Engine air inlet noise sound power test system and test method thereof

Abstract

The invention provides a test system of measuring engine air inlet noise sound power and a method thereof. In the invention, assembling of an installation support and a sound intensity probe is specially designed. The test system is constructed, and a scientific sound intensity and sound power algorithm is used to process a test signal. Through using a characteristic that a sound intensity vector carries out integral along a closed curved surface, an engine air inlet noise is completely isolated and extracted from an integral and complex noise field of an engine mathematically so as to be served as a reliable basis of evaluating the engine air inlet noise. Compared to sound power measurement by using an existing traditional sound pressure method, by using the method in the invention, a test result is irrelevant with a peripheral sound field, which means that there is no requirement to a sound field test environment and the test does not need to be performed in a specific acoustic environment, such as an anechoic chamber and a live room. Based on a mathematics principle, a characteristic of an air inlet noise source can be extracted from the complex engine noise field. Tool equipment, such as a big barrier board, an air inlet extension tube and the like, does not need to be designed and made.

Description

technical field [0001] The invention belongs to the technical field of engines, and in particular relates to an engine air inlet noise sound power testing system and a testing method thereof. Background technique [0002] At present, in the field of powertrain NVH, the method of measuring near-field sound pressure or covering with a large baffle and using an extension tube to lead out the intake air is used to evaluate the intake noise of the engine. The disadvantage is that the intake noise will be overwhelmed by other noises of the engine. The sound pressure measured in the near field also cannot reflect the pure intake noise. The second disadvantage is that the production of large baffles needs to be strictly consistent with the length, width and height specifications of the anechoic chamber, otherwise once there is a gap, low-frequency noise will have diffraction effects. The third disadvantage is that adding an intake extension tube will change the frequency characteri...

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Problems solved by technology

[0002] At present, in the field of powertrain NVH, the method of measuring near-field sound pressure or covering with a large baffle and using an extension tube to lead out the intake air is used to evaluate the intake noise of the engine. The disadvantage is that the intake noise will be overwhelmed by other noises of the engine. The sound pressure measured in the near field cannot reflect the pure intake noise

The second disadvantage is that the production of large baffles needs to be strictly consistent with the length, width and height specifications of the anechoic chamber, otherwise once there is a gap, low-frequency noise will have diffraction effects

The third disadvantage is that adding an intake extension tube will change the frequency characteristics of the intake noise

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