The non-premixed ethylene ignition in supersonic flow-field was experimentally conducted to obtain the events of successful/failed flame propagation and the evolution of shock wave train during ignition transient using high speed photography and schlieren method. The key flow characteristics such as fuel distribution

length of recirculation zone

effect of shock wave train and air throttling affecting flame development and the modes of flame extinguishment were analyzed with the measurement of NPLS (nano-particle-based planar laser scattering) and PIV (particle image velocimetry) technology by combing with large eddy simulation data. The results showed that the shock train was pushed forward during the process of flame initiation leading to the fuel mass fraction difference between the conditions before and after ignition. The recirculation zone trapped in the fore corner of cavity was essential to the creation of initial flame

in which the ignition energy accumulated and the flame expanded and transported downstream until cavity trapped flame and positive feedback was built up. The fuel distribution within cavity was influenced by the position and pressure of fuel injection and can be accommodated by direct injection within cavity

which was beneficial for the initial flame kernel propagation while avoiding extinguishment caused by feedback.