Modeling method of RBCC engine based on three-dimensional CFD

RBCC engine can operate at multi-modes((inject-, ramjet, scramjet and rocket as well)) and adapt to a wide flight envelope, which is mainly resulted from the shearing action between the primary rocket plume and inlet air varies drastically. The cross-section along the flow path varies a lot for mounting the rocket, stabling the burning and accelerating the gases, and meanwhile the fuel is injected changing in both the amounts and the positions as well according to the operating mode. The complex driving-forces result in the difficulties to develop the performance model and to control RBCC. Based on the ground test configuration of RBCC engine, the characteristics of flow field and state variables of RBCC engine were studied by using three-dimensional CFD, and then a state variable model with the method of CFD and linear fitting was developed. It is shown that the state variable model matches up with CFD calculations. Studies also show that modeling accuracy can be improved by increasing the data points till 20.