A Development of a Rearrangement Method Using the Velocity Gradient Tensors for PTV

Abstract

The authors developed the velocity gradient tensor method (VGT) which was a PTV algorithm for measuring flow field as reported in a previous paper. When the VGT method is used, both the velocity vector and velocity gradient tensor can be obtained at each particle point. The purpose of this study is to propose a new technique for post-processing using the velocity gradient tensor in order to make a rearrangement of velocity vectors at particle points into those at grid points with a high spatial resolution. The per-formance of the processing method is examined by the vortex flow. It is made clear that the present method has high accuracy compared to conventional interpolation methods.