Prediction of Structural Acoustic Radiation for Compressor Considering Airflow Pulsed Load

摘要

A coupled vibro-acoustic of a compressor modeling process was demonstrated for predicting the acoustic radiation from a vibrating compressor structure based on dynamic response data. FEM based modal analysis of the compressor was performed and the result was compared with experimental data, for the purpose of validating the FE model. Modal based force response analysis was conducted to calculate the compressor's surface vibration velocity on radiating structure, using the load which caused by mechanical excitation as input data. In addition, due to the coolant had oscillating gas pressure, the gas pulsed load was also considered during the dynamic response analysis. The surface vibration velocity solution of the compressor provided the necessary boundary condition input into a finite element/boundary element acoustic code for predicting acoustic radiation. A hemispherical field point model was built according to ISO 3744:1994 to evaluate the noise radiated during the compressor run-up in the frequency domain. With application of the field response analysis, the radiation power, the field point sound pressure level was calculated. For purpose of noise and vibration reduction, some researches focused on parameters that affected the compressor noise radiation, such as compressor housing thickness and chilled storage housing thickness, were carried out. Sound power measurement was performed in semi-anechoic chamber for simulation verification. Calculated and analytical results were generalized for further noise and vibration reduction research process.