动力短舱多点气动优化设计OA

Design of the nacelle for a transonic engine is highly complicated and always a tradeoff between contradicting design objectives.In this paper,an optimization system for nacelle design is built up to improve the aerodynamic performance of a powered-on engine nacelle at two critical operation conditions.The class shape transformation(CST)method is developed for the parameterization of nacelle contour.The Pareto genetic algorithm(PGA)and the Kriging model are integrated by the loose surrogate management framework.At cruise,the minimization of external peak Mach number is the target function for total drag reduction and improving nacelle external performance.At maximum thrust condition,satisfied air supply should be ensured and the intake peak Mach number around throat is minimized to improve nacelle internal performance.Compared with the reference design,optimized nacelles obtain better performances with respect to both objectives,resulting in a peak Mach number reduction about 5%at cruise and 10%at full thrust condition.The parameter influence analysis indicates that the nacelle leading edge parameters have significant but different impact on nacelle internal and external performance.They should be chosen as the main design variables for integrated optimization design of the nacelle.The Pareto front can provide multiple choices for engineering applications.The results indicate that the optimization design system established in this paper provides an effective tool for the design of powered-on nacelles,and the optimization design results are of practical value.