Influences of single-phase/two-phase transpiration cooling on detonation initiation and propagation

Pulse Detonation Engine (PDE) requires highly efficient cooling technology, especially under high frequency and high Mach number. Transpiration cooling is a promising cooling method considering its high cooling capacity. In this work, the influences of single/two phase transpiration cooling on the Deflagration to Detonation Transition process (DDT) and the propagation of detonation wave are investigated experimentally. Regarding single phase transpiration cooling, the supply pressure and cooling Cooling phase of the cooling gas affect the local equivalence ratio, which affects the flame structure and velocity. When Pc (Supply pressure) = 0.4-1.0 MPa, the effect of supply pressure on flame velocity is not significant (The DDT section, Cs(Cooling phase) <= -10 degrees; The detonation propagation section, Cs <= -5 degrees). The two-phase transpiration cooling coolant changes the blocking ratio and affects the flame acceleration. The two-phase transpiration cooling has less interference on detonation propagation section. Local divergent flow passage is formed where the transpiration layer ends. The detonation propagation velocity reduces, but the minimum of which is still higher than 90 % CJ velocity. No decoupling or failure of detonation wave occurs.