Effect of constant eddy viscosity assumption on optimization using a discrete adjoint method  

作　　者：Hangkong WU Dingxi WANG Xiuquan HUANG 

机构地区：[1]School of Power and Energy,Northwestern Polytechnical University,Xi’an 710072,China

出　　处：《Chinese Journal of Aeronautics》2023年第11期102-118,共17页中国航空学报（英文版）

基　　金：supported by the National Science and Technology Major Project,China(No.2017-II-0009-0023);China’s 111 project(No.B17037);sponsored by Innovation Foundation for Doctor Dissertation of Northwestern Polytechnical University,China.

摘　　要：This paper presents a thorough study of the effect of the Constant Eddy Viscosity(CEV)assumption on the optimization of a discrete adjoint-based design optimization system.First,the algorithms of the adjoint methods with and without the CEV assumption are presented,followed by a discussion of the two methods’solution stability.Second,the sensitivity accuracy,adjoint solution stability,and Root Mean Square(RMS)residual convergence rates at both design and offdesign operating points are compared between the CEV and full viscosity adjoint methods in detail.Finally,a multi-point steady aerodynamic and a multi-objective unsteady aerodynamic and aeroelastic coupled design optimizations are performed to study the impact of the CEV assumption on optimization.Two gradient-based optimizers,the Sequential Least-Square Quadratic Programming(SLSQP)method and Steepest Descent Method(SDM)are respectively used to draw a firm conclusion.The results from the transonic NASA Rotor 67 show that the CEV assumption can deteriorate RMS residual convergence rates and even lead to solution instability,especially at a near stall point.Compared with the steady cases,the effect of the CEV assumption on unsteady sensitivity accuracy is much stronger.Nevertheless,the CEV adjoint solver is still capable of achieving optimization goals to some extent,particularly if the flow under consideration is benign.

关 键 词：Aeroelastic Aerodynamic Constant eddy viscosity assumption Discrete adjoint method Sensitivity TURBOMACHINERY 

分 类 号：O17[理学—数学]