Abstract: The primary source of noise of a hermatic reciprocating compressor is the acoustic radiation from its housing. The acoustic radiation pressure of sheets is related to the vibration velocity amplitude, normal to the surface. To control such surface normal velocity, optimization of parameters such as plate thickness, plate stiffness and the reinforcement structure by ribs can be adopted. VTF (Vibration Transfer Function) simulation and analysis of the compressor housing is carried out to locate the spot with largest vibration on both upper and lower shells. An topological optimization of the compressor housing is conducted based on OptiStruct, and the optimal position, shape and size of the stiffener are derived, which can be referred to as the stiffener design guidance. According to modal and VTF simulation results of the optimized shell structure, the 1st-order and 2nd-order natural frequency increase by 8.5% and 3.0%, respectively. Meanwhile, the maximum normal vibration velocity of the response points on the shell decreases by 23.6%, lower than the target value. Through experimental verification of vibration and near-field acoustic pressure, the results show that vibration acceleration has reduced by 21.5% at the peak of 72 Hz, and the near-field acoustic pressure has dropped in the frequency bands below 2500 Hz and above 10000 Hz. The effectiveness of the morphological optimization simulation in improving the housing stiffness and reducing radiative noise based on OptiStruct has been verified.

Key words: Compressor, Acoustic radiation, Modal, VTF, Morphology optimization