Influence of multi-strut interaction on flame propagation and combustion performance in a large aspect ratio combustor

Abstract

The flame propagation characteristics and combustion performance of the multi-strut-equipped supersonic combustor with a large aspect ratio fueled by liquid kerosene were observed to deepen understanding of the combustion characteristics. Some numerical simulations and experiments have been carried out at the condition of Tt=1680 K, Pt=1.64 MPa, and Ma=2.7. The fuel distribution under different injection modes was analyzed, and it was found that the fuel mixing efficiency was 28.7% under the single-strut injection method. As the number of injection struts increased to 5, the fuel mixing efficiency improved to 53.8%. The interaction between the ignition strut flame and the injection strut flame was discussed. The results indicated that the fuel injected by the fuel injection strut could be ignited under a high-intensity ignition flame, and the ignition strut flame was promoted by the injection strut flame. The flame characteristics under different installation widths of the injection struts were analyzed. The fuel injected by the injection strut could not be ignited when the large installation width was 40.5 mm. A method to increase the flame spread width without the addition of extra energy was proposed based on the flame propagation characteristics. This method not only increases the flame width but also widens the combustion boundary. The principle of this method was revealed by analyzing the characteristics of the cross-flame. The results of this paper are beneficial for the future performance optimization of large aspect ratio combustors using liquid hydrocarbon fuel.