rans simulation of turbulent diffusive combustion using open foam

Schemes to write the flow equations in discreet form, solution solvers, pre and post data processingutilities provided by openfoam libraries, are used to build a finite volume executable for simulating alow speed, turbulent and rate controlled diffusive ch4-air combustion. unsteady favre’s averagedturbulent conservation equations (total mass, momentum, energy and species mass fractions), areused to describe the combustion gas dynamics, and to handle turbulence a modified k-e model isapplied. several global kinetic mechanisms, one step, two and four steps have been considered todescribe the oxidation process of ch4 in a free jet type flame. the interaction between chemistryand turbulence, is modeled according to the partially stirred reactor (pasr) concept. to improveconvergence and accuracy in solving low speed fluid dynamic equations, a pressure implicit withsplitting of operators (piso) technique extended to cover high temperature flows, is utilized. theexponential dependence of the chemical kinetics from temperature, makes stiffs the ode’s neededto determine source average values with which the species conservation equations are solved. todeal with the stiffness issue, openfoam provides numerical schemes that guaranties the stabilityof the computation. comparisons between results of numerical simulations and experimental dataobtained with the benchmark known as flame “d”, are presented.