Large-eddy simulation of two-phase reacting flows and combustion performance in model combustor

Instantaneous gas-liquid two-phase turbulent combustion flows in model combustor were computed by using an Eulerian-Lagrangian two phase large-eddy simulation (LES) approach in three-dimensional arbitrary curvilinear coordinates,and combustion performance was estimated by an empirical-analytical design methodology.The k-equation subgrid scale model was used to calculate the subgrid eddy viscosity,and the EBU (eddy-break-up) subgrid scale combustion model was applied to predict the chemical reaction rate.The gas phase governing equations were solved by SIMPLE (semi-implicit method for pressure-linked equations) algorithm in non-staggered grid system,and a stochastic separated flow formulation was employed to track the droplet trajectory velocities,sizes and temperature history by Lagrangian equations of motion and thermal balance.Numerical simulation results were in reasonable agreement with the instantaneous velocity by particle image velocimetry (PIV) system and temperature measurements at the exit plane.It shows that in an arbitrary curvilinear coordinates,the Eulerian-Lagrangian two phase LES formulation can be used to investigate turbulent two-phase reacting flows and combustion process in model combustor,and combustion performance results are in reasonable agreement with the measurement results.It shows that the empirical-analytical design methodology can be applied to predict the combustion performance in gas turbine combustors,especially for pollution emissions,and it provides a useful tool for designing advanced gas turbine combustor of low emissions of pollutant and high performance.