Combustion stabilization based on a center flame strut in a liquid kerosene fueled supersonic combustor

Abstract

A newly designed strut is proposed in this paper for fuel injection and flame holding in a liquid-kerosene-fueled supersonic combustor. The thickness of the strut is 8mm and the front blockage is about 8%. The characteristic of this strut is that extra oxygen can be injected through a set of orifices at the back of the strut, which can change the local flow field structure and ER (Equivalence Ratio). Based on the above mentioned strut, a stable local flame is generated at the back of the strut and the main combustion can be organized around this local fire. Numerical simulation is conducted to compare the local flow field distribution at the back of the strut with/without extra oxygen injection. Experiments are conducted to test the combustion characteristics based on this fuel injection and flame holding strategy. The temperature distribution which can reflect the local flame characteristic has been measured in the experiments conducted under cold incoming supersonic air flow condition. In addition, the overall combustion performance in a full-scale supersonic combustor has been evaluated in the experiments conducted under hot incoming supersonic air flow condition. Results show that this strut strategy is very promising since it can organize stable supersonic combustion at the center of the combustor without any cavity or rearward facing step. Besides that, even with the 8mm thick strut, the combustion can be stable in a wide range of ER from 0.25–1 by using liquid room-temperature kerosene.