Powder fuel transport process and mixing characteristics in cavity-based supersonic combustor with different injection schemes

Abstract

The transport process and mixing characteristics of powder fuel in the supersonic airflow are essential for the working performance of a powder fueled scramjet. In the current investigation, the effect of different injection schemes on the powder fuel jet flow field and mixing characteristics are numerically studied in the cavity-based supersonic combustion chamber. The simulation is employed by the Eulerian-Lagrangian scheme coupling with the gas-solid two-phase Reynolds-average Navier-Stokes (RANS) method. Verification of numerical method and grid-independent is conducted firstly, which demonstrated the correctness and credibility of the method in this research. The results show that the powder fuel injection into the combustor induces typical gas-solid two-phase jet flow characteristics. With respect to the fuel injection schemes upstream of the cavity, the powder fuel moves across the cavity section and is continuously mixed with the mainstream along the flow direction. The mixing intensity in the combustion chamber is associated with the motion and distribution patterns of the particles. For the cavity internal fuel injection scheme, the particles are mainly distributed inside the cavity. Some of the particles can be coiled and sucked into the supersonic mainstream. The cavity shear layer and expansion section near the bottom wall is the main region with better mixing performance.