基于低耗散格式的飞行器气动伴随优化设计方法

Aerodynamic adjoint-based optimization design method for aircraft based on low-dissipation scheme

  • 摘要: 在飞行器气动离散伴随优化设计系统中,流场输运方程与伴随方程的精度和鲁棒性主要受无黏项数值离散格式的影响。由于伴随方程求解的是流场的微分信息,伴随变量比流场输运变量更为敏感。针对飞行器气动伴随方程中无黏项的处理问题,本文推导了基于AUSMPW+格式的离散伴随方程与敏感度方程,进而提出了一种基于AUSMPW+低耗散格式的离散伴随优化方法。通过M6机翼与CRM翼身组合体算例对该方法进行验证,结果显示总阻力分别降低了28.1 counts和32.3 counts。计算与设计结果表明,所建立的低耗散格式伴随方程求解鲁棒性强,梯度计算精度高。该方法适用于飞行器三维复杂高精度流场求解及气动优化设计,可为工程实践中大规模设计变量优化问题提供可靠的数值工具。

     

    Abstract: In aerodynamic discrete adjoint optimization design systems for aircraft, the accuracy and robustness of the flow field transport equations and adjoint equations are primarily influenced by the numerical discretization schemes used for the inviscid terms. Since the adjoint equations solve the differential information of the flow field, the adjoint variables are more sensitive than the flow field transport variables, making the proper treatment of inviscid terms critically important. To address this issue, the discrete adjoint equations and sensitivity equations based on the AUSMPW+ scheme were systematically derived, and a novel discrete adjoint optimization method employing the low-dissipation AUSMPW+ scheme was proposed. The effectiveness of the proposed method was thoroughly validated through representative numerical examples, including the transonic M6 wing and the NASA common research model (CRM) wing-body configuration. The optimization results achieved remarkable total drag reductions of 28.1 counts and 32.3 counts, respectively. Extensive computational and design results consistently demonstrate that the adjoint equation solver using the low-dissipation scheme exhibits excellent robustness and high accuracy in gradient calculations. This method is applicable to three-dimensional, complex, high-precision flow field solutions and aerodynamic optimization design for modern aircraft configurations, providing a reliable and efficient numerical tool for large-scale design variable optimization problems in practical engineering applications.

     

/

返回文章
返回