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A numerical study on the mixing of air and hydrogen in a scramjet combustor

Published online by Cambridge University Press:  03 February 2016

M. Ali
Affiliation:
Department of Mechanical Engineering, University of Engineering and Technology (BUET), Dhaka, Bangladesh
T. Fujiwara
Affiliation:
Department of Aerospace Engineering, Nagoya University, Nagoya, Japan

Abstract

A numerical study on mixing of air and hydrogen is performed by solving two-dimensional full Navier-Stokes equations. The main stream is air of Mach 5 entering through the configured inlet of the combustor and gaseous hydrogen is injected from the configured jet on the side wall. Supersonic mixing and diffusion mechanisms of a transverse hydrogen jet in two-dimensional finite air streams have been analyzed and discussed. The computed results are compared with the experimental data and show good agreement. For an otherwise fixed combustor geometry, the air inlet width and injection angle are varied to study the physics of mixing and flow field characteristics. On the effect of inlet width variation, two competing phenomena have been observed: (i) upstream of injector the strength of recirculation is higher for wider inlet and consequently the mixing increases, and (ii) downstream, the diffusion of hydrogen decreases with the increase of inlet width and eventually mixing decreases. As a result, in far downstream the mixing efficiency increases up to certain inlet width and then decreases for further increment of inlet width. For the variation of injection angle results show that upstream of injector the mixing is dominated by recirculation and downstream the mixing is dominated by mass concentration of hydrogen. Upstream recirculation is dominant for injecting angle 60° and 90°. Incorporating the various effects, perpendicular injection shows the maximum mixing efficiency and its large upstream recirculation region has a good flame holding capability.

Type
Research Article
Copyright
Copyright © Royal Aeronautical Society 2005 

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References

1. Brown, G.L. and Roshko, A.. On density effects and large structure in turbulent mixing layer, 1974, J Fluid Mech, 64, (4), pp 575816.Google Scholar
2. Papamoschou, D. and Roshko, A.. Observation of supersonic free shear layers, 1986, AIAA Paper, 86-0162.Google Scholar
3. Rogers, R.C.. A study of the mixing of hydrogen injected normal to a supersonic airstream, 1971, NASA TN, D-6114.Google Scholar
4. Kraemer, G.O. and Tiwari, S.N.. Interaction of two-dimensional transverse jet with a supersonic mainstream, 1983, NASA CR, 175446.Google Scholar
5. Thayer, W.J. and Corlett, R.C.. Gas dynamic and transport phenomena in the two-dimensional jet interaction flow field, AIAA J, 1972, 10, pp 488493.Google Scholar
6. Weidner, E.H. and Drummond, J.P.. A parametric study of staged fuel injector configurations for scramjet applications, 1981, AIAA Paper 81-11468.Google Scholar
7. Yokota, K. and Kaji, S.. The three-dimensional supersonic flow and mixing fields with a perpendicular air injection from a finite length slit, Trans. Japan Soc Aero Space Sci, 1996, 39, (124), pp 173183.Google Scholar
8. Yokota, K. and Kaji, S.. The effects of aspect ratio of a finite length slit on the mixing in the three-dimensional supersonic flow, Trans. Japan Soc Aero Space Sci, 1996, 39, (124), pp 199210.Google Scholar
9. Drummond, J.P. and Weidner, E.H.. Numerical study of a scramjet engine flow field, January 1981, AIAA Paper, 81-0186.Google Scholar
10. Ali, M., Fujiwara, T. and Leblanc, J.E.. Influence of main flow configuration on mixing and flameholding in transverse injection into supersonic airstream, 2000, Int J Eng Sci, 38, pp 11611180.Google Scholar
11. Ali, M., Fujiwara, T. and Leblanc, J.E.. The effects of backward-facing step on mixing and flame holding in supersonic combustor, 2001, J Energy, Heat & Mass Trans, 23, pp 319338.Google Scholar
12. Ali, M. and Fujiwara, T.. Penetration and mixing of hydrogen injected normal to a 2-Dimensional parallel supersonic flow, 1997, Trans. Japan Soc Aero Space Sci, 40 (130), pp 248261.Google Scholar
13. Rausch, V.L., McClinton, C.R. and Hicks, J.W.. Scramjet breath ew life into hypersonics, July 1997, Aerospace America, pp 4046.Google Scholar
14. Moss, J.N.. Reacting viscous-shock-layer solutions with multicomponent diffusion and mass injection, NASA TR, 411, 1974.Google Scholar
15. White, F.M., Viscous Fluid Flow, 1974, McGraw-Hill, New York.Google Scholar
16. Reid, R.C. and Sherwood, T.K., The Properties of Gases and Liquids, 1966, Second Edition, McGraw-Hill, New York, pp 520543.Google Scholar
17. Baldwin, B.S. and Lomax, H.. Thin layer approximation and algebraic model for separated turbulent flows, 1978, AIAA Paper, 78257.Google Scholar
18. Yee, H.C.. A class of high-resolution explicit and implicit shock capturing methods, 1989, NASA TM, 101088.Google Scholar
19. Yee, H.C.. Upwind and symmetric shock-capturing schemes, December 1990, NASA TM, 89464.Google Scholar
20. Tabejamaat, S.J.U.Y. and Niioka, T.. Numerical simulation of secondary combustion of hydrogen injected from preburner into supersonic airflow, AIAA J, 1997, 35, (9), pp 14411447.Google Scholar