Adjoint-based robust optimization design of laminar flow wing under flight condition uncertainties  

作　　者：Yifu CHEN Hanyue RAO Yiju DENG Tihao YANG Yayun SHI Junqiang BAI 

机构地区：[1]School of Aeronautics,Northwestern Polytechnical University,Xi’an 710072,China [2]The First Aircraft Design and Research Institute,Xi’an 710089,China [3]State Key Laboratory for Strength and Vibration of Mechanical Structures,School of Aerospace Engineering,Xi’an Jiaotong University,Xi’an 710049,China

出　　处：《Chinese Journal of Aeronautics》2023年第6期19-34,共16页中国航空学报（英文版）

摘　　要：It is an inherent uncertainty problem that the application of laminar flow technology to the wing of large passenger aircraft is affected by flight conditions.In order to seek a more robust natural laminar flow control effect,it is necessary to develop an effective optimization design method.Meanwhile,attention must be given to the impact of crossflow(CF)instability brought on by the sweep angle.This paper constructs a robust optimization design framework based on discrete adjoint methods and non-intrusive polynomial chaos.Transition prediction is implemented by coupled Reynolds-Averaged Navier-Stokes(RANS)and simplified e^(N)method,which can consider both Tollmien-Schlichting(TS)wave and crossflow vortex instability.We have performed gradient enhancement processing on the general Polynomial Chaos Expansion(PCE),which is advantageous to reduce the computational cost of single uncertainty propagation.This processing takes advantage of the gradient information obtained by solving the coupled adjoint equations considering transition.The statistical moment gradient solution used for the robust optimization design also uses the derivatives of coupled adjoint equations.The framework is applied to the robust design of a 25°swept wing with infinite span in transonic flow.The uncertainty quantification and sensitivity analysis on the baseline wing shows that the uncertainty quantification method in this paper has high accuracy,and qualitatively reveals the factors that dominate in different flow field regions.By the robust optimization design,the mean and standard deviation of the drag coefficient can be reduced by 29%and 45%,respectively,and compared with the deterministic optimization design results,there is less possibility of forming shock waves under flight condition uncertainties.Robust optimization results illustrate the trade-off between the transition delay and the wave drag reduction.

关 键 词：Adjoint method Gradient-based optimization Laminar-turbulent transition Robust design Uncertainty propagation 

分 类 号：V211.41[航空宇航科学与技术—航空宇航推进理论与工程]