Simultaneous internal/external flow calculation of a solid fuel ramjet projectile: a design analysis

Abstract

SFRI has been regarded as a prime mode of secondary propulsion which enables the projectile to achieve a higher terminal velocity. Geometry of SFRJ is quite simple due to the lack of turbomachinery that conventional jet engines need. The complete internal/external flow field of an SFRJ-TGTR projectile at a cruising Mach number is calculated by an unstructured triangular compressible RANSE solver. To complete the analysis, single-component fuel combustion is added in the combustor flow calculation. A commercial CFD package is used with structured rectangular meshes for such computation. The results from the two computations are compared with existing computational and experimental data for validation. The design parameters like thrust, total pressure loss, inlet and nozzle efficiencies and drag coefficient are derived from the detailed flowfield data. Different values of cruising Mach number and nozzle throat area have been tried as a preliminary design procedure. Change in the nozzle throat area directly affects the inlet flow, because the internal flow is mostly subsonic and is linked directly to the nozzle flow.