Aerodynamic Design and Numerical Analysis of Low Speed Tandem Bladed Axial Flow Compressor

Abstract

An axial compressor compresses the fluid to a required pressure while leaving it. Due to design restrictions in the rate of change of area across the diffusing passage, the stage pressure rise is limited compared to the stage pressure rise across turbine blades. Because of the presence of negative pressure gradient across the direction of flow a reverse flow could take place during the compression process. Therefore the diffusion process has to be slow, such that the compressor should compress the fluid without producing reverse flow. This paper deals with the numerical design and the flow prediction of a subsonic compressor stage with help of simulation software. The study includes results from different rotor stator interfaces and controlled diffusion study is done with the help of changing various blade parameters such as deviation angle of rotor, stator and thickness profile. The tandem blade concept is also introduced in the report. The results indicate that the required pressure rise was obtained with the help of changing the stator deviation angle and thickness of stator profile.