Optimization of Blade Sweep in a Transonic Axial Compressor Rotor

Abstract

This paper describes the optimization of blade sweep in a transonic axial compressor rotor. The shape optimization has been performed using response surface method and the three-dimensional Navier-Stokes analysis. Two shape variables of the rotor blade, which are used to define the rotor sweep, are introduced to increase the adiabatic efficiency of the axial compressor. Blade sweep has been used in the transonic compressor design with the intent of reducing shock losses. Throughout the optimization, optimal shape having a backward sweep is obtained. Adiabatic efficiency, which is the objective function of the present optimization, is successfully increased by 1.25 percent. Separation line due to the interference between a shock and surface boundary layer on the blade suction surface is moved downstream for the optimized blade compared to the reference one. It is noted that the increase in adiabatic efficiency for the optimized blade is caused by moving the separation line to the downstream on the blade suction surface.