基于N-S方程和离散共轭方法的气动外形设计

Aerodynamic design method based on N-S equations and discrete adjoint approach

快速准确的目标函数梯度计算方法是基于梯度信息的优化设计的关键技术之一。采用离散共轭方法计算目标函数关于设计变量的梯度,流动控制方程为三维N-S方程。对于离散共轭方程和流动控制方程均采用LU-SGS方法时间推进求解。检验了离散共轭方法计算梯度的准确性,利用该方法进行了机翼的优化设计与反设计,都获得了较好的结果。算例证明了本文方法可靠性好,效果令人满意。

The quick and accurate gradient calculation technique is one of the most important techniques of aerodynamic design optimization that based on gradient.A discrete adjoint approach is developed in this paper to get the gradient,and the flow governing equations are three dimensional N-S equations.Both the adjoint equations and the flow governing equations are solved by LU-SGS method.The gradient achieved by the present method is compared with those by finite difference method.A wing is firstly optimized and then revise designed by this method,and the results are satisfying.The test results show that the present method is reliable and efficient.