用深度学习+伴随方法,实时调控湍流机翼气流,提升升阻比。
Active Control of Turbulent Airfoil Flows Using Adjoint-based Deep Learning
- 神经网络根据局部压力自适应调节喷射气压,实现动态控制。
- 在攻角5°~10°时升阻比显著提升,分离流明显减少。
- 2D训练模型可通用到3D场景,展现强鲁棒性,适合工程应用。
本文采用基于伴随的深度学习方法,训练神经网络流控器以优化雷诺数5×10⁴、马赫数0.4条件下二维和三维半无限NACA 0012机翼在攻角5°、10°、15°时的升阻比。通过直接数值模拟与大涡模拟,对可压缩非受限流场进行建模。控制动作通过上表面固定位置的吹吸喷口实现,由神经网络将局部压力测量映射为最优喷射总压,形成响应瞬变流场的传感反馈控制策略。利用自动微分构建伴随欧拉-纳维尔斯托克斯方程,计算流场对神经网络参数的敏感度。训练后的控制器显著改善升阻比并抑制流动分离,尤其在5°和10°攻角下效果突出。二维训练模型在三维流场中仍有效,表明伴随训练方法具有强鲁棒性;三维模型更精准捕捉流态,提升能效,使自适应(神经网络)与离线(恒定压力)控制性能相当。结果验证了该学习驱动方法在提升气动性能上的有效性。
原文摘要 · Abstract (English)
We train active neural-network flow controllers using a deep learning PDE augmentation method to optimize lift-to-drag ratios in turbulent airfoil flows at Reynolds number $5\times10^4$ and Mach number 0.4. Direct numerical simulation and large eddy simulation are employed to model compressible, unconfined flow over two- and three-dimensional semi-infinite NACA 0012 airfoils at angles of attack $α= 5^\circ$, $10^\circ$, and $15^\circ$. Control actions, implemented through a blowing/suction jet at a fixed location and geometry on the upper surface, are adaptively determined by a neural network that maps local pressure measurements to optimal jet total pressure, enabling a sensor-informed control policy that responds spatially and temporally to unsteady flow conditions. The sensitivities of the flow to the neural network parameters are computed using the adjoint Navier-Stokes equations, which we construct using automatic differentiation applied to the flow solver. The trained flow controllers significantly improve the lift-to-drag ratios and reduce flow separation for both two- and three-dimensional airfoil flows, especially at $α= 5^\circ$ and $10^\circ$. The 2D-trained models remain effective when applied out-of-sample to 3D flows, which demonstrates the robustness of the adjoint-trained control approach. The 3D-trained models capture the flow dynamics even more effectively, which leads to better energy efficiency and comparable performance for both adaptive (neural network) and offline (simplified, constant-pressure) controllers. These results underscore the effectiveness of this learning-based approach in improving aerodynamic performance.
Thank you to arXiv for use of its open access interoperability. PaperDance 不是 arXiv 官方产品;中文卡片由大模型生成,请以原文为准。