Simulation and analysis of an aero-engine combustor with a slinger fuel injection system

The use of Computational Fluid Dynamics (CFD) is now central to the design process of aero-engine combustors, enabling optimal, safe and stable operation, increased efficiencies, and the reduction of pollutant emission. To benefit maximally from the use of CFD it is essential to account for the relevant physical phenomena, in particular the fuel spray breakup and its evaporation. Different strategies for modelling the injection of fuel spray are applied - in the simplest approach the fuel is assumed to be gaseous upon injection, in the most advanced approach the fuel is modelled, using a Lagrangian-Eulerian approach, as a liquid spray which breaks up, evaporates and eventually burns inside the combustion chamber. The effects of the various modelling strategies on the flow, temperature, and compositional fields are investigated. The radial distribution of the simulated temperature field is compared to experimental data, demonstrating that acceptable accuracy is only achieved when the fuel is modelled as a liquid spray and a two-way momentum coupling between the spray and the gas-phase is accounted for.