UT Austin is the lead institution for a AFOSR/NASA University Leadership Initiative program that focuses on developing a new measurement technology for hypersonic flight. This multi-university research and educational project is called FAST: Full-Airframe Sensing Technology for Hypersonic Aerodynamics Measurements. The FAST concept is that aerodynamic loads are “encoded” in the structural deformation of the vehicle, and so sufficiently accurate measurements of the deformation should enable the integrated and distributed aerodynamic pressure loads over the external surface of the vehicle. [Read more…]
Flow-structure interaction: Compliant panel under a compression ramp shock / boundary layer interaction
Flow-structure interaction (FSI) is important in high-speed flight because thin structures, such as the vehicle skin, are subjected to strong vibratory interaction with the flow. This interaction can lead to fatigue and failure of vehicle structures. We are investigating the flow-structure dynamic interaction of a compliant panel exposed to Mach 2 and Mach 5 shock-boundary layer interaction. The interaction is generated by a compression ramp that is located at the downstream edge of a flat compliant panel inserted flush with the floor of the wind tunnel. The flow-structure interaction is being studied by making simultaneous high-speed measurements of panel displacement, surface pressure and flow velocity using the digital image correlation (DIC), pressure sensitive paint (PSP) and particle image velocimetry (PIV) techniques, respectively. [Read more…]
Characterization of an inductively-coupled plasma torch for validation of exascale predictive simulations
This project is part of a much larger project that is supported by the DOE Predictive Science Academic Alliance Program (PSAAP). The UT PSAAP effort is led by the PECOS Center, which is part of the Oden Institute. The overall objective of the project is to develop advanced predictive simulations of inductively-coupled plasma torches that include multiple physical phenomena such as flow and turbulence, high-temperature air chemistry, electromagnetism, thermal non-equilibrium and radiation. A major thrust of the project is to undertake rigorous uncertainty quantification of the simulation, which requires access to validation data relevant to the various phenomena of interest. Our lab will contribute to the experimental validation effort by characterizing the range of operation of the torch, measuring the magnetic field strength inside the torch without plasma, characterizing the velocity field in the torch by using a non-reacting replica, and applying emission and laser spectroscopic methods to infer the state and degree of non-equilibrium under various conditions. [Read more…]
Ablation of high-temperature materials
A wide range of high-temperature materials are being studied using our 50 kW ICP Torch. The materials being tested have potential application in the thermal protection systems for hypersonic vehicles that are being developed by the U.S. Army. The materials being tested include various polymer matrix composites as well as newly-developed 3D-printed materials. Under this project, the ICP Torch is being modified in two ways to achieve a greater range of conditions. The first modification is to add a nozzle that accelerates and focuses the plasma to achieve higher heat fluxes, but over a smaller area. The second modification is to exhaust the torch through a nozzle into a vacuum tank to achieve a hypersonic hot-air plume. [Read more…]
Boundary Layer Flashback in Swirl Flames
Flame flashback is the uncontrolled upstream propagation of a premixed flame, and can lead to thermal damage of components in gas-turbine combustors. We are studying the type of flashback where the flame propagates within the wall boundary layer of a swirling flow. This work is relevant to gas-turbine combustors that operate with high-hydrogen-content syngas fuels derived from coal gasification. Sponsored by DOE UTSR. [Read more…]
Flashback in High-Pressure Swirl Flames
The effect of pressure is being studied on the flashback dynamics of turbulent swirl flames. This work is relevant to gas-turbine combustors that will operate with high-hydrogen-content syngas fuels derived from coal gasification. Sponsored by DOE UTSR. [Read more…]
Physics and Control of Unstart in Supersonic Inlet-Isolator Configurations
This study seeks to gain understanding of the physics of supersonic inlet unstart using high speed schlieren, PIV and fast response pressure measurements. ; A simplified inlet/isolator model with plexiglass sidewalls is used. ; With further understanding of unstart, passive and active control methods involving vortex generators and vortex generator jets can be investigated. [Read more…]
Investigation of unsteadiness of shock-induced separated flows
In this project we are investigating the low frequency unsteadiness that characterizes the interaction of a shock wave with a turbulent boundary layer. This work has implications for the fatigue of structures and effectiveness of control surfaces on high speed aircraft and missiles. Our approach is to combine fast response pressure measurements with advanced optical diagnostics, such as planar laser scattering (PLS) from a condensed fog, and particle image velocimetry (PIV). An example PLS image taken in the Mach 5 wind tunnel is shown. The flow moves toward the compression ramp at the far right. The image reveals large-scale turbulent structures and their interaction with the separation shock. Sponsored by the U.S. Army Research Office. [Read more…]