Experimental investigation of C-shape embedded multi-channel plasma igniter in a single-head swirl combustor

Abstract A C-shape embedded multi-channel plasma igniter (CEMPI) is presented in this paper. Compared with traditional spark igniter (SI), it has a deeper penetration depth of fire kernel. The fuel supply pressure was kept at 0.2 MPa for the ignition tests. The ignition processes of two igniters at different air flow in a single-head swirl combustor were captured by using the technology of CH* chemiluminescence imaging. The influence of air flow on the ignition process and the ignition characteristics of two igniters were studied. The results show that the ignition dynamic process can be divided into four stages: fire kernel growth stage, flame stagnation stage, flame propagation stage and overall flame stage. To some extent, increasing air flow can shorten the ignition delay caused by flame stagnation, improve the flame propagation speed, and form overall flame earlier, which is conducive to fast ignition. Compared with SIs, CEMPIs can produce larger and more powerful fire kernel, which can penetrate deeper into the central recirculation zone and touch combustible mixture to generate initial flame. It also has a faster flame propagation speed to reduce the ignition time significantly. In addition, the CEMPI can widen the lean ignition boundary and has a more significant ignition advantage when the air flow is small.