Numerical study on the effect of meridional width vaned diffuser on the performance of a modified centrifugal flow compressor

Abstract EN

In This paper, a numerical simulation that was made in the three-dimensional flow, carried out in a modified centrifugal compressor, having vaned diffuser stage, used as an auto-motive turbo charger.

In order to study the influence of vaned diffuser meridional outlet section with a different width ratio on the modified centrifugal compressor.

Moreover, the performance of the centrifugal compressor was dependent on the proper matching between the compressor impeller along with vaned diffuser.

In addition, the curves of polytropic efficiency, total pressure ratio, static pressure and aerodynamic characteristics were compared under different width ratio.

In addition, the velocity vectors in diffuser flow passages, the absolute Mach number and the secondary flow in cross-section near the outlet of diffuser were analyzed in detail under width ratio of 0.5, 0.7, 0.8, 1 and 1.2.

Another aim of this research was to study and simulate the effect of vaned diffuser on the performance of a centrifugal compressor.

The simulation was undertaken by using CFD analysis on aerodynamic flow to predict numerically the performance in terms of pressure ratio, poly tropic efficiency and mass flow rate for the centrifugal compressor stage.

The results were generated from CFD (ANSYS CFX) and were analyzed for better understanding of the fluid flow through centrifugal compressor stage and as a result when the width ratio is 0.5, the flow in diffuser passages tends to be uniformity.

The backflow and vortex near the pressure surface disappear, and the vortex and detachment near the suction surface decrease.

Conclusively, it was observed that the efficiency was increased and both the total pressure ratio and static pressure for 0.5 width ratio are increased.