Surrogate-based optimization of 3D afterbody nozzle

3D after-body nozzle is a main component to generate thrust and lift for air-breathing hypersonic vehicle. Optimization methods are needed in design process to maximum its aerodynamic performance, such as its lift and trust. However, to calculate the thrust and lift directly in the optimization process using 3D NS solver will costs too much time. In this article, a Kriging surrogate model is proposed adopting the method of design of experiment to replace direct CFD simulation in the optimization process of the 3D afterbody nozzle. Combining parameterized shape generating automatically using CATIA secondary development, 3D nozzle computation grid auto-generation, matured 3D N-S equation CFD solver, Kringing surrogate model and NSGA II multi-objects optimization, a 3D nozzle configuration is optimized in multi-objective way with these techniques. The nozzle thrust and lift have been improved evidently, and this optimization method can be widely used in engineering owning to its great efficiency.