A consistent-splitting approach to computing stiff steady-state reacting flows with adaptive chemistry

摘要

Splitting techniques have been used extensively for computing reacting flows with detailed chemistry. Nevertheless, there are still some open questions with respect to efficiency and the error introduced by splitting. In this paper, the accuracy and effectiveness of split-operator methods for computing steady-state reacting flows are determined. A fully coupled scheme is described together with two splitting schemes: a standard Strang-splitting scheme and a consistent-splitting scheme, all with implicit transport computations. The effect of splitting errors on the convergence and solution accuracy is investigated analytically using a one-dimensional scalar equation. The accuracy with respect to the original discretized equations is tested for an H_2/O_2 burner flame. Finally, consistent splitting is combined with an adaptive chemistry approach to compute three partially premixed laminar methane flames using detailed chemistry (217 reactions). The calculations confirm that HCO radical concentration is an excellent surrogate for heat release rate.