E125 The Flame Front Shapes of Spherically Propagating Turbulent Premixed Flames and their Variation with Equivalence Ratio

Abstract

Burning velocities and configuration of turbulent propagating flames were investigated for iso-octane/air mixtures at equivalence ratios of 0.8, 1.0 and 1.4. The laser tomography was adopted to obtain the cross-sectional images of turbulent flames. The flame front area was evaluated using the perimeter of the cross-sectional image of turbulent flame. The flame brush thickness was also examined. The normalized perimeter of the cross-sectional turbulent flame image was found not to vary so much with equivalence ratio at a constant turbulence intensity, although the ratio of turbulent burning velocity to unstretched laminar burning velocity increased with equivalence ratio. On the other hand, flame brush thickness seemed to vary slightly with equivalence ratio.