Low-cost surface particle image velocimetry for hydraulic model studies

Abstract

An application of a large-scale PIV technique on a scaled hydraulic model of a hydroelectric powerplant was performed. A detailed study regarding the relationship between the tracer size (paper confetti) and the spatial resolution settings of the statistical correlation program was carried out. The validated parameters and operational procedures were used for the flow characterization in two areas: the spillway approaching area and the tailrace channel. The larger tracer (10 mm diameter) performed better. The manual particle seeding showed to produce negative bias effects in velocity measurements, due to particle agglomeration. The low-cost measurements resulted in velocity field information of a resurgence flow in the tailrace channel measured with only 10 pairs of images. The study showed, as a proof of concept, that hydraulic model studies could easily be complemented with LS-PIV techniques providing spatial and temporal variations of velocity fields for flow analysis with advantages against intrusive point-based measurement techniques.

KEYWORDS:

• Large-scale PIV
• confetti tracer
• scaled hydraulic model
• flow recirculation
• field velocity

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by CAPES [grant number 001].

Notes on contributors

Iverson Italo Siebert

Iverson Italo Siebert is a civil engineer and did his master in water resources engineering. His main interests focus on fluvial hydraulics, PIV and hydrology.

Michael Mannich

Michael Mannich is Adjunct Professor at the Environmental Engineering Department of the Federal University of Paraná (UFPR), Brazil. His research activities and interests include experimental fluid mechanics, gas transfer in air-water interface, dispersion and physical limnology.

Tobias Bleninger

Tobias Bleninger is Professor (2011) for Environmental Fluid Mechanics, and Applied Mathematics at the Department of Environmental Engineering of the Federal University of Paraná (UFPR) in Curitiba, Brazil. He is a Civil Engineer (2000) from the Karlsruhe Institute of Technology (KIT), Germany, where he did his Doctor in Environmental Fluid Mechanics (2006) and led the research group of Environmental Fluid Mechanics of the Institute for Hydromechanics (2007–2011). Tobias Bleninger has experience in Hydraulics and Fluid Mechanics, with focus on physical and numerical modelling of Mixing and Transport Processes of Environmental Fluid Systems.