Shape Optimization of Centrifugal Compressor Scroll for Turbocharger Using Adjoint Method

Abstract

The shape of the centrifugal compressor scroll for turbocharger was optimized by adjoint method. In this method, the sensitivity of the performance improvement to shape changes is calculated, and the shape is morphed based on the obtained sensitivity. As the result of optimization, the recirculation flow rate was reduced by the triangulated cross-sectional shape at winding start, and the separation of the recirculation flow was suppressed by the convex cross-sectional shape at winding end. In addition, in the performance test of the optimized scroll, a large efficiency improvement (approx.+1.5%) was achieved without any demerit against base scroll, and therefore the effectiveness of the shape optimization of centrifugal compressor scroll using adjoint method was confirmed.