Numerical study on the flow characteristics and stability in the isolator of rotating detonation ramjet engine by different combustion modes and structure parameters

Abstract

In this paper, numerical simulations are conducted to investigate the effects of the combustion modes and structure parameters of the combustion chamber of a rotating detonation ramjet engine(RDRE) generated within the isolator. The stability of the isolator in the combustion mode as a single or dual wave mode is evaluated. The influence of parameters such as the combustion chamber expansion angle and the outside diameter of combustion chamber is also taken into account. The results show that the propagation of the detonation wave in the combustion chamber in a dual-wave (DW) mode reduces the instability generated by the combustion chamber on the isolator. In the stability model, the fluctuation range of the single-wave (SW) mode accounts for 14.43 % of the total length of the isolator, while it is 4.67 % in the DW mode, which is reduced by 10.97 %. The DW mode is more capable of withstanding changes in the combustion state of the detonation chamber. In the SW mode, the back propagation pressure wave (BPPW) propagates to the inlet of the isolator, while the fluctuation range of the isolator in the DW mode only increases by 29.68 % and still maintains a stable working condition. Changing the length of the isolator and outer diameter of the combustion chamber, the DW mode can also accommodate changes in the combustion chamber structure without affecting the inlet flow status of the isolator.