Subgrid Modeling for Reacting Large Eddy Simulations

Development of accurate combustion models is needed to aid in the design of improved combustors in both the aircraft and automotive industries. Numerical models capable of providing the necessary information must be able to predict the highly unsteady behavior associated with turbulent-chemistry interactions. One promising approach to investigate flows of practical interest is large-eddy simulation (LES). However, relatively few extensions to reacting flows have been made since additional closure problems arise from combustion-related terms which are difficult to model. One approach to combustion related subgrid closure is the linear-eddy mixing (LEM) model. This model separately treats the physical process of molecular diffusion and turbulent stirring so that an accurate picture of the interaction of the turbulence and the chemistry can be obtained. This paper investigates the LEM model for use in LES simulations of diffusion flames