Visualization and Measurement of Velocity Distributions of Periodical Vortex Shedding from Columns by means of Speckle Method

摘要

The method of speckle photography (the speckle method) is one of the most useful methods of measurement of velocity distribution at the same instant in a two-dimensional flow field. Many investigations on techniques and accuracy of this method and on applications are performing by many reserchers. In the present paper, the speckle method using an incoherent light source (the white-light speckle method) is applied to visualization and measurement of velocity distribution in an unsteady flow field produced by periodical vortex shedding from a triangular column put into pulsating flow in a water channel.