Experimental research on operating frequency effect on the characteristics of two-phase detonation initiation

In order to grasp the influence of detonation frequency on the initiation characteristics of two-phase multi-cycle detonation, an air-breathing pulse detonation engine mockup with high energy spark plug was designed and the experiments of detonation initiation process at different operating frequencies were carried out. The pressure distributions along the length of PDE mockup at different operating frequencies were contrasted and analyzed. Meanwhile, the relationship between the detonation frequency on the one hand and the initiation characteristic parameters on the other hand was discussed, such as the DDT transition distance, ignition delay time, DDT transition time and detonation initiation time and so on. The experimental results indicated that deflagration to detonation transition increased with increasing operating frequency. The operating frequency had obvious effect on ignition delay time and the detonation initiation time but had a weak effect on DDT time. As the operating frequency increased, the ignition delay time and detonation initiation time decreased linearly, while the DDT time declined slightly.