Chen, Kaiwei, authorEttema, Robert, advisorThornton, Christopher, committee memberNelson, Peter, committee memberLanders, Stuart, committee member2018-06-122018-06-122018https://hdl.handle.net/10217/189265Large-scale particle image velocimetry (LSPIV) is a nonintrusive technique used to measure free-surface velocities of water flow in a manner that produces a two-dimensional vector field of flow velocity. LSPIV is gradually becoming quite widely used as a technique for measuring flow velocities in a range of flow areas. This study used readily available material and devices, and software, to apply LSPIV to flow fields in two laboratory flumes at the Hydraulics Laboratory of Colorado State University; LSPIV had not been used in this laboratory before this study. The applications used pieces of paper as tracer floats in the flow field, and employed a standard iPhone 6s to record video of the tracers moving in the flow field. The video record of tracer movements was then analyzed using Fudaa LSPIV software and Tecplot 360 software to calculate and present the flow velocity data. The applications demonstrated the utility of the LSPIV technique for determining the free-surface flow patterns, and their variations, in experiments done at the Hydraulics Laboratory. Additionally, this study examined the relationship between the tracer size and LSPIV accuracy with the objective of identifying an optimal width of tracer relative to the width of the flow field and its features. Five sizes of tracer were used in measuring the water-surface flow field through a series of contractions and expansions. It was found that the best tracer size is about from 3.80% to 6.33% of the wide of the channel.born digitalmasters thesesengCopyright and other restrictions may apply. User is responsible for compliance with all applicable laws. For information about copyright law, please see https://libguides.colostate.edu/copyright.bendway weirtracer sizeLSPIVaccuracyText