Method for calculating filling coefficient of sound field of fairing

Abstract

The invention discloses a method for calculating the filling coefficient of a sound field of a fairing.The method is based on the statistical energy analysis theory, a calculation model for the filling coefficient of the sound field is established, a modal number correction term in the calculation model is established according to geometrical boundary parameters of the fairing and a spacecraft, then the filling ratio eta of the sound field in the fairing is calculated, finally a corrected modal number and the filling ratio are substituted into the calculation model for the filling coefficient, the filling coefficient of the sound field of the fairing is obtained, and a spacecraft noise test condition is corrected through the filling coefficient, obtained through calculation, of the sound field of the fairing.Compared with a calculation method in NASA 7001 applied to current engineering, the method has the advantages that the physical significance of the parameters is definite, geometrical characteristics of the spacecraft can be considered, and correction precision is high.

Description

technical field [0001] The invention belongs to the technical field of acoustic vibration mechanical environment design of spacecraft, and in particular relates to a method for calculating the sound field filling factor of a fairing. Background technique [0002] During the launch process, the noise load in the fairing is an important mechanical environment experienced by the spacecraft, generally caused by the aerodynamic noise in the launch or return section, and it is a broadband random load with high-frequency energy dominant. In the actual flight process, the distribution of the sound pressure level in the fairing along the satellite axis is inconsistent, and it is very difficult to simulate the sound field characteristics in the real fairing in aerospace engineering. In order to facilitate implementation, the reverberation sound field is used in the project to simulate, and the reverberation noise test is used to assess the performance of the noise-sensitive large surf...

AI Technical Summary

Problems solved by technology

However, the model is relatively rough, and it is very difficult to determine the key parameter H (gap distance), and from the test results of NASALeRC (LewisResearchCenter) and GDSSD (GeneralDynamicsSpaceSystemsDivision) (specific references: WilliamOH, MarkEMandJeromeEM.NASALeRC'sAcousticFillEffectTestProgramandResults[C]. 65thShockandVibrationSymposium,SanDiego,California,1994.), compared with the experimental results, the current fill factor is undercorrected at low frequencies and overcorrected at high frequencies, such as figure 1 shown

In addition, the evaluation of the model is relatively rough, and it is not sensitive to the geometric configuration of the spacecraft.

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