The inclusion of transition to turbulence effects in aerodynamic shape optimization makes it possible to use it as a tool for the design of airframes with laminar flow. Modified Reynolds-Averaged Navier–Stokes (RANS) models that consider transition to turbulence have gained traction in the computational fluid dynamics (CFD) community. These models enable the computation of transitional flows without the need for external modules. In this work, we use a smooth version of the amplification factor transport (AFT) model, called AFT-S, to perform gradient-based aerodynamic shape optimization (ASO) of airfoils in subsonic and transonic flow conditions. We investigate the benefits of including transition effects into the optimization process and assess the impact of losing laminar flow when early transition to turbulence occurs due to surface contamination. Our results indicate that our design optimization approach yields lower drag airfoils when transition effects are considered. For the transonic case, the optimizer trades between shock wave strength and laminar flow extension to minimize drag.

在空气动力学形状优化中纳入了湍流过渡效果，因此可以将其用作设计具有层流的飞机机身的工具。考虑到湍流过渡的改进的雷诺平均纳维尔–斯托克斯（RANS）模型在计算流体力学（CFD）社区中获得了关注。这些模型无需外部模块就可以计算过渡流。在这项工作中，我们使用称为AFT-S的平滑形式的放大因子传输（AFT）模型，在亚音速和跨音速流动条件下对机翼进行基于梯度的空气动力学形状优化（ASO）。我们研究了将过渡效应包括到优化过程中的好处，并评估了由于表面污染而导致早期过渡到湍流时失去层流的影响。我们的结果表明，当考虑过渡效果时，我们的设计优化方法可产生较低的阻力翼型。对于跨音速情况，优化器在冲击波强度和层流扩展之间进行权衡以最大程度地减小阻力。