Influence of the fuel jet injection angle on the combustion process of a gel scramjet

Abstract

Boron-containing gel propellants have high-energy densities and controllable injection characteristics, can significantly improve ramjet performance, and present a new direction for hypersonic vehicle development. To address the performance optimization problem of boron-containing gel scramjet engines, this study combines supersonic turbulence combustion interaction equations and the multiphase flow equations to make use of a combustion flow simulation method for the internal flow fields of boron particle gel ramjet engines at a multi-grid scale. Numerical simulations of the internal flow field of a combustion chamber at different fuel injection angles were conducted. The results indicated that as the fuel injection angle increased, the fuel jet penetration effect was enhanced, and the obstruction effect on the supersonic airflow became more pronounced. When the injection angle exceeds 35°, the supersonic airflow flows along the lower wall at a particular deflection angle. As the angle increases, the main combustion region of the fuel moves from the end of the combustion chamber to the downstream cavity. When the fuel injection angle reaches 80°, the temperature increase efficiency reaches its optimal value of 71 %. The research findings provide an optimized design solution for boron-containing gel propellant scramjet engines.