Analysis of a new polymeric material for use in hermetic compressor discharge tube

Abstract

This work focuses on the determination of the properties of a new polymeric material to be used in the discharge tube of hermetic compressors. Therefore, the elastic modulus and loss factor were determined experimentally. The modulus of elasticity was obtained using the model fit method and the loss factor through the half power band. The model fit was based on the natural frequency of a cantilevered beam according to Timoshenko's theory. Also, the way in which the experiments were performed to obtain the frequency response curves of the polymeric samples was detailed. It was observed that the material has little variation in the modulus of elasticity with frequency, with average values ​​close to 0.7 GPa. A constant loss factor was obtained, with a value around 0.03. Then, these properties were used as input parameters for a finite element model, which allowed to calculate the vibratory power flow of the tube made with the new material. Finally, these results were compared with the energy flow of a typical discharge tube made of copper-plated steel. There was an average attenuation of approximately 16 dB in the frequency range up to 5 kHz, with the new material.