Buoyancy influence on wrinkled premixed V-flames

In drop tower experiments, a series of methane-air premixed V-flames of wrinkled flame fronts were observed in both normal gravity and microgravity conditions by the use of OH-PLIF (Planer laser induced fluorescence for OH- radicals) to study the buoyancy influence. For each flame, a high-speed intensified CCD camera recorded a large number of OH-PLIF images of the instantaneous flame fronts in both normal gravity and microgravity conditions. To evaluate the buoyancy influence, a computer code series for image processing was developed and the structure of each flame was extracted from the OH-PLIF images by performing statistical calculation. The result shows that buoyancy influences on one hand the mean flow field of the flames, on the other hand the propagation of the wrinkled flame fronts. It was also found that to a certain extent, the buoyancy influence correlates to the turbulence intensity and the laminar flame speed of the pre-mixture.