Very-Large Eddy Simulation of Complex Turbulent Flame Based on FGM

Abstract

High fidelity simulation of complex turbulent flame is still challenging from many aspects. The present study aims to make the progress from two aspects. The first one is the turbulence modeling, which is achieved by using the newly developed VLES (Very-Large Eddy Simulation) method. The VLES method is a self-adaptive turbulence modeling method which can resolve the turbulence based on the local mesh resolution and the local turbulence scale information. It evolves smoothly from RANS to DNS with the increase of the mesh resolution. It thus can provide accurate predictions on relatively coarse meshes. The second one is the combustion modeling, which is done by combining the FGM (Flamelet Generated Manifold) method. FGM method is an efficient chemistry reduction technique, which has attracted attentions for the successful applications to various complex combustion systems. The present study thus makes the effort to combine the VLES and FGM methods to model complex turbulent flames. Two test cases are selected, i.e. the classical Sandia D flame and the swirling premixed flame from a single GE LM6000 combustor. The numerical results are compared with available experiments. It is found that the VLES-FGM method can be successfully applied for the high fidelity simulation of the complex test flames. The VLES method has high potentials for turbulent flame simulations.