Electrically driven combustion near the plane wall in a supersonic duct

¹ Joint Institute for High Temperatures Russian Academy of Sciences Izhorskaya Str. 13 b2, Moscow 125412, Russia
² ONERA/DEFA/EFCA Fort de Palaiseau, Chemin de la Hunire 91761, France

Abstract

The ultimate objective of this work was to enhance the performance of air-breathing engines in transient modes. The paper presents the results of laboratory-scale experiments on ignition of nonpremixed fuel-air composition in high-speed flow by a near-surface electrical discharge. The experiments were fulfilled under conditions of model supersonic combustor on the plane wall without any mechanical flameholder. The ignition and flameholding of hydrogen-air and ethylene-air compositions were demonstrated for direct fuel injection into the flow at low (T₀ = 300-750 K) gas temperature. The deposited power was W_pl/H_tot < 2%-5% of flow total enthalpy. The power threshold of fuel ignition over the plane wall was measured by variation of power deposition and fuel mass flow rate. The combustion completeness was estimated to be reasonably high, η > 0.9, with both hydrogen and ethylene fuels under optimal conditions.