FEM-SIMULATION OF LAMINAR FLAME PROPAGATION II: TWIN AND TRIPLE FLAMES IN COUNTERFLOW

ABSTRACT

In a low-Mach-number counterflow geometry, steadily propagating twin and triple flames are investigated. A complete numerical model of such flames is presented including a Galilean-like transformation to achieve steadiness of the flames in a moving frame of reference. The model is based on a similarity transformation of the fundamental conservation Equations in primitive variables, which transforms the inherently three-dimentional problem to two space dimensions. Suitable boundary conditions are derived employing potential theory. The governing Equations are discretized by a finite element method on an unstructured triangulized grid. Employing a local adaptive mesh-refinement procedure, for H₂‒O₂ systems with both a global one-step model and a detailed mechanism of elementary reactions, numerical solutions have been obtained.

Keywords:

• laminar flame
• twin flame
• triple flame
• counterflow
• chemically reactive flow
• numerical simulation
• finite elements
• Galilean transformation

Acknowledgments

The authors are grateful to Professor A. Liñán for hosting B.M. and for helpful discussions on the boundary conditions.