Simulating the flow field in a rear stage of a multistage axial flow compressor

The deterministic stress model proposed by Adamczyk has been proven to be a more rigorous model than mixing plane model in the flow prediction of multistage turbomachinery using steady state methods. In the deterministic stress model, a practical way of calculating the deterministic stresses is to apply overlapped solution domains. In this paper, a modification to the deterministic stress model is made, in which the body force of the flow is simulated through pressure gradient and centrifugal force and the blade blockage effect is approximated through mass continuity equation. A pressure correction method with the standard k-epsilon: turbulence model is employed for the solution of Navier-Stokes equations. Two computational investigations for the third stage of the Cranfield University Low Speed Research Compressor (LSRC), one with the deterministic stress model and the other with the mixing plane model, are analyzed and compared with corresponding experimental data. Slightly better agreement with the experimental data is obtained with the deterministic stress model. It has been proven that the developed method of simulating the body force and blade blockage effect is effective in the simulation and simple in programming. In addition for low speed axial flow compressors with large axial spacing, the improvement of the flow prediction with the deterministic stress model was found to be not significant.