The effect of Bypass Air Injection Geometry in a Boron-Loaded Solid Fuel Ramjet

The solid-fuel ramjet (SFRJ) is a propulsion system optimized for supersonic flight, offering high specific impulse and energy density. Boron-based fuels provide a significant energetic advantage over conventional hydrocarbon fuels; however, particle ignition and combustion are challenged by an initial oxide layer and limited residence time in the combustor.

This research primarily studied the influence of bypass air injection configuration on combustion efficiency, while also considering additional contributing factors. A parametric investigation was conducted using computational fluid dynamics (CFD) simulations (ANSYS Fluent), focusing on the mixing chamber region. Emphasis was placed on evaluating the impact of tangential bypass air injection on flow dynamics and the overall engine performance. The study further explored the effects of bypass and momentum ratios, injection angles, boron particle size, and boron content in the fuel. The study aimed to identify the injection strategy and configuration that optimize boron particle combustion and overall combustion efficiency under the SFRJ operating conditions.