Numerical Simulation Of Shock-flame Interactions In Channels With Obstacles

The Pulse Detonation Engine(PDE) is a new concept engine, and the research on the deflagration to detonation(DDT) always be the key technology in the developing of the PDE. The DDT involves the shock-flame interactions and the shock-shock indentations.In this paper, the numerical simulation technique is used to investigating the shock-flame interactions in the channels with obstacles. The dispersion-controlled dissipative scheme (DCD)is adopted to solve Euler equation with detailed chemical reaction kinetics of the hydrogen-oxygen mixture. Meanwhile the splitting-up method is adopted to solve the rigidity problems caused by the coupling of flows and chemical reactions.The shock-flame interactions, DDT and the process of generating hot spots are studied in the channels with symmetrical and staggered obstacles, and then by changing the parameters of obstructions to study the differences in the above-mentioned phenomenon. The results show that when the shock crossed over the flame, the burning rate of the flame had been accelerated, and then the volume of the combustion products had been increased caused by the energy released in the flame propagation, and thus produce a series of combustion compression wave. The formation of hot spots could be achieved through the superposition of waves as well as the interaction between the decaying explosive detonation wave and flame fronts. The hot spot can't trigger the detonation unless there have sufficient energy to support.The presence of obstacles can create the space needed by the development of the hot spots, while the detonation was triggered through the accumulation of energy in the recirculation zone in front of the obstacles, but at the same time the existence of obstacles caused the flow resistance loss in the flow field which is not conductive to the realization of DDT.At last, the parameters of obstacles must be chosen by carefully considering.The research achievements can have a certain value to the research of DDT, and provide a little help for future studies.