Research on combustion performance optimization in scramjet combustor with strut/wall combined fuel injection scheme

Abstract

A strut/wall combined fuel injection scheme was experimentally investigated to improve the combustion performance in a flush-wall scramjet combustor fueled with liquid kerosene. A thin strut was adopted as fuel injector and flame holder, and wall injectors were also placed on side wall of the combustor, downstream of the strut. With the injection of pure oxygen through the injectors in the trailing edge of the strut, a stable flame was achieved in the combustor, and the flame interaction characteristics were experimentally investigated. Experiments were conducted at the inlet Mach number of 2.0 with different strut/wall fuel distribution schemes. Flame was divided into two parts, namely the core flame and the wall flame, and interaction mechanism between the two parts was experimentally investigated. Experiment results show that core flame is enhanced with the increasing of fuel equivalence ratio. Core flame propagates to side wall of the combustor to ignite wall fuel, forming a wall flame. Wall flame leads to a thermal chocking downstream of strut to enhance core flame. Combustor performance and flame characteristics are influenced by fuel distribution schemes. The location of wall fuel injectors is also optimized to improve combustion efficiency in this paper. These results in this paper are valuable for the future optimization of combustion organization in scramjet combustor with multi-stages fuel injection scheme.