Quasi-One-Dimensional High-Speed Engine Model with Finite-Rate Chemistry

Abstract

The quasi-one-dimensionalequations of  uid motion are coupled with the equations for Ž nite-rate chemistry to model high-speed engine  owŽ elds. The model was developed for rapid vehicle design and optimization, where a wide range of engine inlet conditionsmay be encountered. Incorporating the timescales of fuel mixing and ignition are crucial for accurate prediction of combustor performance, especially for nonhydrogen fuels and off-design conditions (where equilibrium assumptions are invalid). The effects of area change, friction, mass injection, fuel mixing, and heat transfer to the combustor walls are included. The resulting model is compared to experimental results for hydrogen-fueled scramjet engines to demonstrate the ability to predict wall pressure proŽ les and fuel ignitionpoint. Application to a rocket-based combined-cycle engine and a hydrocarbon scramjet missile engine are discussed. The model presented predicts peak pressure and fuel ignition accurately, as well as  owŽ eld pressures in regions where boundary-layer separation is not present.