Standing wave tube acoustic testing system based on double-sound-source method
An acoustic test and standing wave tube technology, applied in the aviation field, can solve the problems of not being able to simulate the cruising differential pressure state and not considering the differential pressure environment
Active Publication Date: 2021-06-04
COMAC +1
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Problems solved by technology
At present, the impedance tube method test does not consider the pressure difference environment, and cannot simulate the cruise pressure difference state
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[0051] Specific implementations of the present invention will be described below. It should be noted that in the process of specific descriptions of these implementations, for the sake of concise description, it is impossible for this specification to describe all the features of the actual implementations in detail. It should be understood that, in the actual implementation process of any embodiment, just like in the process of any engineering project or design project, in order to achieve the developer's specific goals and to meet system-related or business-related constraints, Often a variety of specific decisions are made, and this can vary from one implementation to another. In addition, it will be appreciated that while such development efforts may be complex and lengthy, the technology disclosed in this disclosure will be Some design, manufacturing or production changes based on the content are just conventional technical means, and should not be interpreted as insuffic...
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Abstract
The invention relates to a standing wave tube acoustic testing system based on a double-sound-source method. The system comprises a pressure-resistant pipe section, a normal-pressure pipe section, a test piece mounting pipe section, a test piece clamp, a vacuum pump, a multi-channel input / output module, two groups of microphones and two sound sources, a sound source is mounted at one end of the pressure-resistant pipe section; another sound source is mounted at one end of the normal-pressure pipe section; the test piece mounting pipe section is connected between the pressure-resistant pipe section and the normal-pressure pipe section; the test piece clamp is arranged in the test piece mounting pipe section and is used for fixing a test piece; the vacuum pump is connected to the pressure-resistant pipe section and is used for forming negative pressure in the pressure-resistant pipe section; the multi-channel input and output module is used for collecting signals of the two groups of microphones and controlling input signals of the two sound sources; and the two groups of microphones are used for respectively collecting the sound pressure in the pressure-resistant pipe section and the sound pressure in the normal-pressure pipe section. According to the technical scheme, the beneficial technical effects are that the internal and external pressure difference environment in a cruise state can be simulated aiming at a small sample, and the middle-low frequency bidirectional normal incidence sound reduction index and the sound absorption coefficient are tested.
Description
technical field [0001] The invention relates to the field of aviation technology, in particular to an acoustic testing system for a standing wave tube with a dual sound source method. Background technique [0002] For testing the material and structural acoustic properties of small samples, the commonly used method is the impedance tube method. In order to ensure the test accuracy, the impedance tube method requires that the end of the tube must be equipped with a sound-absorbing wedge or load with high sound-absorbing performance. The sound coefficient is required to be greater than 0.99. In practice, good sound-absorbing ends are generally achieved by using long exhaust pipes, high-absorbent materials, or horn-shaped pipes. However, no matter which method is used to establish the sound-absorbing end, it is difficult to achieve complete noise elimination, especially under the excitation of low-frequency sound waves, the sound absorption coefficient of the sound-absorbing e...
Claims
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IPC IPC(8): G01N29/26G01N29/11
CPCG01N29/26G01N29/11G01N2291/015G01N2291/023
Inventor 胡莹李晨曦赵华勇冉勍张鹏飞
Owner COMAC