Combustion LES Software For Improved Emissions Predictions of High Performance Gas Turbine Combustors

"Turbulent-combustion emissions modeling (NOx, CO, UHC and smoke) of military gas turbine combustors is a very difficult challenge. Although current RANS steady-state modeling can provide trends, it fails to give quantitatively - accurate predictions ofemissions. A more accurate way to model combustor flows, and proposed for development in this SBIR, is combustion Large Eddy Simulation (LES). Practical combustion LES calculations (1-2 million cells) can now be performed in ten days on a Beowulf PCcluster, and in five years, the run time will be less than a day as computers become substantially faster. We will start with an existing combustion LES code under development the past two years. In Phase I, a ten species mechanism, that includes JP8 fuel oxidation coupled with CO and NOx chemistry, will be used. We will model subgrid turbulence-combustioninteraction with the Conditional Moment Closure (CMC) model developed by Stanford University. The Rolls-Royce AE3007 combustor will be modeled, and experimental data (exit temperature profile, CO, and NOx) will be compared with predictions. In Phase II,the software will be improved, including development of a more detailed chemical mechanism for accurate computation of unburned hydrocarbons and smoke. The final code will be applied to the Rolls-Royce JSF F136 combustor, and modifications to reduceemissions will be assessed. The combustion LES software developed in this SBIR will b