QUANTIFICATION AND MITIGATION OF THERMOCHEMICAL NON-EQUILIBRIUM IN HIGH-ENTHALPY HYPERSONIC WIND TUNNELS
Abstract
The proposed research aims to advance understanding of non-equilibrium phenomena in high-enthalpy, hypersonic wind tunnels and to develop novel strategies for experimental characterization and mitigation of non-equilibrium effects. Experiments will be conducted in the arc-heated facility at the University of Tennessee (UT). A major challenge associated with the design of hypersonic vehicles is the inability to accurately reproduce representative flows in ground testing facilities. It is well known that the freestream of conventional high-enthalpy hypersonic wind tunnels is affected by thermochemical non-equilibrium with vibrational excitation and dissociation of air molecules. As a result, even with the correct stagnation conditions, the freestream is not fully representative of real flight conditions leading to large uncertainties in the measurements. Quantification and control of non-equilibrium remains one of the major challenges for hypersonics research as the phenomenon is poorly understood with few existing diagnostic tools and no effective mitigation strategies. This research will provide better understanding of non-equilibrium flows and the fundamental knowledge needed for the development of next-generation hypersonic wind tunnels, which will better approximate the flow conditions encountered in flight. Specifically, the following research tasks will be performed: (1) Development of in situ non-intrusive optical diagnostics, based on Radar REMPI, able to quantitatively characterize vibrational excitation and dissociation rates of molecular air species. This task will provide the necessary tools to effectively investigate non-equilibrium. (2) Application of these techniques to quantitatively assess the effectiveness of novel strategies for non-equilibrium mitigation in high-enthalpy tunnels such as high-speed heating to avoid vibrational excitation and dissociation. Successful completion of the proposed work will significantly enhance the current understanding and research capabilities in hypersonics with game-changing impact on the development of the Air Force hypersonic program.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jan 21, 2022
- Source ID
- FA95502110183XX0
Entities
People
- Damiano Baccarella
Organizations
- Air Force Office of Scientific Research
- United States Air Force
- University of Tennessee