LARGE EDDY SIMULATION OF TURBULENT PREMIXED COMBUSTION USING A MARKER FIELD

Abstract

A new laminar flamelet model is presented for Large Eddy Simulation (LES) of premixed turbulent combustion. The model uses a marker field S ⁺ to capture the flame. Compared to previous work on marker fields, a modification was introduced to simplify the boundary conditions. Although the scalar S ⁺ is smooth in space, it allows describing steep flame fronts. The S ⁺ equation captures the laminar or turbulent flame propagation via a reactive diffusive balance. The present LES model was used to simulate a turbulent premixed flame stabilized behind a sudden expansion. The LES predictions agree well with available experimental data in term of reproducing the time averaged velocity field as well as for capturing the flame dynamics and flame response to a perturbation.

Keywords:

• Flamelet model
• Large Eddy simulation
• Premixed combustion

This work has been supported by the Swedish Energy Agency (STEM) with the program “termiska processer för el production.” The computations were performed at LUNARC (Centre for Scientific and Technical Computing at Lund University) and HPC2N (High Performance Computing Centre North) facilities within the SNAC/SNIC allocation program. The authors want to thank Dr. Markus Klein (TU-Darmstadt, Germany) for kindly providing the code for generating the unsteady inflow conditions.