Numerical Investigation of Separation-Induced Transition and LSB Dynamics in Low-Reynolds Number Flows

低雷诺数流动中分离诱导转捩和LSB动力学的数值研究 自无人机和微型飞行器出现以来，低雷诺数流场已成为空气动力学研究的热点。驱动这种兴趣的是特定的层流到湍流的过渡过程，通常称为层流分离泡（LSB）。LSB的形成和动力学是造成这种流态下大多数气动性能退化的原因，包括最大和平均升力损失、失速角减小、俯仰力矩减小等。LSB还被证明强烈依赖于翼型几何形状和冲角条件（攻角、雷诺数、自由流湍流强度等）。为了（1）更好地理解物理基础，（2）提高在这种状态下飞行的可预测性，（3）导出性能相关性，（4）优化未来的设计，需要对这种复杂的转捩现象进行彻底的研究。本项目建议使用URANS方法进行广泛的调查，以获得成本效益，并使用高保真度的CFD工具（LES和混合URANS/LES）进行更物理合理的描述。我在不同的学术和工程问题的数值研究的专业知识，使用各种工具，使我能够肯定，一个显着的贡献将导致从这个项目。

Numerical Investigation of Separation-Induced Transition and LSB Dynamics in Low-Reynolds Number Flows The low Reynolds number flow regime has become a popular field of study in aerodynamics since the advent of unmanned aerial vehicles (UAV) and microaerial vehicles (MAV). Driving this interest is the particular laminar to turbulent flow transition process, commonly referred to as the laminar separation bubble (LSB). LSB formation and dynamics are responsible for most aerodynamic performance degradations in this flow regime, including loss of maximum and average lift, decreased stall angle, decreased pitching moments, etc. The LSB has also been shown to be strongly dependent on airfoil geometry and incidence conditions (angle of attack, Reynolds number, free stream turbulence intensity, etc.). The thorough investigation of this complex transition phenomenon is required in order to (1) better understand the physical fundations, (2) improve the predictability of flight in this regime, (3) derive performance correlations, and (4) optimize future designs. This project proposes an extensive investigation using the URANS approach for its cost-effectiveness, as well as higher fidelity CFD tools (LES and hybrid URANS/LES) for a more physically sound description. My expertise in the numerical investigation of different academic and engineering problems, using a variety of tools allows me to affirm that a significant contribution will result from this project.