Transition between detonation and deflagration in a tube with a cavity
In this paper, the transition of a detonation from deflagration was investigated numerically while a detonation wave propagates in a tube with a sudden change in cross section, referred to as the expansion cavity. The dispersion-controlled scheme was adopted to solve Euler equations of axis-symmetric flows implemented with detailed chemical reaction kinetics of hydrogen-oxygen (or hydrogen-air) mixture. The fractional step method was applied to treat the stiff problems of chemical reaction flow. It is observed that phenomena of detonation quenching and reigniting appear when the planar detonation front diffracts at the vertex of the expansion cavity entrance. Numerical results show that detonation front in mixture of higher sensitivity keeps its substantial coupled structure when it propagates into the expansion cavity. However, the leading shock wave decouples with the combustion zone if mixture of lower sensitivity was set as the initial gas.
KeywordsDetonation Wave Combustion Zone Detonation Front Mach Stem Mach Reflection
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- 3.E.G. Pantow, M. Fischer, and Th. Kratel: Decoupleing and recoupling of detonation waves associated with sudden expansion. Shock Waves 6, 131 (1996)Google Scholar
- 6.B.J. Mcbride, M.J. Zehe, and Sanford Gordon: NASA Glenn coefficients for calculating thermodynamic properties of individual species. NASA/TP-2002-211556 (2002)Google Scholar
- 7.Z. Jiang, K. Takayama, Y.S. Chen: Dispersion conditions for non-oscillatory shock capturing schemes and its applications. Comp Fluid Dynamics Journal 2(4), 137 (1995)Google Scholar
- 8.E. Schultz, J. Shepherd: Validation of detailed reaction mechanisms for detonation simulation. Graduate Aeronautical Laboratories, California Institute of Technology, Pasadena (2000)Google Scholar