Investigation of the effects of fuel injector locations on ignition and flame stabilization in a kerosene fueled scramjet combustor

The effects of fuel injector locations on ignition and flame stabilization in a kerosene fueled scramjet combustor have been investigated in the present paper. Various measurements are made during the experiments in an attempt to better understand the combustion characteristics, including wall pressure measurements and high speed color flame emission images. The results are obtained under the inflow condition of Ma number 2.0, total pressure 1.0 MPa and total temperature 1100 K which corresponds to Ma 4.5 flight condition. When the pilot hydrogen and kerosene were injected into the combustor from the injector K2 (in the cavity) and K1 (upstream the cavity), respectively, the kerosene could be ignited successfully by a lower equivalence ratio (ER) of pilot hydrogen, but the kerosene flame was blowout after the pilot flame was removed. When the injector locations of pilot hydrogen and kerosene were exchanged, the ER of pilot hydrogen must be increased to achieve successful ignition, the kerosene flame stabilization could be achieved after successful ignition. When the equivalence ratio of kerosene was decreased to 0.13, the lean blowout occurred and flame stabilization could not be achieved after the pilot hydrogen was removed. (C) 2017 Elsevier Masson SAS. All rights reserved.