Match-based pseudo-MAP full-operation-range optimization method for a turbocharger compressor

Abstract

To achieve full-operation-range performance optimization of a compressor and better matching performance with an engine in an accurate and efficient way, a novel pseudo-MAP optimization method is proposed. The pseudo-MAP is a contour-map (MAP) with the performance of only nine compressor characteristic operating points. As these nine points all represent the extreme and intermediate operation conditions in a compressor MAP, there are strong similarities between the compressor MAP and its pseudo-MAP. To verify that the compressor full-operation-range optimization can be replaced by the optimization of the pseudo-MAP, the performance of all the nine points are set as the optimization objectives. The approximation relation between the optimization objectives and the factorial analysis-screened compressor parameters is constructed via experimental design (DoE) and the radial basis function (RBF), and then, a multi-objective optimization for 18 optimization objectives is conducted by using a genetic algorithm (NSGA-II). After optimization, the choke flow of one compressor increases by 20%, and its maximum efficiency increases to 80%. Moreover, the pressure ratio significantly increases at medium or high flow, and the variation within the entire flow range is suppressed. As a result, the engine matched with the optimized compressor provides more power with higher efficiency and stability, which verifies the feasibility of the pseudo-MAP optimization method.