Numerical Analysis Of Flow Characteristics And Impeller Parameters In Air Centrifugal Compressor Stage

Air centrifugal compressor is an important industrial equipment and plays an important role in lots of fields. For a long time, improving operational efficiency has been an important goal in air centrifugal compressor’s research. To achieve this goal, researchers need to know detail information of internal flow field in air centrifugal compressor. The information can be obtained by using Computational Fluid Dynamics method. It can effectively compensate for the lack of experiment. Numerical simulations are conducted to analyze the internal flow characteristics of a large chemical air centrifugal compressor stage by using commercial CFD software in this paper. The main work of this paper include four aspects.Firstly, the geometry model of the air centrifugal compressor stage is built by using Solidworks and the hexahedral grids are generated by using ICEM CFD. The gird model which meets accuracy requirements is obtained by conducting the grid independent test.Secondly, steady numerical simulations of stage of multiple flow rates are conducted based on MRF model and obtain the curves of pressure ratio and polytropic efficiency of the air centrifugal compressor stage. Flow characteristics of both impeller and stationary parts are analyzed. For impeller, details of pressure field, velocity field, streamline and jet wake structure are analyzed under different working conditions. For stationary parts, details of pressure field, velocity field, flow angle and mechanism of flow loss are analyzed.Thirdly, unsteady numerical simulations of rotating stall in the air centrifugal compressor stage is conducted based on throttle valve model. The law of rotating stall is researched through analyzing pressure field and velocity field.Finally, steady numerical simulations of stage of different blade numbers, blade thicknesses, blade exit angles and rotate speeds are conducted by using mixing-plane model and obtain the curves of flow characteristics. The influence of various parameters on the air centrifugal compressor stage performance is analyzed.