Temperature Measurement in a Shock Tunnel Using Tunable Diode Laser Absorption Spectroscopy
Quantitative measurement of the freestream temperature in the test section of a hypersonic shock tunnel, obtained using tunable diode laser absorption spectroscopy (TDLAS) technique, is presented in this work. Water vapor absorption lines near 1392 nm were probed using a vertical-cavity surface-emitting laser scanned at 25,000 Hz to get the time-resolved measurement of temperature in a Mach number M = 8 hypersonic flow. Three different enthalpy cases – 2.57, 2.23, and 2.01 MJ/kg – were studied in the shock tunnel. Freestream temperature was extracted from the absorbance spectra obtained using direct absorption scheme, by using two-line ratio method. The measured temperatures were compared with the theoretically predicted values.
The work presented in this paper has been funded by Defence Research and Development Organization (DRDO) and Science and Engineering Research Board (SERB), Department of Science and Technology (DST), India. The authors acknowledge their support.
- 1.J.J. Bertin, Hypersonic Aerothermodynamics (AIAA, Washington, DC, 1994)Google Scholar
- 2.J.D. Anderson, Hypersonics and High Temperature Gas Dynamics (McGraw Hill Publications, New York, 1989)Google Scholar
- 4.S. D. Wehe, D. S. Baer, R. K. Hanson, Tunable diode-laser absorption measurements of temperature, velocity, and H2O in hypervelocity flows. in Proceedings of the 33rd Joint Propulsion Conference and Exhibit, Joint Propulsion Conferences, AIAA 97–3267 (1997)Google Scholar
- 5.J. Kurtz, M. Aizengendler, Y. Krishna, P. Walsh, S. O’Byrne, Flight test of a rugged scramjet—inlet temperature, in 53rd AIAA Aerospace Sciences Meeting, 1–18 January (2015)Google Scholar
- 8.Y. Krishna, S.L. Sheehe, S. O’Byrne, A time-resolved temperature measurement system for free-piston shock tunnels, in 31st AIAA Aerodynamic Measurement Technology and Ground Testing Conference, Dallas, 22–26 (2015)Google Scholar