Three-Dimensional Velocity and Vorticity Measuring and Image Analysis Techniques

The contents of this volume reflect to a large extent the efforts made by a group of Institutes at the ETH Zürich to develop new techniques for measurements of flows in fluids in the last decade. The motivation came from the study of tr~sport and mixing processes in natural and industrial systems. One of the characteristic properties of turbulence is its high mixing efficiency. The techniques developed are therefore suitable, although not exclusively, for turbulence measurements. They can be subdivided into point-measurements and field-measurements. The aim of the point-measurements developed is to determine the three components of the velocity and all their first derivatives with good temporal resolution and accuracy in turbulent flows. The old and weIl established method of hot-wire anemometry was used for this purpose. One of the main achievements in this context is the construction of miniature multi-wire probes. This technique was introduced to the Institute of Hydromechanics and Water Resources Management of ETH Zürich by Profs. A. Tsinober and E. Kit from Tel-Aviv University. This was made possible by the generous financial support by ETH, for which I would like to express my gratitude on this occasion. In addition, Dr. F.E. Joergensen from DANTEC contributed an example of recent developments in the hardware ofConstant Temperature Anemometry (CTA), for which I am very thankful.

Contenu
Determination of 3-D Velocity and Vorticity Vectors in Turbulent Flows by Multi-Hot-Wire Anemometry.- The Multi channel Constant Temperature Anemometer.- Particle Image Velocimetry: A New Approach in Experimental Fluid Research.- Real-Time Signal Processing in Particle Image Velocimetry.- Investigation of Unsteady Flow Fields in Wind Tunnels by Means of Particle Image Velocimetry.- Three-Dimensional Particle Velocimetry.- Particle Tracking Velocimetry (PTV), Basic Concepts.- Videogrammetry: Methodology and PTV/LIF Applications.- Contributions of Digital Photogrammetry to 3-D PTV.- Particle Tracking in Three-Dimensional Space.- Establishment of a Videogrammetric PTV System.- Laser Induced Fluorescence Velocimetry , Basic Concepts.- Adaptive Least-Squares-Matching for Accurate Tracking of Patterns in Voxel Data Sequences.- Establishment of a Tomographic Laser Induced Fluorescence System.- Application and Performance of LIF-Velocimetry.