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

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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.