Low-noise hydrodynamic noise rotation test device in still water

Abstract

The invention provides a static water low-noise hydrodynamic noise rotation test device 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, and a sectional type variable-length suspender is used for connecting a test model and the rotating arm. The stepping motor and the speed reducer are installed on the supporting frame through the double-layer vibration isolation device, and the stepping motor and the speed reducer can push the rotating arm to rotate so as to drive the test model to do large-diameter rotary motion. The test device disclosed by the invention can be used for carrying out a rotation test in a relatively large water pool or a lake or on the sea, and controlling sound radiation of mechanical vibration noise to underwater at the same time, so that background noise is effectively reduced, and measurement of flow-induced vibration noise of a large-scale model is realized.

Description

Technical Field

[0001] The invention belongs to the technical field of underwater vehicle hydrodynamic noise control, and in particular relates to a low-noise underwater vehicle rotation test device in still water. Background Art

[0002] In order to study the vibration, pulsating pressure, self-noise and radiation noise problems caused by fluid excitation when underwater vehicles are moving, the industry has proposed to conduct underwater unpowered surfacing tests on lakes or seas in order to eliminate the noise of the power system and propulsion system of general test platforms.

[0003] However, existing floating test platforms all need to be tested on lakes or at sea, which has a long test cycle, high cost and poor repeatability. It is difficult to avoid the mechanical noise of the towing system when conducting towing tests in laboratory water pools. When conducting tests in water tunnels, it is difficult to conduct large-scale model tests due to space limitations, and the acoustic cavity is too small and the applicable lower limit frequency is too high to meet the engineering needs for direct noise measurement. In addition, during the water tunnel experiment, the object is fixed and the water is in a non-static state. For working conditions that are sensitive to fluid flow, there is a big difference from the actual requirements that the object is moving and the water is static. Summary of the invention

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

[0005] To achieve the above-mentioned purpose, the present invention provides a low-noise hydrodynamic noise rotation test device in still water, comprising a stepper motor and a reducer located below the stepper motor, the rotating shaft of the rotating arm is connected to the reducer through a vibration reduction device, and the segmented variable length suspension rod is used to connect the test model and the rotating arm. The stepper motor and the reducer are installed on a support frame through a double-layer vibration isolation device. The stepper motor and the reducer can drive the rotating arm to rotate, thereby driving the test model to perform a large-diameter rotational motion.

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

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

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

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

[0010] Furthermore, a control console is provided, which is used to receive relevant test data of the vibration, pulsating pressure, acoustic and other measuring equipment; at the same time, the control console can control the rotation speed of the stepper motor, and thus control the rotation speed of the rotating arm during the test.

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

[0012] Furthermore, a balancing weight is installed at the opposite end where the rotating arm is connected to the segmented variable-length boom.

[0013] Furthermore, the support rod is used for a surface vessel and a support frame on a lake or sea.

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

[0015] The test device of the present invention can carry out rotation tests in a larger water pool or in a lake or sea, while controlling the acoustic radiation of mechanical vibration noise to the underwater, effectively reducing background noise, so as to realize the measurement of flow-induced vibration noise of a large-scale model. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Schematic diagram of the first embodiment of the test device of the present invention

[0017] Figure 2 Schematic diagram of the second embodiment of the test device of the present invention

[0018] Explanation of the reference numerals: 1-cross-pool support frame, 1′-surface vessel and support frame, 2-stepping motor, 3-reducer, 4-elastic coupling, 5-thrust bearing, 6-lower bearing, 7-balance weight, 8-upper shock absorber, 9-middle mass block, 10-lower shock absorber, 11-rotating arm, 12-segmented variable-length boom, 13-test model, 14-shock absorber, 15-control console, 16-vibration, pulsating pressure, acoustic and other measuring equipment. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments.

[0020] like Figure 1 As shown, it 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 installed 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 suspension rod 12 is connected to the rotating arm 11, and the other end is connected to the test model 13, so that the stepper motor 2 and the reducer 3 can drive the rotation of the rotating arm, and then drive the test model to move.

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

[0022] The thrust bearing 5 and the lower bearing 6 are fixedly connected to the cross-pool support frame 1, and 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 jointly 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 an elastic coupling 4.

[0023] The vibration absorber 14 is installed on the end of the rotating arm 11 away from the motor to reduce the transmission of the motor vibration. One end of the segmented variable length suspension rod 12 is connected to the rotating arm 11 through the vibration absorber 14, and the other end is connected to the test model 13. Vibration, pulsating pressure, acoustic and other measuring equipment 16 are arranged inside the test model 13, on the surface and at a certain distance from the pool to obtain data for vibration and noise research.

[0024] The double-layer vibration isolation device, the elastic coupling 4 and the shock absorber 11 are all vibration reduction devices of the test device, and their functions are to isolate or reduce the transmission of the vibration noise of the stepper motor 2 and the reducer 3 to the test model, prevent the vibration generated by the stepper motor and the reducer during work from interfering with the test process, and make the underwater radiation noise background well controlled.

[0025] The control console 15 is a control terminal for receiving relevant test data of the measuring device 16 ; meanwhile, the control console 15 can control the rotation speed of the stepper motor 2 , and further control the rotation speed of the rotating arm 11 during the test.

[0026] A balancing weight 7 is installed at the opposite end where the rotating arm 11 is connected to the segmented variable length boom 12, which is used to prevent the rotating arm 11 from becoming unstable due to unbalanced counterweights on both sides of the rotating arm during rotation, thereby making the movement of the rotating arm 11 more stable.

[0027] As the second embodiment of the present invention, unlike the first embodiment in which the test device is suitable for use in a pool, the second embodiment is a test device for use on a lake or at sea, such as Figure 2 As shown, the overall structure of the experimental device needs to be installed on a surface ship and a support frame 1', so that the device can be used for field tests on a lake or at sea. The remaining structure is no different from the first embodiment of the present invention and will not be described again here.

[0028] Therefore, the overall experimental process of the present invention is that under the control of the control console 15, the stepper motor 2 rotates at a set speed, driving the reducer 3 to start working, and further drives the rotating arm 11 and the segmented variable length suspension rod 12 to rotate through the kinetic energy transmission of the elastic coupling 4, so as to make the test model 13 perform a large-diameter rotational motion in still water, and through the vibration, pulsating pressure, acoustic and other measuring sensors and measuring equipment installed inside and outside the test model 13, full-band measurement of near-field and far-field vibration parameters under different Reynolds numbers is achieved.

[0029] Preferably, the sectioned variable-length boom 12 of the present invention is streamlined below the water surface line 17. The streamlined shape can reduce the noise generated by the friction between the boom and the water flow during rotation.

[0030] As a further improvement of the present invention, the segmented variable length suspension rod 12 is designed to be L-shaped so that the test model 13 is away from the vertical section of the suspension rod, further reducing the transmission of vibration to obtain a quieter background noise.

[0031] The low-noise hydrodynamic noise test device of the present invention can realize hydrodynamic noise tests of models with different speeds, different turning radii and different depths by changing the stepper motor speed, the length of the rotating arm and the length of the boom. And by realizing it in a pool or open water area of ​​a lake or sea, it can test a larger-scale model and obtain vibration noise data of the full frequency band.

[0032] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

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), a rotating shaft of a rotating arm (11) connected to the reducer (3) via a vibration reduction device, a segmented variable-length suspension rod (12) used to connect a test model (13) and the rotating arm (11), characterized in that: The stepper motor (2) and the reducer (3) are installed on the support frame (1, 1′) via a double-layer vibration isolation device. The stepper motor (2) and the reducer (3) can drive the rotating arm (11) to rotate, thereby driving the test model (13) to perform large-diameter rotary motion.

2. The low-noise hydrodynamic noise rotation test device in still water according to claim 1, characterized in that: The vibration damping device is an elastic coupling (3), and the double-layer vibration isolation device is composed of an upper vibration damper (8), an intermediate mass block (9) and a lower vibration damper (10). The double-layer vibration isolation device and the elastic coupling (3) are used to isolate the vibration noise of the stepping motor (2) and the reducer (3).

3. The low-noise hydrodynamic noise rotation test device in still water according to claim 1, characterized in that: A vibration damper (14) is also provided on the side of the rotating arm (11) away from the stepping motor (2), and the vibration damper (14) is used to further attenuate the transmission of vibration noise to the test device (13).

4. The low-noise hydrodynamic noise rotation test device in still water according to claim 2, characterized in that: The thrust bearing (5) and the lower bearing (6) are installed on the support frame (1, 1'), and the rotating shaft part of the rotating arm (11) is installed through the thrust bearing (5) and the lower bearing (6).

5. The low-noise hydrodynamic noise rotation test device in still water according to claim 1, characterized in that: Vibration, pulsating pressure, acoustic and other measuring equipment (16) are arranged inside, on the surface and at a certain distance from the water pool of the test model (13).

6. The low-noise hydrodynamic noise rotation test device in still water according to claim 5, characterized in that: A control console (15) is also provided, and the control console (15) is used to receive relevant test data of the vibration, pulsating pressure, acoustic and other measuring equipment (16); at the same time, the control console (15) can control the rotation speed of the stepper motor (2), thereby controlling the rotation speed of the rotating arm (11) during the test.

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

8. The low-noise hydrodynamic noise rotation test device in still water according to claim 1, characterized in that: A balancing weight (7) is installed at the opposite end where the rotating arm (11) is connected to the segmented variable-length suspension rod (12).

9. The low-noise hydrodynamic noise rotation test device in still water according to claim 1, characterized in that: The support rod is used for a surface ship and a support frame (1') on a lake or sea.

10. The low-noise hydrodynamic noise rotation test device in still water according to any one of claims 1 to 9, characterized in that: The section of the segmented variable length boom (12) below the water surface line (17) is preferably streamlined; the segmented variable length boom (12) is preferably L-shaped so that the test model (13) is away from the vertical section of the boom to reduce the transmission of vibration noise.

Images