Wind tunnel nozzle, active noise reduction device and method based on porous media

A porous medium, active noise reduction technology, applied in measurement devices, aerodynamic tests, testing of machine/structural components, etc., can solve the problems of high machining accuracy, high construction and maintenance costs, and inability to effectively reduce noise radiation, etc. To achieve the effect of eliminating noise radiation, easy to control the suction capacity, and conducive to quality

Active Publication Date: 2021-01-19
HUAZHONG UNIV OF SCI & TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This solves the problem of reducing vortex waves, entropy waves, and acoustic disturbances on the wall of the Laval nozzle in the wind tunnel, complex adjustment structures, high processing precision, high construction and maintenance costs, and the inability to effectively reduce or eliminate supersonic and hypersonic wind tunnels. Technical Problems of Noise Radiation in Turbulent Boundary Layer on Nozzle Surface

Method used

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  • Wind tunnel nozzle, active noise reduction device and method based on porous media
  • Wind tunnel nozzle, active noise reduction device and method based on porous media
  • Wind tunnel nozzle, active noise reduction device and method based on porous media

Examples

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Effect test

Embodiment 1

[0048] This embodiment provides a wind tunnel nozzle based on porous media, such as figure 1 As shown, the wind tunnel nozzle includes a wind tunnel nozzle converging section 1 , a porous medium section 2 and a wind tunnel nozzle diverging section 3 .

[0049] The starting position of the porous medium section 2 is located at the transition point of the laminar flow-turbulent boundary layer in the diverging section 3 of the wind tunnel nozzle. The downstream area of ​​the tube is expanded; the porous material of the porous medium section 2 can be made of metal-based materials such as foamed aluminum and sintered copper to ensure that the wall surface of the porous treatment has sufficient strength; the porous medium section 2 and the wind tunnel nozzle expansion section 3 They can be bonded together with adhesives. The permeability of the porous medium section 2 is 0.01-10 Darcy.

[0050] When working, the high-pressure gas enters the wind tunnel nozzle from the tapering sec...

Embodiment 2

[0052] This embodiment provides a wind tunnel nozzle based on porous media, such as figure 2 As shown, the wind tunnel nozzle includes a wind tunnel nozzle converging section 1 , a porous medium section 2 and a wind tunnel nozzle diverging section 3 .

[0053] The porous medium 2 is arranged in multiple sections, and its starting position is located at the transition point of the laminar flow-turbulent boundary layer in the diverging section 3 of the wind tunnel nozzle. In order to further enhance the ability to control the suction gas in the boundary layer, the porous medium section 2 adopts a multi-section arrangement. figure 2 The medium porous medium section 2 is arranged in two sections, and the number of sections can be appropriately expanded during actual implementation.

[0054] In operation, the suction gas control method of the porous medium section 2 of the wind tunnel nozzle provided in this embodiment is consistent with that in Embodiment 1.

Embodiment 3

[0056] This embodiment provides an active noise reduction device based on porous media, which is a hypersonic wind tunnel wall active noise reduction device based on porous media suction flow control, such as image 3 As shown, it includes the wind tunnel nozzle of Embodiment 1 and the side wall 6 of the suction chamber.

[0057] The side wall of the suction chamber surrounds the outer circumference of the entire wind tunnel nozzle wall, and forms a suction chamber 4 with the wall of the wind tunnel nozzle. The side wall 6 of the suction chamber is provided with a suction outlet 5, and the suction chamber 4 Except the suction air outlet 5, other parts of the cavity are sealed. The permeability of the porous medium section 2 is 0.01-10 Darcy.

[0058] When working, the high-pressure gas enters the wind tunnel nozzle from the tapering section 1 of the wind tunnel nozzle and starts to accelerate, and reaches the speed of sound at the throat of the nozzle, and then further accele...

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Abstract

The invention discloses a wind tunnel nozzle based on a porous medium, and an active noise reduction device and method, and belongs to the technical field of hypersonic wind tunnel low-turbulivity andquiet wind tunnel design. The wind tunnel nozzle comprises a wind tunnel nozzle convergent section, a wind tunnel nozzle divergent section and a porous medium section, wherein the porous medium section is arranged in a single-section or multi-section manner, is positioned at a turning point of a laminar flow-turbulent boundary layer of the wind tunnel nozzle divergent section, and forms the windtunnel nozzle with a Laval nozzle structure together with the wind tunnel nozzle convergent section and the wind tunnel nozzle divergent section. The invention further provides the corresponding active noise reduction device and method. The turbulence kinetic energy distribution in the boundary layer is reduced through a wall surface suction air flow control means; the noise radiation of the turbulent boundary layer can be indirectly reduced to a great extent; the construction and maintenance cost of a supersonic / hypersonic quiet wind tunnel is reduced; and meanwhile the free incoming flow quality of the wind tunnel is greatly improved.

Description

technical field [0001] The invention belongs to the technical field of hypersonic wind tunnel low turbulence and static wind tunnel design, and more specifically relates to a porous medium-based wind tunnel nozzle, active noise reduction device and method. Background technique [0002] As the commanding heights of aerospace research in the 21st century, supersonic and hypersonic vehicles and related technologies have always been the focus of development by major countries in the world. The traditional methods of studying supersonic and hypersonic flow phenomena mainly include numerical simulation, flight test and ground test. Due to the special flow conditions under high-speed flow, such as real gas effects, high-temperature non-equilibrium gas effects, etc., the existing numerical calculation models are not applicable. Therefore, experimental measurement has become the main means of studying supersonic and hypersonic flow. Among them, the flight test simulates the real fl...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): G01M9/04
CPCG01M9/04
Inventor 吴杰赵家权余涛张威
Owner HUAZHONG UNIV OF SCI & TECH
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