (5) is slidably arranged on the inner driving shaft (6) and connected with the lower side of the machine frame support plate (2); the inner rotor (10) is coaxially arranged on the lower end of the inner driving shaft (6) through the lower coupling shaft (7); the bottom disc (16) is arranged above the machine frame base (14) through the support column (13); the outer rotor (11) is fixed above the bottom disc (16), the lower end of the outer rotor (11) is provided with the lower end sealing connecting piece (12), the upper end of the outer rotor (11) is provided with the upper end sealing connecting piece (9), and the outer rotor (11) is coaxially arranged outside the inner rotor (10); a ring gap is arranged between the inner rotor (10) and the outer rotor (11); the bottom disc (16) is provided with a plurality of one-way air valves (15) around a central shaft; the one-way air valves (15) are arranged in the ring gap; the mechanical seal (8) is arranged at the connection between the upper end sealing connecting piece (9) and the inner driving shaft (6).

2. The Taylor-Couette flow based object surface microstructure and bubble compound drag reduction measurement experimental device according to claim 1, wherein: A sliding bearing is arranged between the inner driving shaft (6) and the upper end sealing connecting piece (9); the upper end sealing connecting piece (9) and the outer rotor (11) adopt static sealing.

3. The Taylor-Couette flow based object surface microstructure and bubble compound drag reduction measurement experimental device according to claim 1, wherein: The upper end of the one-way air valve (15) and the lower end sealing connecting piece (12) adopt static sealing, and the one-way air valves (15) are arranged at equal intervals, the lower end of the one-way air valve (15) is connected with a bubble generator through a pipeline, and the one-way air valve (15) is used for preventing viscous fluid from flowing out of the outer rotor (11) through the one-way air valve (15).

4. The Taylor-Couette flow based object surface microstructure and bubble composite drag reduction measurement experimental apparatus of claim 1, wherein: The motor (3) output shaft, the upper coupling shaft (4), the inner driving shaft (6), the lower coupling shaft (7), the inner rotor (10) and the outer rotor (11) are coaxially and vertically arranged on the machine frame base (14).

5. The Taylor-Couette flow based object surface microstructure and bubble composite drag reduction measurement experimental apparatus of claim 1, wherein: The motor (3) is connected with an external power supply and a controller through wires and is used for controlling the rotating speed of the motor (3).

6. The Taylor-Couette flow based object surface microstructure and bubble composite drag reduction measurement experimental apparatus of claim 1, wherein: The torque sensor (5) is connected with an external power supply and a controller through wires and is used for monitoring the torque of the inner rotor (10).

7. The Taylor-Couette flow based object surface microstructure and bubble composite drag reduction measurement experimental apparatus of claim 1, wherein: The plurality of support columns (13) are arranged around the central axis of the base plate (16) and are used to adjust the support of the base plate (16), wherein the support columns (13) are arranged at equal intervals.

8. The Taylor-Couette flow based object surface microstructure and bubble composite drag reduction measurement experimental apparatus of claim 1, wherein: The inner rotor (10) is detachable, and different inner rotor modules such as surface microstructure and smooth surface can be conveniently replaced according to experimental requirements. The inner rotor (10) can switch between two ventilation modes, i.e., internal outward ventilation and bottom upright upward ventilation.

Images