Velocity and Temperature Fluctuations in a Flat Plate Boundary Layer Diffusion Flame

Measurements of mean value and turbulent intensity of fluctuating velocity as well as fluctuating temperature have been made on a turbulent boundary layer diffusion flame over a flat plate. Results show that the turbulence production occurs along the flame zone. This behavior is reflected in the high gradient of mean velocity. That is, the variation of velocity fluctuation due to the flame is primarily attributed to the variation of the mean velocity profile. Therefore it can be concluded that an ordinary shear-generated turbulence plays an important role on turbulence in the whole region of the boundary layer. Results also show that the temperature fluctuation is attributed to the gradient of mean temperature in a turbulent flow. At the same time, the temperature fluctuation in the air stream side is intensified due to the penetration of room temperature gases into the burnt gas region.