Finite Point Low Mach Number Algorithm for Unsteady Nonisothermal Flows Application to the Study of Reactive Flow Past a Thin Catalytic Wire

Abstract

A numerical algorithm is presented for the solution of low Mach number unsteady nonisothermal flows at moderate Reynolds numbers (Re ∼ 100) with variable transport properties. The low Mach number limit is approached by using a relaxation method of the pseudo-compressibility type that has proved to be numerically robust and accurate enough to be used in industrial applications. Time integration is explicit and space integration is based on a finite point approach. Solver validation includes a sensitivity analysis and a comparison with previously published results concerning the flow around heated cylinders at different Re and temperature loadings. Then, the solver is applied to calculate the flow of a reacting mixture past a thin catalytic wire, a problem of interest for power MEMS design (micro catalytic reactors), aiming to determine the chemical-to-thermal energy conversion rate at the catalytic wire.

This collaborative research was supported by the Spanish Ministry of Education and Science (MEC) under projects DPI2005-05572 and ENE2008-06683-C03-02, and by the Comunidad de Madrid under project S-505/ENE/0229. The authors are indebted to Prof. A. Liñán at the Universidad Politécnica de Madrid and Prof. A. L. Sánchez at Universidad Carlos III de Madrid for helpful discussions.