Parametric study of detonation initiation using a hot jet in supersonic combustible mixtures

The effects of various flow or geometry parameters on detonation initiation in supersonic combustible mixtures using a hot jet were investigated, including the free stream Mach number Ma ∞ , the hot jet Mach number Ma j , the free stream pressure P ∞ , the hot jet pressure P j , the diameter of the hot jet D j , and the height of the free stream channel Hc. The results show that there exists a free stream Mach number range ( Ma ∞ min , Ma ∞ max ) for the successful initiation. When Ma ∞ is beyond that range, the hot jet is not able to initiate the detonation and the flow field maintains a stable shock wave or shock reflection induced by the hot jet. For the other parameters, including the hot jet Mach number, the free stream pressure, the hot jet pressure, the diameter of the hot jet, and the height of the free stream channel Hc, there exists a critical value for the detonation initiation. For the hot jet Mach number Ma j , the hot jet pressure P j , the diameter of the hot jet D j , when they are larger than the critical values, the initiation can be realized eventually and the larger the parameters the faster the initiation. Otherwise, the flow field will maintain the final stable state as the shock wave or shock reflection. For the free stream pressure P ∞ and the height of the free stream channel Hc, when they are larger than the critical values, the flow field will also maintain the final stable state. Otherwise, the detonation initiation can be realized eventually and the smaller the parameters the faster the initiation.