The current enhancement technique to achieve the deflagration-to-detonation transition (DDT) is through the use of solid obstacles in the detonation engines. However, the solid obstacles have numerous drawbacks including pressure losses and heat soaking, leading to the performance degradation of the detonation engine. Therefore, an alternate method has been approached using a reactive fluidic jet which has the potential to induce the turbulence and flame-vortex interactions, leading to the combustion acceleration. Flame acceleration and DDT process are characterized and analyzed by high speed imaging techniques, as well as pressure and flame wave profiles. The delay time and the locations of the reactive fluidic jets are intensively studied in this paper. With the help of the fluidic obstacle, the DDT time can be shortened successfully by 10%-30%. There is an optimal time to jet mixture into the detonation channel. The influence of the distance of jet to the endwall of igniter on the flame-flow interactions is revealed, the fluidic jet could be located in the initial deflagrated flame developing stage, leading to distinctly increase in turbulent flame accelerations. The present study provides details of the flame acceleration processes for the fluidic jets and the different regimes of detonation initiations.
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