Simulation of Reacting Spray in a Multi-Point Lean Direct Injection Combustor

摘要

This paper investigates the reacting spray phenomena in a multi-point lean direct injection (MPLDI) combustor to characterize the effects of highly swirling air flows on spray combustion. The Reynolds-averaged Navier Stokes (RANS) code is applied to simulate the turbulent, reacting, and swirling flow associated with the combustor. For the liquid spray modeling, several spray sub-models are used. Properties of both the gas and liquid phases are analyzed. The reacting flow simulations show short flames emanating from the individual injectors, uniformly low temperature distribution inside the combustor, and a uniform temperature profile at the chamber exit. With an increase in air flow velocity, the flow field becomes highly strained at the injector exits where the fuel and air streams mix and at the interfaces of the neighboring swirlers, allowing the mixing process to speed up. Overall, the computational results are able to capture and explain some of the fundamental features of the MPLDI combustor, such as the fuel-air mixing, drop size distribution, drop vaporization, and spray combustion process.