A Discrete Dynamical System Low-Dimensional Model of Homogeneous and Heterogeneous H_2-O_2 Reactions in a Turbulent Flow Field

摘要

We derive a discrete dynamical system (DDS) that models both homogeneous and heterogeneous H_2- O_2 reactions near, and on, a catalytic surface employing a technique introduced by McDonough and Huang (Int. J. Numer. Meth. Fluids 44, 545-578,2004). This approach utilizes a Galerkin procedure to obtain a low-dimensional dynamical system from the full governing equations. This is discretized via standard numerical integrators to produce an easily evaluated DDS that can be shown to be analogous to a pseudodifferential operator of the original system of partial differential equations and thus provides a useful contribution to subgrid-scale models for large-eddy simulation. The homogeneous reactions are modeled with a simple six-step mechanism previously studied by McDonough and Zhang (AIAA Fluid Dynamics Conference Paper #2002-3172, 2002), and the heterogeneous mechanism is a subset of that of Andrae and Bjoernbom (AlChE J. 46, 1454-1460, 2000). We describe details of modeling homogeneous-heterogeneous reaction interactions and present results in terms of time series of turbulent velocity components, species concentrations and temperature for both near-wall and fully-turbulent boundary-layer flow fields.