关键词: 湍流;分离流;附面层;激光测速仪;扩压器

Abstract: The separating flow in a turbulent boundary layer was surveyed in a 2-D curved-wall diffuser by employing 2-D laser Doppler vel-ometer. Mean velocities, Reynolds stresses, mean flow angles and upstr-eam-downstream intermittencies were obtained. The error analysis of experimental results was also made and the uncertainty are presented, experimental results showed that, the intermittent instantameous detachment occurs at the point with the maximum of the normal pressure gradient in the boundary layer. Schofields velocity scale and length scale are adapted to form a new velocity similarity. Mean flow angles are linearly related to the up-stream-downstream intermittencies.

Key words: Turbulent flow;Separating flow;Boundary layer;Laser Doppler velocimeter;Diffuser