基于迎风格式伴随方程的飞行器边界特性设计方法

A challenging and crucial aspect of aircraft design is defining the boundary characteristics of the aircraft, which dictate their safety and flying performance. In order to increase the precision, effectiveness, and resilience of complex flow problems, we suggested in this study that adjoint optimization methods be extended to the design of aircraft boundary features. We did this by developing an upwind scheme adjoint equation and various flux limiter treatments. Firstly, the basic principle of discrete adjoint gradient solution was introduced. This served as the foundation for deriving the adjoint equation's inviscid term and its variational form of boundary conditions. According to the processing method of the flux limiter, adjoint equations with first-order accuracy, second-order accuracy, and mixed accuracy were formed. Subsequently, the boundary treatments for the adjoint equation were studied. By using the ONERA M6 wing for gradient accuracy and robustness validation examples, the performance of solving adjoint equations using upwind and central schemes was compared, and the effects of limiter and boundary treatments on the convergence and gradient accuracy of the adjoint equations were analyzed. The effectiveness of the solver in designing aircraft cruise performance and boundary characteristics was verified through examples of CRM wing body at cruise and boundary characteristics optimization design. The computation and design outcomes demonstrated the robustness and high gradient accuracy of the upwind approach developed in the article, suggesting its potential for resolving design issues pertaining to aircraft boundary characteristics.