Theoretical nderstanding of the effects of high-density energetic particles on the ramjet performance

In solid fuel ramjet engines, performance is significantly influenced by both the fuel's heat of reaction and density, which are critical for optimizing specific impulse and density-specific impulse. The density-specific impulse is determined by multiplying the density of the solid fuel composition by the specific impulse, thus accounting not only for the fuel's performance but also for volumetric considerations, which in turn affect the vehicle's shape. It is well known that vehicle shape plays a crucial role in determining the lift to drag ratio (L/D) and, consequently, overall vehicle performance. For example, specific impulse increases proportionally to the square root of the flame temperature or heat release, while density-specific impulse increases linearly with fuel density. Fuel density can be enhanced by incorporating additives and energetic particles into the fuel matrix, while flame temperature can be increased by adding additives such as CuO and PTFE during combustion. The aim of this work is to enhance the density-specific impulse of ramjet solid fuels by incorporating high-energy metals such as aluminum (Al), boron (B), and magnesium (Mg) into an HTPB-based fuel, and to improve specific impulse by adding CuO and PTFE. The performance of these solid fuels is assessed using the NASA CEA code, and this paper presents a detailed comparison of the resulting fuel compositions and their respective performance characteristics.