Willneff, Lüthi 1 PARTICLE TRACKING VELOCIMETRY MEASUREMENTS FOR LAGRANGIAN ANALYSIS OF TURBULENT FLOWS

Abstract

3D Particle Tracking Velocimetry offers a flexible technique for the determination of velocity fields in flows. At ETH Zürich an operational and reliable system was developed at the Institute of Geodesy and Photogrammetry and was used for manifold applications in the past decade. In cooperation with the Institute of Hydromechanics and Water Resources Management further progress has been achieved in the improvement of the existing hard- and software solutions. Regarding the improvements of the hardware setup, the image acquisition with an online digitization was upgraded from a recording rate of ¢¤£¤¥§¦ to a ¨ Further progress was also made on the software implementation. A new spatio-temporal matching algorithm was developed, implemented and tested. The most important result of this method is a substantial increase of the tracking rate in 3D-PTV. This is of importance mainly in the context of a Lagrangian analysis of particle trajectories. The hard- and software improvements of the 3D-PTV method are described in this paper. Investigations about velocity derivatives could benefit from the improvements of both- the software as well as the hardware- solutions. The paper will show the contribution of the PTV method for the Langragian analysis of turbulent flows