Numerical Analysis on the Lateral Movement of Three-Dimensional Cellular Flames

Abstract

The lateral movement of three-dimensional (3-D) cellular flames is numerically studied. The numerical model includes compressibility, viscosity, heat conduction, molecular diffusion, chemical reaction, and convection. We superimpose hexagonal disturbances on the plane flames and calculate the evolution of disturbed flames. When the Lewis number is unity, i. e., only the hydrodynamic effect has an influence on the flame instability, stationary cellular flames are formed. When the Lewis number is smaller than unity, i. e., the diffusive-thermal and hydrodynamic effects have an influence, laterally moving cellular flames are obtained. The lateral movement of cellular flames is due to the diffusive-thermal effect. The laterally moving velocity of cells in 3-D flames is larger than that in two-dimensional (2-D) flames. Because, the increase of local temperature at the convex surface in 3-D flames is great compared with that in 2-D flames.