Effect of different step heights on ignition and blowout performance of internally-staged combustor

A lean-burn internally-staged combustor was designed. Using a single module rectangular test article, the effects of three different step heights on ignition and blowout performance were studied herein. Only the pilot stage nozzle was fueled in the tests. The lean ignition test was operated with normal and negative inlet pressures under normal inlet temperatures condition, and the lean blowout test was operated with the normal and raised inlet temperature under the normal inlet pressure condition. The experimental results indicate that the lean ignition and blowout boundaries are simultaneously widened with the increasing the step height; the inlet temperature rise is good for lean blowout performance with narrowing the lean blowout fuel air ratio differences in these three cases, and the maximum differences decrease from 40% to 13% under the test condition of the inlet temperature of 320-570 K; the ignition performance under the negative inlet pressure and normal inlet temperature condition is rather good for all three cases with little difference of the lean ignition fuel air ratio, and the maximum differences don't exceed 10% under the test condition of the liner total pressure drop of 0.5%-1.5%.