CAREER: Fluid-thermal-structural interactions of compressible turbulent flows over flexible panels

了解飞行器（如飞机）与周围空气的相互作用是很重要的。复杂的机械和热相互作用发生在大气飞行和推进在高速。例如，当强大的压缩改变了薄型柔性固体板上的流动时，由此产生的振动、非定常流动和强烈的加热会导致结构疲劳，从而降低气动控制和推进性能。提高对这些相互作用的理解对于设计更高效、安全和可靠的空间发射系统、行星探测器、大气超音速和高超音速航空运输装置、火箭和超音速内燃机非常重要。提出的工作旨在通过数值模拟和理论研究这些耦合相互作用。该项目还将包括为研究生和本科生学习用于科学发现的计算流可视化技术的教育活动，以及与当地一所小学的STEM教育工作者合作的外展计划，该计划将使用流可视化向3 -5年级的学生介绍流体运动的基本概念。本项目的目标是阐明与强压缩和膨胀波相互作用的分离湍流的流动物理是如何被薄柔性板的流体-热-结构耦合所改变的。本研究的特点是：1)压缩波对湍流长度和时间尺度的放大；2)湍流、压缩/膨胀系统和柔性板之间的能量传递机制；3)壁面变形与非定常流动动力学的同步、调节和自维持；4)壁面附近湍流的热失稳；5)交替触发流动不稳定性（如纵向涡和剪切涡脱落），导致时空不均匀性。三个数值研究将涉及统计上的二维结构，随后是三维效应，以及现实流动条件下的加热/冷却壁相互作用和有利于强动态耦合的面板材料特性。提出的高保真数值模拟方法结合了专门的流动、固体和热求解器，并将在复杂的几何形状中实现准确和计算上可行的预测。这种模拟流体流动和固体结构与热耦合相互作用的方法有望使其他工程学科受益，并为未来的研究铺平道路，这些研究包括化学反应、辐射、跃迁和表面粗糙度等额外的物理学。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Understanding the interactions of flying vehicles (e.g., airplanes) and the surrounding air is important. Complex mechanical and thermal interactions occur during atmospheric flight and propulsion at high speeds. For example, when a strong compression changes the flow over a thin flexible solid panel, the resulting vibrations, unsteady flow motions, and intense heating can lead to structural fatigue with reduced aerodynamic control and propulsive performance. Improved understanding of these interactions is important to the design of more efficient, safe, and reliable space launch systems, planetary probes, atmospheric supersonic and hypersonic air transportation devices, rockets, and supersonic combustion engines. The proposed work aims to study these coupled interactions through numerical simulations and theory. The project will also encompass educational activities for graduate and undergraduate students to learn computational flow visualization techniques for scientific discovery, and an outreach program, in partnership with STEM educators at a local elementary school, that will use flow visualizations to introduce basic notions of fluid motion to 3rd-5th grade students.The goal of this project is to elucidate how the flow physics of separated turbulent flows interacting with strong compression and expansion waves are altered by the fluid-thermal-structural coupling with thin, flexible panels. This research will characterize: 1) amplification of turbulence length and time scales by compression waves; 2) energy transfer mechanisms between the turbulent flow, the compression/expansion system, and the flexible panel; 3) synchronization, modulation and self-sustainment of wall deformation and unsteady flow dynamics; 4) thermal de/stabilization of the turbulent flow near the wall; 5) alternate triggering of flow instabilities (such as longitudinal vortices and shear vortex shedding) leading to spatiotemporal inhomogeneities. Three numerical studies will address statistically two-dimensional configurations, followed by three-dimensional effects, and heated/cooled-wall interactions under realistic flow conditions and panel material properties conducive to strong dynamic coupling. The proposed high-fidelity numerical simulation methodology incorporates specialized flow, solid, and thermal solvers, and will enable accurate and computationally feasible predictions in complex geometries. The developed approach to simulate interactions of fluid flows and solid structures with thermal coupling is expected to benefit other engineering disciplines and pave the way for future studies that incorporate additional physics such as chemical reactions, radiation, transition, and surface roughness.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.