PTV Processing Technique Considering Relative Position of Velocity Data to Deforming Boundaries (Keynote Paper)

In this paper, a post-processing technique for PTV measurement of flow around a deforming object is proposed. In general PTV, a position of velocity vector is defined as the midpoint of a tracer particle’s displacement obtained by two sequential images. This is because this velocity vector is close to the tangent vector of the path line. In this case, however, position of the object boundary at the middle time between two sequential PIV images must be interpolated. In this paper, a technique using three-frame images and Eulerian averaging in order to obtain velocity distribution on the regular grid points is proposed and evaluated. As the result, it is found that smooth and correct velocity distribution on the boundary of a bubble is obtained by the present approach.