Experimental Study on Flame Behavior and NOx Emission in Counter-Swirl Injector for Gas-turbine Engine

A study was conducted on flame behavior and NO x emission characteristics in co-axial counter-swirl injector for gas turbine engine under various inner swirl levels and quarl angles.The study was carried out with a fixed total heat release rate of 5 kW, using global equivalence ratio, hydrogen co-firing ratio, quarl angle, and inner swirl number as key parameters.Five distinct flame shapes were identified based on the global equivalence ratio and hydrogen co-firing ratio.It was observed that the inner swirl number and quarl angle influence the mixing performance between the premixed methane-oxidizer flow through the outer nozzle and the hydrogen flow from the inner nozzle, as well as the recirculation zone, leading to variations in flame behavior and NO x emissions. Quarl NO x . 5 kW , , Quarl . 5 , Quarl ( ) NO x .