Coupling dominant surface submodels and complex physical process Computational Fluid Dynamics

Abstract

Many processes in the mineral, power and chemical industries involve simulating combined heat and mass transfer with heterogeneous chemical reactions. While numerical methods and codes for solving heterogeneous reactions involving particles and/or droplets are widely available, numerical methods and codes for solving strongly coupled surface submodels are far less widespread and far less robust. In this paper, a solver for arbitrary heterogeneous chemical reactions is developed and linked to a general purpose CFD code, to solve coupled heat and mass transfer problems with dominant surface reactions. The chemical reaction solver uses the Newton--Raphson technique and LU-decomposition to solve the nonlinear species mass balance equations at the reacting surface. Issues with integrating the chemical reaction solver with the CFD code are discussed and the model is then applied to the simulation of underground coal gasification.