A low-noise hydrodynamic noise rotating test device in still water

Abstract

The application provides a low-noise hydrodynamic noise rotating test device in static water, which comprises a stepping motor and a speed reducer located below the stepping motor, a rotating shaft of a rotating arm is connected with the speed reducer through a damping device, a segmented variable-length boom is used for connecting a test model and the rotating arm, the stepping motor and the speed reducer are installed on a support frame through double-layer vibration isolation devices, the stepping motor and the speed reducer can drive the rotating arm to rotate, and then drive the test model to make large-diameter rotary motion. The test device can perform rotating test in a large pool or on a lake or sea, simultaneously control the sound radiation of mechanical vibration noise to the water, effectively reduce the background noise, and realize the measurement of flow-induced vibration noise of a large-scale model.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of underwater vehicle hydrodynamic noise control, and particularly relates to a low-noise underwater vehicle rotating test device in still water. BACKGROUND

[0002] In order to study the vibration, pulsating pressure, self-noise and radiation noise problems caused by fluid excitation when the underwater vehicle moves, it has been proposed in the industry to conduct underwater unpowered floating tests on lakes or seas so as to eliminate the noise of the power system and the propulsion system of the general test platform.

[0003] However, the existing floating test platforms all need to be tested on lakes or seas, and the test cycle is long, the cost is high, and the repeatability is poor. If a towing test is conducted in a test room pool, it is difficult to avoid the mechanical noise of the towing system. If a test is conducted in a water tunnel, it is difficult to conduct a large-scale model test due to space limitations, and the lower limit frequency is too high due to the small acoustic cavity, which is difficult to meet the demand of direct noise measurement in engineering; in addition, during the water tunnel test, the object is fixed and the water is in a non-stationary state, which is quite different from the actual requirement that the water is stationary when the object moves in the working condition sensitive to fluid flow. SUMMARY

[0004] Based on the above shortcomings of the prior art, the present application provides a low-noise rotating test device for hydrodynamic noise test in still water, which can adapt to large-scale underwater vehicles or local models, and can be used as a test verification platform for flow-induced vibration, pulsating pressure, near-field and far-field noise mechanism and control effect of underwater moving structures.

[0005] To achieve the above-mentioned purpose, the present application provides a low-noise hydrodynamic noise rotating test device in still water, which comprises a stepping motor and a speed reducer located below the stepping motor, the rotating shaft of a rotating arm is connected with the speed reducer through a damping device, a segmented variable-length boom is used to connect the test model and the rotating arm, the stepping motor and the speed reducer are installed on a support frame through a double-layer vibration isolation device, the stepping motor and the speed reducer can drive the rotating arm to rotate, and in turn drive the test model to make large-diameter rotary motion.

[0006] Further, the damping device is an elastic coupling, and the double-layer vibration isolation device is composed of an upper damper, an intermediate mass block and a lower damper, and the double-layer vibration isolation device and the elastic coupling are used to isolate the vibration noise of the stepping motor and the speed reducer.

[0007] Further, a damper is arranged on the side of the rotating arm away from the stepping motor, and the damper is used to further attenuate the transmission of vibration noise to the test device.

[0008] Further, the thrust bearing and the lower bearing are installed on the support frame, and the rotating shaft part of the rotating arm penetrates through the thrust bearing and the lower bearing.

[0009] Further, vibration, pulsating pressure, acoustic and other measuring devices are arranged at a certain distance from the inside, surface and pool of the test model.

[0010] Further, a control console is also provided, which is used to receive the relevant test data of the vibration, pulsating pressure, acoustic and other measuring devices; at the same time, the control console can control the rotating speed of the stepping motor, thereby controlling the rotating speed of the rotating arm during the test process.

[0011] Still further, the support rod is a cross-pool support frame used in the pool.

[0012] Still further, a counterweight is installed at the opposite end of the rotating arm connected with the segmented variable-length boom.

[0013] Still further, the support rod is a water surface ship and support frame used on the lake or sea.

[0014] Still further, the segmented variable-length boom is preferably streamlined below the water surface line; the segmented variable-length boom is preferably L-shaped, so that the test model is far away from the vertical section of the boom, and the transmission of vibration noise is reduced.

[0015] The test device of the present application can perform rotating test in a larger pool or on the lake or sea, while controlling the sound radiation of mechanical vibration noise to the water, effectively reducing the background noise, so as to realize the measurement of the flow-induced vibration noise of the large-scale model. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 The first embodiment of the test device of the present application is shown in the figure

[0017] Figure 2 The second embodiment of the test device of the present application is shown in the figure

[0018] Explanation of reference numerals: 1-cross-pool support frame, 1'-water surface ship and support frame, 2-stepping motor, 3-reducer, 4-elastic coupling, 5-thrust bearing, 6-lower bearing, 7-counterweight, 8-upper layer damper, 9-intermediate mass block, 10-lower layer damper, 11-rotating arm, 12-segmented variable-length boom, 13-test model, 14-damper, 15-control console, 16-vibration, pulsating pressure and acoustic and other measuring devices. DETAILED DESCRIPTION

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments.

[0020] like Figure 1 As shown, this is a schematic diagram of the overall structure of the first embodiment of the present invention. The stepper motor 2 and the reducer 3 are mounted on the cross-pool support frame 1. The reducer 3 is connected to the shaft of the rotating arm 11 through the elastic coupling 3. One end of the segmented variable length rod 12 is connected to the rotating arm 11, and the other end is connected to the test model 13. Thus, the stepper motor 2 and the reducer 3 can drive the rotation of the rotating arm, thereby driving the test model to move.

[0021] Specifically, the stepper motor 2 and the reducer 3 are mounted on the cross-pool support frame 1 via a double-layer vibration isolation device. The double-layer vibration isolation device consists of an upper vibration damper 8, a middle mass block 9, and a lower vibration damper 9. The upper vibration damper 8 is located at the top and is in contact with the reducer 3; the lower vibration damper 10 is connected to the cross-pool support frame 1 at the bottom; and the middle mass block 9 is installed between the upper vibration damper 8 and the lower vibration damper 10.

[0022] The thrust bearing 5 and the lower bearing 6 are fixedly connected to the cross pool support frame 1. The rotating shaft of the rotating arm 11 is installed through the thrust bearing 5 and the lower bearing 6. The thrust bearing 5 and the lower bearing 6 together fix the rotating arm 11 and can provide support when the rotating arm 11 rotates. The reducer 3 is connected to the rotating shaft of the rotating arm 11 through the flexible coupling 4.

[0023] Vibration damper 14 is installed on the end of the rotating arm 11 away from the motor to reduce the transmission of motor vibration. One end of the segmented variable length boom 12 is connected to the rotating arm 11 via vibration damper 14, and the other end is connected to the test model 13. Vibration, pulsating pressure, and acoustic measuring devices 16 are arranged inside the test model 13, on its surface, and at certain distances from the water tank to obtain data for vibration and noise research.

[0024] The double-layer vibration isolation device, the flexible coupling 4, and the vibration damper 11 are all vibration damping devices of this test apparatus. Their functions are to isolate or reduce the transmission of vibration noise from the stepper motor 2 and the reducer 3 to the test model, prevent the vibration generated by the stepper motor and reducer during operation from interfering with the test process, and ensure that the underwater radiated noise background is well controlled.

[0025] The console 15 is a control terminal for receiving relevant test data of the measuring device 16; meanwhile, the console 15 can control the rotating speed of the stepping motor 2, thereby controlling the rotating speed of the rotating arm 11 in the test process.

[0026] A counterweight 7 is installed at the opposite end of the rotating arm 11 connected with the sectional variable-length boom 12, for preventing instability of the rotating arm 11 in the rotating process due to the imbalance of the counterweights on both sides of the rotating arm, and for making the rotating arm 11 move more stably.

[0027] As the second embodiment of the present application, unlike the test device suitable for use in a pool in the first embodiment, the second embodiment is a test device for use on a lake or sea, as shown in the figure, the overall structure of the test device needs to be installed on a water surface ship and a support frame 1', and then the device can be used for field test on a lake or sea, and the rest of the structure is not different from the first embodiment of the present application, and will not be described here. Figure 2

[0028] Therefore, the overall process of the test of the present application is that, under the control of the console 15, the stepping motor 2 rotates at a specified rotating speed, drives the speed reducer 3 to start working, further drives the rotating arm 11 and the sectional variable-length boom 12 to rotate through the kinetic energy transmission of the elastic coupling 4, and then makes the test model 13 make large-diameter rotating motion in the still water, and realizes full-band measurement of near-field and far-field vibration parameters under different Reynolds numbers through the vibration, pulsating pressure, acoustic and other measuring sensors and measuring devices installed inside and outside the test model 13.

[0029] As a preferred embodiment, the sectional variable-length boom 12 of the present application is streamline below the water surface line 17, and through the streamline shape, noise generated by the friction between the boom and the water flow in the rotating process can be reduced.

[0030] As a further improvement of the present application, the sectional variable-length boom 12 is designed as an L shape, so that the test model 13 is far away from the vertical section of the boom, further reducing the transmission of vibration, to obtain a more quiet background noise.

[0031] The low-noise hydrodynamic noise test device of the present application can realize hydrodynamic noise test of models with different speeds, different rotating radii and different depths by changing the rotating speed of the stepping motor, the length of the rotating arm and the length of the boom. And through the implementation in the pool or the open water area of the lake or sea, a larger scale model can be tested and full-band vibration noise data can be obtained.

[0032] ​The above merely provides the preferred embodiments of the present application, and is not used to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the principles and technical scope of the present application shall fall into the scope of the present application.

Claims

1. A low-noise hydrodynamic noise rotation test device in still water, comprising a stepper motor (2) and a reducer (3) located below the stepper motor (2), the rotating shaft of the rotating arm (11) being connected to the reducer (3) via a vibration damping device, and a segmented variable-length boom (12) for connecting the test model (13) and the rotating arm (11), characterized in that: The stepper motor (2) and reducer (3) are mounted on the support frame via a double-layer vibration isolation device. The stepper motor (2) and reducer (3) can drive the rotating arm (11) to rotate, thereby driving the test model (13) to perform large-diameter rotational motion. The vibration isolation device is an elastic coupling (4). The double-layer vibration isolation device consists of an upper vibration damper (8), a middle mass block (9), and a lower vibration damper (10). The double-layer vibration isolation device and the elastic coupling (4) are used to isolate the vibration noise of the stepper motor (2) and reducer (3). When the rotating arm (11) is away from the stepper motor (2), the vibration noise is generated by the stepper motor (2) and reducer (3). A vibration damper (14) is also provided on one side of the motor (2). The vibration damper (14) is used to further attenuate the transmission of vibration noise to the test model (13). The thrust bearing (5) and the lower bearing (6) are mounted on the support frame. The rotating shaft of the rotating arm (11) is installed through the thrust bearing (5) and the lower bearing (6). The section of the segmented variable length boom (12) below the water surface line (17) is streamlined. The segmented variable length boom (12) is L-shaped so that the test model (13) is far away from the vertical section of the boom, thereby reducing the transmission of vibration noise.

2. The low-noise hydrodynamic noise rotation test device in still water according to claim 1, characterized in that, Vibration, pulsating pressure, and acoustic measurement devices (16) are arranged inside the test model (13), on its surface, and at a certain distance from the water tank.

3. The low-noise hydrodynamic noise rotation test device in still water according to claim 2, characterized in that, A control console (15) is also provided, which is used to receive relevant test data from the vibration, pulsating pressure, and acoustic measurement equipment (16); at the same time, the control console (15) can control the speed of the stepper motor (2), thereby controlling the rotation speed of the rotating arm (11) during the test.

4. The low-noise hydrodynamic noise rotation test device in still water according to claim 1, characterized in that, The support frame is a cross-pool support frame (1) used in a water tank.

5. The low-noise hydrodynamic noise rotation test device in still water according to claim 1, characterized in that, A counterweight (7) is installed at the opposite end of the connection between the rotating arm (11) and the segmented variable length boom (12).

6. The low-noise hydrodynamic noise rotation test device in still water according to claim 1, characterized in that, The support frame is for a surface vessel and support frame used on a lake or at sea (1′).

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