Numerical simulation of flame propagation characteristics in a strut-equipped supersonic combustor fueled with liquid kerosene

The flame propagation characteristics and multiple influencing factors of the flame width of the strut-equipped supersonic combustor fueled by liquid kerosene were observed to deepen understanding of the combustion characteristics. A series of numerical simulations using a multi-step reaction combustion mechanism were performed under the condition of T_t= 1680K, P_t = 1.64Mpa, and Ma = 2.7. The flame propagation process at the tail of the strut could be divided into three regions by the change of flame width: initial propagation region, contraction region, and re-propagation region. The fitting formulas of flame width in the initial propagation zone and re-propagation zone were obtained. The mechanism of igniter power on flame width was revealed, which broadens the propagation width of the flame by increasing the degree of local thermal choking and the reactivity of particles. The flame propagation processes under different number of struts were also studied. Under the multi-strut injection method, a cross flame zone was generated outside the center flame, and the flame propagation width was increased significantly. The main driving force of flame propagation in these two flame regions was obtained. The results of this paper are beneficial for the future performance optimization of the supersonic combustors using liquid kerosene fuel.