Effect of fuel injection position on scramjet mode of RBCC engine

In order to validate the adaptability and obtain good combustion performance of rectangular RBCC engine in scramjet mode, numerical simulation was used. Second-order discretization of Total-Variation-Diminishing (TVD) method and twelve-step reduced chemical kinetic model were used during simulation. The cold and hot flow field of engine were analyzed, and the effect of variation of injection position in scramjet mode on RBCC engine's combustion performance was compared. Results show that: 1. the RBCC engine operating with ethylene as fuel could obtain high combustion pressure and combustion performance; 2. better combustion efficiency and engine performance can be achieved when fuel was injected upstream of the area between the strut and cavity. The thrust could gain a 9% promotion when injecting fuel from appropriate position; 3. the low speed and high temperature recirculation region downstream the strut provides a better heat release for the fuel.