A Comparison of Cold and Reacting Flows Around a Bluff-Body Flame Stabilizer

A confined oblique flame anchored on a bluff object was considered in a homogeneous propane/air mixture. A laser velocimeter employing a unique single-particle processor was used to quantify the turbulence velocity as well as spectrum. The results with combustion presented a striking contrast to the corresponding cold flow data. A major conclusion of the work is that the apparent suppression of turbulence observed in the separated combustion flow may be attributed to the significant dilatation effect by heat release in sheared flow regions. No vortex shedding was detected, and the negative production zone of turbulence energy was not observed. The turbulence structure was significantly distorted at the visible flame location.