Quasi-one-dimensional high-speed engine model with finite-rate chemistry

The quasi-one-dimensional equations of fluid motion are coupled with the equations for finite-rate chemistry to model high-speed engine flowfields. The model was developed for rapid vehicle design and optimization, where a wide range of engine inlet conditions may 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 profiles and fuel ignition point. 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 flowfield pressures in regions where boundary-layer separation is not present.