Numerical study on the hydrodynamic instability of high-temperature premixed flames: Formation of three-dimensional cellular fronts

The formation of three-dimensional cellular fronts in high-temperature premixed flames at the Lewis number of unity was numerically studied, under the conditions of constant burned-gas temperature. On a planar flame, we superimposed a disturbance with the critical wavelength which was obtained from the dispersion relation. The superimposed disturbance evolved, and a cellular-shaped flame front formed. The shape of cellular fronts became smoother as the unburned-gas temperature became higher, even though the growth rate increased. The burning velocity of a cellular flame normalized by that of a planar flame decreased, which was due to the weakness of thermal-expansion effects.