A note on the numerical simulation of Kleijn's benchmark problem

In this study various numerical schemes for transient simulations of 2D laminar reacting gas flows, as typically found in Chemical Vapor Deposition (CVD) reactors, are proposed and compared. These systems are generally modeled by means of many stiffly coupled elementary gas phase reactions between a large number of reactants and intermediate species. The purpose of this study is to develop robust and efficient solvers for the stiff reaction system, where as a first approach the velocity and temperature fields are assumed to be given. Furhtermore, we neglect thermal diffusion (Soret effect). In this paper we mainly focus on the performance of different time integration methods, and their properties to successfully solve the transient problem. Besides stability, which is important due to the stiffness of the problem, the preservation of on-negativity of the species is crucial. It appears that this extra condition on time integration methods is much more restrictive towards the time-step than stability.