Fluid - structure interaction analyze for the centrifugal compressor 3d impellers

Abstract

The article deals with the issues of the 3D impellers strength analysis for the different centrifugal compressors. Two air compressors are considered, the first for General industrial use, the second for turbocharging the internal combustion engine. The third compressor is designed for the turboexpander unit that operating at high pressure medium. The materials of the impellers were steel, titanium and aluminum alloys. The expediency of using the Fluid-Structure Interaction approach for the strength analysis is considered for these compressors. With the FSI approach, a coupled CFD-FEA solution is performed. Gas-dynamic forces from the medium pressure are taken into account in the impeller strength or vibration analysis. The Ansys package is selected as the program for analysis. CFD models are built and configured in the Ansys CFX. The FEA solution carried out in the Ansys Static structural. The results of strength analysis are compared with and without pressure forces for all impellers. As a result, there were no significant differences in the two solutions for the air compressors. However, for high-pressure compressors, the results of the coupled solution showed the need to take into account the CFD solution. Based on the obtained data, a graph of the reliability coefficient dependence on the increase in the suction pressure in the range from 1 to 100 bar is plotted.