LARGE-SCALE PARTICLE IMAGE VELOCIMETRY FOR FLOW-ANALYSIS IN HYDRAULICENGINEERING APPLICATIONS

Large-Scale Particle Image Velocimetry (LSPIV), as presented herein, i s an extension of particle image velocimetry (PIV), which aims at prov iding velocity fields spanning large flow areas in laboratory or field conditions. Additional data, such as mappings of large-scale flow str uctures and discharges are readily obtainable using LSPIV. While the i mage- and data-processing algorithms are similar to conventional PIV, adjustments are required for illumination, seeding procedures, and pre -processing of the recorded images. This paper describes the implement ation of video-based LSPIV in three hydraulic engineering applications covering surfaces from 4 m(2) to 45,000 m(2). These applications are: gas-transfer processes downstream a model spillway, ice conveyance th rough a model river confluence, and flood plain flow in a full-scale r iver. The special problems encountered in each of these experiments, a s well as the selection and adjustments of the parameters to properly solve them, are examined. LSPIV has proven to be a reliable, flexible, and economically efficient flow diagnostic tool that can be employed successfully in the surveillance planning, design, hazard warning, ope ration, and management in water-related activities.