Research on membrane stress of diaphragm compressors based on bidirectional fluid-structure interaction

Abstract Currently, in the analysis of the stress distribution on the diaphragm of a diaphragm compressor, a static analysis method is employed, assuming that the pressure on the diaphragm is uniformly distributed, which does not reflect reality. To investigate the impact of pressure distribution on diaphragm stress, a bidirectional fluid-structure interaction method is used, combined with User-Defined Functions (UDF) and dynamic mesh techniques. This method establishes a simulation model that fully simulates the compression, discharge, expansion, and suction phases of the diaphragm compressor. The pressures on the upper and lower surfaces of the diaphragm are applied to determine the maximum stress, which is then compared with the stress under uniform pressure. The results show that the pressure distribution on the diaphragm is uneven, and the maximum stress of the diaphragm calculated by the bidirectional fluid-structure interaction method is 12.73 MPa higher than that of the static analysis method. The uniform distribution pressure is used to analyze the strength and life reliability of the diaphragm, which is not high.