The lateral movement of the three-dimensional cellular flame at low Lewis numbers

Abstract

Abstract The lateral movement of the three-dimensional (3-D) cellular flame at low Lewis numbers is numerically investigated. The equation used is the compressible Navier–Stokes equation including a one-step irreversible chemical reaction. We superimpose the hexagonal disturbance with the peculiar wave number on the stationary plane flame and calculate the evolution of the disturbed flame. When the Lewis number is unity, i.e., only the hydrodynamic effect has an influence on the flame instability, the stationary cellular flame is formed. When the Lewis number is lower than unity, i.e., the diffusive-thermal and hydrodynamic effects have an influence, the laterally moving cellular flame is formed. With a decrease in the Lewis number, the laterally moving velocity of the cell increases. The laterally moving velocity of the three-dimensional cellular flame is much larger than that of the two-dimensional (2-D) cellular flame. Because, the increment of local temperature at the convex flame front toward the unburned gas in the three-dimensional flame is great compared with that in the two-dimensional flame.