Optimization methods in conjunction with computational fluid dynamics are a key tool in advancing current rotor design. High-fidelity optimization of unsteady rotor flows in forward flight, however, is a challenging problem due to the high computational resources required. To minimize the computational costs, a fully turbulent, overset, adjoint harmonic-balance optimization framework has been developed, which maintains the fidelity of the Navier–Stokes equations. The framework is demonstrated in the aerodynamic redesign of the AH-64A rotor blade. An analysis of the optimized rotor blade is presented, including the key design features that contribute to the performance benefits in each of the examined design conditions. In particular, the benefits and drawbacks of rotor designs with an offloaded blade tip have been discussed. The formulation of the optimization objective function, blade surface parameterization, and treatment of trim were seen to have an impact on the final planform shape; and they have been deemed to be key in obtaining a practical rotor design suitable for use on real-life helicopters.

结合计算流体动力学的优化方法是推进当前转子设计的关键工具。然而，由于需要大量计算资源，前飞中非定常转子流的高保真优化是一个具有挑战性的问题。为了最小化计算成本，已经开发了一个完全湍流、重叠、伴随的谐波平衡优化框架，它保持了 Navier-Stokes 方程的保真度。该框架在 AH-64A 转子叶片的空气动力学重新设计中得到了展示。对优化的转子叶片进行了分析，包括有助于在每个检查的设计条件下提高性能的关键设计特征。特别地，已经讨论了具有卸载叶尖的转子设计的优点和缺点。优化目标函数的制定、叶片表面参数化和修剪处理被认为对最终平面形状有影响；它们被认为是获得适用于现实直升机的实用旋翼设计的关键。