Inlet buzz and combustion oscillation in a liquid-fueled ramjet engine

The purpose of this research is to investigate inlet buzz and combustion oscillation in an axisymmetric ramjet engine with spray injection and combustion. In a ramjet engine, inlet buzz during subcritical operation is related to large pressure oscillations, combustion instability, engine surge, and thrust loss, among other factors. The physical model of concern here includes the entire engine flow path, extending from the leading edge of the inlet center- body through the exhaust nozzle. Unified unsteady numerical analysis is used to study the relationship between inlet buzz and Inlet buzz which is considered spray injection and combustion. The theoretical formulation is based on Favre-averaged conservation equations of mass, momentum, energy, and species concentration. This formulation accommodates finite-rate chemical kinetics and variable thermo-physical properties. To take account for the important features over a very wide range of Reynolds number flow, a preconditioning method, a compressible turbulence model, and the low Reynolds number κ-£ model with compressibility correction were applied for precisely predicting the flow structures. To calculate liquid droplet breakup, the TAB (Taylor Analogy Breakup) model was applied and two phase mass transfer was considered by continuum/dispersed phase coupling. A parallel computing scheme using MPI (Massage Passing Interface) library was implemented. The detailed flow structures such as buzz shock train, shock/boundary layer interaction, and flame fluctuation were observed.