Very Large Eddy Simulation of Swirling Premixed Combustor Based on FGM

In order to develop high fidelity and efficient numerical methods for premixed combustion simulations in complex engineering applications such as aero-engine combustor, a numerical approach is proposed based on the Flamelet Generated Manifolds (FGM), which is one of the detailed chemistry tabulation methods, coupled with the Very Large Eddy Simulation (VLES) method. It is then applied to study the swirling premixed flame in a simplified combustor, i.e. GE LM6000 and the simulation results are compared with the experimental data in detail. The results indicate that the present VLES-FGM method can accurately predict the velocity and temperature flow fields in the swirling premixed combustor. To further simulate the combustion process in real aero-engine working conditions, the periodic boundary condition is applied to imitate the boundary conditions in the annular combustor. The results show that the recirculation zone in the periodic combustor predicted by VLES-FGM is smaller than that in the wall confined combustor. Moreover, the temperature flow field in the wall confined combustor shows a significant neck flow structure and the high temperature zone downstream the combustor is more evenly distributed. The present study indicates that the adaptive turbulence modeling method, i.e. VLES, coupled with FGM combustion model has high potential to simulate the swirling premixed combustion in complex aero-engine applications. © 2021, Science Press. All right reserved.