Unified Analysis of Internal Flowfield in an Integrated Rocket Ramjet Engine. I: Transition from Rocket Booster to Ramjet Sustainer

A comprehensive numerical analysis was conducted to study the internal flow development in an integrated rocket-ramjet (IRR) propulsion system. The study consists of two parts: transition from the rocket booster to the ramjet sustainer and combustion dynamics during ramjet operation. The physical model of concern includes the entire IRR flow path, extending from the leading edge of the inlet center body through the exhaust nozzle. The theoretical formulation is based on the Farve-averaged conservation equations of mass, momentum, energy, and species concentration in axisymmetric coordinates and accommodates finite-rate chemical kinetics and variable thermophysical properties. Turbulence closure is achieved using a low-Reynolds-number k-ɛ two-equation model. The governing equations are solved numerically by means of a finite-volume preconditioned flux-differencing scheme capable of treating a chemically reacting flow over a wide range of Mach numbers. Various important physiochemical processes involved in the transition from the booster to the sustainer phase are investigated systemically. Emphasis is placed on the flow interactions between the inlet diffuser and combustor. The effects of operation timing on the flow evolution, fuel spread, ignition, and flame development are studied.DOI: 10.1061/(ASCE)AS.1943-5525.0000255.© 2014 American Society