Abstract
The purpose of this paper is to investigate the stress at the separation point in laminar flow from an analysis of velocity distribution obtained by PIV method. For the purpose of measurement of fluid velocity near the wall, density and size of smoke particle in air were better than those of additives in mineral oil or of scattering particles seeded in tap water. The fluid on the stream line starting from the point of separation accelerated in a narrow area with large tensile and shearing stress. This result means that huge stress is produced around at the point of separation by flow.
