Hypervelocity Shock Tunnels

High-fidelity models of high-enthalpy non-equilibrium airflows are a vital tool for designing hypersonic vehicles such as superfast commercial aircraft, missiles, and spacecraft during reentry.

The Hanson Research Group is part of a multi-university collaboration with researchers at Caltech and the University of Minnesota working to improve and validate a promising new high-enthalpy flow model. Our group leverages our spectroscopy expertise to deploy a suite of sensitive and robust laser-based diagnostics to make precise, time-resolved measurements of high-energy flows around representative hypersonic models.

These diagnostics target a wide array of chemical species present in high-energy air, notably nitric oxide (NO), carbon dioxide (CO₂), and carbon monoxide (CO), as well as exotic trace species such as atomic potassium (K) and excited-state oxygen (O*) [1–3].

Our measurements characterize the freestream operating conditions of these facilities and provide the crucial information necessary to validate and improve the theoretical model developed by our collaborators. Hypersonic flow experiments are conducted at the T5 Reflected Shock Tunnel at Caltech, with additional experiments in the Caltech Hypervelocity Expansion Tube to ensure facility independence.

To learn more, check out some of our publications:

[1] P. M. Finch, J. J. Girard, C. L. Strand, W. M. Yu, J. M. Austin, H. G. Hornung, and R. K. Hanson, “Measurements of Time-Resolved Air Freestream Nitric Oxide Rotational, Vibrational Temperature and Concentration in the T5 Reflected Shock Tunnel,” AIAA Propulsion and Energy Forum 2020. DOI: 10.2514/6.2020-3714

[2] J. J. Girard, P. M. Finch, T. Schwartz, W. M. Yu, C. L. Strand, J. M. Austin, H. G. Hornung, and R. K. Hanson, “Characterization of the T5 Reflected Shock Tunnel Freestream Temperature, Velocity, and Composition using Laser Absorption Spectroscopy,” AIAA Propulsion and Energy Forum 2021. DOI: 10.2514/6.2021-3525

[3] T. Schwartz, J. J. Girard, P. M. Finch, W. M. Yu, J. M. Lawson, C. L. Strand, J. M. Austin, H. G. Hornung, and R. K. Hanson, “Characterization of the Caltech Hypervelocity Expansion Tube via Tunable Diode Laser Absorption Spectroscopy,” AIAA Propulsion and Energy Forum 2021. DOI: 10.2514/6.2021-3524