Numerical simulation of premixed combustion using an enriched finite element method

In this paper we present a novel discretization technique for the simulation of premixed combustion based on a locally enriched Finite Element Method (FEM). Use is made of the G-function approach to premixed combustion in which the domain is divided into two parts, one part containing the burned and another containing the unburned gases. A level-set or G-function is used to define the flame interface separating the burned from the unburned gases. The eXtended Finite Element Method (X-FEM) is employed which allows for velocity and pressure fields that are discontinuous across the flame interface. Lagrange multipliers are used to enforce the correct jump conditions over the embedded flame interface. A persisting problem with the use of Lagrange multipliers in X-FEM has been the proper discretization of the Lagrange multipliers. In this paper the distributed Lagrange multiplier technique is adopted, which can also be conveniently used for three-dimensional problems. We will show that a small modification of the interface is required to ensure a unique solution. Finally, results are presented from the application of the method to the problems of moving flame fronts, the Darrieus Landau instability and a piloted Bunsen burner flame.     «

In this paper we present a novel discretization technique for the simulation of premixed combustion based on a locally enriched Finite Element Method (FEM). Use is made of the G-function approach to premixed combustion in which the domain is divided into two parts, one part containing the burned and another containing the unburned gases. A level-set or G-function is used to define the flame interface separating the burned from the unburned gases. The eXtended Finite Element Method (X-FEM) is emp...     »