A ghost-fluid method for large-eddy simulations of premixed combustion in complex geometries

In this paper, a new ghost-fluid method for interfaces of finite thickness is described. It allows to compute efficiently turbulent premixed flames with a finite thickness in low-Mach flows. A level set algorithm is used to track accurately the flame and to define the overlapping region where the burned and unburned gases satisfy the jump conditions. These algorithms are combined with a fractional-step method to alleviate the acoustic CFL constraint. The full algorithm is verified for simple flame–vortex interactions and it is validated by computing a turbulent flame anchored by a triangular flame-holder. Finally, the algorithm is applied in the LES of an industrial lean-premixed swirl-burner.