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Effects of hydrogen–air non–equilibrium chemistry on the performance of a model scramjet thrust nozzle

Published online by Cambridge University Press:  03 February 2016

R. J. Stalker
Affiliation:
Division of Mechanical Engineering, University of Queensland, Brisbane, Australia
N. K. Truong
Affiliation:
Division of Mechanical Engineering, University of Queensland, Brisbane, Australia
R. G. Morgan
Affiliation:
Division of Mechanical Engineering, University of Queensland, Brisbane, Australia
A. Paull
Affiliation:
Division of Mechanical Engineering, University of Queensland, Brisbane, Australia

Abstract

Two aspects of hydrogen-air non-equilibrium chemistry related to scramjets are nozzle freezing and a process called ‘kinetic afterburning’ which involves continuation of combustion after expansion in the nozzle. These effects were investigated numerically and experimentally with a model scramjet combustion chamber and thrust nozzle combination. The overall model length was 0·5m, while precombustion Mach numbers of 3·1±0·3 and precombustion temperatures ranging from 740K to 1,400K were involved. Nozzle freezing was investigated at precombustion pressures of 190kPa and higher, and it was found that the nozzle thrusts were within 6% of values obtained from finite rate numerical calculations, which were within 7% of equilibrium calculations. When precombustion pressures of 70kPa or less were used, kinetic afterburning was found to be partly responsible for thrust production, in both the numerical calculations and the experiments. Kinetic afterburning offers a means of extending the operating Mach number range of a fixed geometry scramjet.

Type
Research Article
Copyright
Copyright © Royal Aeronautical Society 2004 

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References

1. Ferri, A. Review of problems in application of supersonic combustion, Aeronaut J, September 1964, 68, (645), pp 575597.Google Scholar
2. Swithenbank, J. Hypersonic Air-Breathing Propulsion, 1967, Pergamon Press, Oxford, Progress in the Aerospace Sciences, Küchemann, D. (Ed), 8, pp 229294.Google Scholar
3. Franciscus, L.C. and Lexberg, E.A. Effects of exhaust nozzle recombination on hypersonic ramjet performance: II Analytical investigation, AIAA J, September 1963, 1, (9), pp 20772083.Google Scholar
4. Rizkalla, O., Chinitz, W. and Erdos, J. Calculated chemical and vibrational nonequilibrium effects in hypersonic nozzles, J Propulsion and Power, January-February 1990, 6, (1), pp 5057.Google Scholar
5. Harradine, D.M., Lyman, J.L., Oldenborg, R.C., Schott, G.L. and Watanabe, H.H. Hydrogen/air combustion calculations: the chemical basis of efficiency in hypersonic flows, AIAA J, October 1990, 28, (10), pp 17401744.Google Scholar
6. Sangiovanni, J.J., Barber, T.J. and Syed, S.A. Role of hydrogen/air chemistry in nozzle performance for a hypersonic propulsion system, J Propulsion and Power, January-February 1993, 9, (1), pp 134138.Google Scholar
7. Riggins, D.W. Thrust losses in hypersonic engines. Part 2: applications, J Propulsion and Power, March-April 1997, 13, (2), pp 288295.Google Scholar
8. Nishioka, M. and Law, C.K. A numerical study of ignition in the supersonic hydrogen/air laminar mixing layer, Combustion and Flame, 1997, 108, pp 199219.Google Scholar
9. Stalker, R.J. and Paull, A. Experiments on cruise propulsion with a hydrogen scramjet, Aeronaut J, January 1998, 102, (1011), pp 3743.Google Scholar
10. Stalker, R.J. Development of a hypervelocity wind tunnel, Aeronaut J, June 1972, 76, pp 374384.Google Scholar
11. Stalker, R.J. and Crane, K.C. A. Driver gas contamination in a high-enthalpy reflected shock tunnel, AIAA J, March 1978, 16, (3), pp 277279.Google Scholar
12. Brescianini, C.P. An Investigation of the Wall-injected Scramjet, PhD thesis, University of Queensland, Brisbane, 1993.Google Scholar
13. Patankar, S.V. and Spalding, D.B. Heat and Mass Transfer in Boundary Layers, Second Ed, 1970, International Textbook Co, London.Google Scholar
14. Elghobashi, S. and Spalding, D.B. Equilibrium chemical reaction of supersonic hydrogen-air jets (the ALMA computer program), 1977, NASA CR-2725.Google Scholar
15. Oldenberg, R., Chinitz, W., Friedman, M., Jaffe, R., Jachimowski, C., Rabinowitz, M. and Schott, G. Hypersonic combustion kinetics, 1990, National Aerospace Plane, NASP TM-1107, Wright-Patterson AFB, OH.Google Scholar
16. Mcintyre, T.J., Houwing, A.F.P., Palma, P.G., Rabbath, P.A.B. and Fox, J.S. Optical and Pressure measurements in shock tunnel testing of a model scramjet combustor, J Propulsion and Power, May-June 1997, 13, (3), pp 388394.Google Scholar
17. Paull, A., Stalker, R.J. and Mee, D.J. Scramjet thrust measurement in a shock tunnel, Aeronaut J, May 1995, 99, (984), pp 161163.Google Scholar
18. Stalker, R.J., Morgan, R.G. and Netterfield, M.P. Wave processes in scramjet thrust generation, Combustion and Flame, 1988, 71, pp 6377.Google Scholar