Large Eddy Simulation of turbulent combustion flows in gas-turbine combustors

This research investigates turbulent combustion model based on a multiple-scalar flamelet approach coupling the two concepts of premixed and non-premixed and non-premixed flames expressed by the conservative scalar of mixture fraction and the levelset function(G-equation) of premixed flame front, respectively. A new conceptual G-equation is developed for capturing the complicated non-premixed flame propagation, which can directly model not only the flame speed and also the flame thickness. For applying to real scale gas-turbine combustor, the large eddy simulation (LES) is introduced to simulate the unsteady phenomena of turbulent combustion. The new flamelet model can be applied in the unsteady simulation on the practical unstructured grid system without any additional numerical viscosity or re-initialization treatment. Industrial applications to different types of gas-turbine combustors are introduced. In any case, premixed or partial premixed turbulent flames by the complex burner system of industrial combustor can be reasonably captured by the new flamelet approach without any additional numerical procedure or artificial diffusive scheme.