Low-Frequency Unsteadiness of Pressure-Induced Turbulent Separated Flows

湍流边界层的分离和再附着在空气动力学系统中很常见，通常对其性能不利。与分离和重新连接流动相关的压力和速度的不稳定会导致振动、噪音，甚至在高速流动的情况下会产生不稳定的热负荷。然而，目前的工程预测方法仍然不足以准确地模拟这些现象。因此，需要更好地理解分离和再附着的物理学，以便提高我们在技术应用中模拟和最终控制这些流动的不稳定方面的能力。 提出的研究计划的目的是加深我们对驱动压力诱导的湍流分离流低频非定常行为的物理机制的理解，并提出基于物理的控制这种不稳定行为的策略。我们计划结合实验、数值和理论方法来实现这一目标。

Separation and reattachment of turbulent boundary layers are common in aerodynamic systems and are often detrimental to their performance. The unsteadiness in pressure and velocity that is associated with separating and reattaching flows can lead to vibration, noise, and even unsteady thermal loads in the case of high-speed flows. Yet current engineering prediction methods are still often inadequate to accurately model these phenomena. A better understanding of the physics of separation and reattachment is therefore required in order to improve our capability of modeling and eventually controlling the unsteady aspects of these flows in technological applications. The goal of the proposed research program is to further our understanding of the physical mechanisms that drive the low-frequency, unsteady behavior of pressure-induced turbulent separated flows and to propose physics-based strategies to control this unsteadiness. We plan to combine experimental, numerical, and theoretical approaches to achieve this goal.