Radiation acoustic power calculation method based on modal partial coupling hypothesis

A radiated sound, modal technology, applied in complex mathematical operations, vibration measurement in fluids, measurement of vibration, etc., can solve the problems of noise optimization failure, radiated noise does not fall but rises, and achieves the effect of eliminating theoretical energy errors.

Inactive Publication Date: 2019-08-23
ZHEJIANG UNIV
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Problems solved by technology

This means that when calculating the radiated sound power from the modal aspect, there is an unknown coupling situation between the modes, and the peak value of the actual radiated sound power may not be dominated by the constrained mode corresponding to the frequency, so that based on the modal tracking The noise optimization of the method fails, and even leads to the result that the radiation noise does not decrease but rises after optimization

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  • Radiation acoustic power calculation method based on modal partial coupling hypothesis
  • Radiation acoustic power calculation method based on modal partial coupling hypothesis
  • Radiation acoustic power calculation method based on modal partial coupling hypothesis

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Embodiment Construction

[0053] The present invention will be further described below in conjunction with the accompanying drawings.

[0054] A method for calculating the sound power of radiated noise based on the assumption of modal partial coupling proposed by the present invention, such as figure 1 shown, including the following steps:

[0055] Step 1. Solving the modal equation in the time domain, the process is as follows:

[0056] Construct a system of second-order ordinary differential equations for response analysis:

[0057]

[0058] x=Φq

[0059] Among them, M, C, K are structural mass matrix, damping matrix and stiffness matrix respectively, x=[x 1 x 2 … x n ] T is the displacement response matrix, F is the forced load matrix, t is the time, Φ is the mode matrix, q=[q 1 q 2 … q n ] T is the mode coordinate vector, and n is the truncated mode.

[0060] deformation available

[0061]

[0062] Φ T MΦ=diag[M 1 m 2 …M n ]

[0063] Φ T CΦ=diag[C 1 C 2 …C n ]

...

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Abstract

The invention discloses a radiation acoustic power calculation method based on a modal partial coupling hypothesis. The method mainly comprises the steps of structure modal calculation, structure vibration response solving, vibration acceleration mapping to a surface air layer and radiation acoustic power calculation based on the modal partial coupling hypothesis. Compared with a radiation acoustic power calculation method based on a modal uncoupling hypothesis and a modal coupling hypothesis, the radiation acoustic power calculation method based on the modal partial coupling meets the requirement for energy conservation, achieves complementation of the uncoupling hypothesis and the coupling hypothesis, and achieves the purpose of eliminating theoretical energy errors.

Description

technical field [0001] The invention relates to a calculation method of structural radiated sound power, in particular to a calculation method of radiated sound power based on the assumption of modal partial coupling. Background technique [0002] With the development of computer-aided design technology (CAE), it has become possible to optimize the structure-acoustic-vibration and NVH performance at the beginning of product manufacturing. Among them, the modal tracking method is based on the calculation process of the modal-vibration-noise method to optimize the structure radiation noise. Due to its high efficiency, it has been widely used in industry. [0003] According to the orthogonality of the modes, it is a reasonable linear process to use the mode superposition method to solve the vibration response of the structure. However, according to the acoustic theory, calculating the radiated sound power through the vibration response is a nonlinear process. This means that ...

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Application Information

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IPC IPC(8): G06F17/13G01H3/10
CPCG01H3/10G06F17/13
Inventor 郑旭贾梓镔刘瑞骏郝志勇
Owner ZHEJIANG UNIV
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