Improvement of lean blow out performance of spray and premixed swirled flames using nanosecond repetitively pulsed discharges

Plasma-Assisted Combustion (PAC) has shown potential in improving the ignition, extinction, and dynamic performance of combustion systems. In this work, nanosecond repetitively pulsed (NRP) spark discharges are applied to extend lean blow out (LBO) limit SICCA-Spray burner. This laboratory-scale atmospheric test rig is equipped with a swirl spray injector representing an idealized fashion single sector gas turbine. Three fuels injection conditions considered: perfectly premixed methane–air, liquid heptane, dodecane injected as hollow cone sprays. The optimal electrode position that extends LBO found be near external edge outer recirculation zone (ORZ). Spectroscopic measurements show NRP sparks produce atomic species heat above adiabatic flame temperature. High-speed chemiluminescence images sequences indicate evolves similarly for all three from “M” or “V” shapes prevailing at ?=0.9 configuration where chemical conversion also takes place ORZ ?=0.63. A low frequency oscillation arises (?=0.57). Spray flames point, while plasma-assisted ones continue burn. It PAC provides significant improvement extinction performance, particular when operating fuel injection.