Optimization strategy of supercritical laminar flow airfoil design

Journal:Beijing Hangkong Hangtian Daxue Xuebao

Abstract:A two-step optimization strategy for the supercritical laminar flow airfoil design is proposed in the paper. The γ-Reθttransition model coupled with the shear stress transportation (SST) turbulence model is used for prediction of airfoil boundary layer transition. The Class/Shape Transformation (CST) method is used to parameterize airfoil geometry. The parameters in the airfoil geometry model are used as the design variables. The first step of optimization is to increase the ratio of the laminar flow region. A genetic algorithm based on the Kriging surrogate model is employed to obtain the laminar flow airfoil with all constraints satisfied. The second step of optimization is to improve the optimization result of the first step, and to further increase the lift-to-drag ratio of the airfoil. A gradient based optimization is used to search optimal solution. The aerodynamic analysis during the second step optimization is implemented through the CFD code rather than the surrogate model. The example demonstrates that the supercritical airfoil NASA SC(2) 0412 can be optimized into a supercritical laminar flow airfoil by the two-step optimization method, the laminar region ratios on the airfoil upper and lower surface increase by 55.5% and 47.0% respectively, and the lift-to-drag ratio increases by 38.1%. © 2017, Editorial Board of JBUAA. All right reserved.

ISSN No.:1001-5965

Translation or Not:no

Date of Publication:2017-08-01

Co-author:邢宇,yxq

Correspondence Author:邢宇,ldm

Date of Publication:2017-08-01