Application of video imagery techniques for low cost measurement of water surface velocity in open channels


GHARAHJEH S., AYDIN İ.

FLOW MEASUREMENT AND INSTRUMENTATION, vol.51, pp.79-94, 2016 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 51
  • Publication Date: 2016
  • Doi Number: 10.1016/j.flowmeasinst.2016.09.001
  • Title of Journal : FLOW MEASUREMENT AND INSTRUMENTATION
  • Page Numbers: pp.79-94
  • Keywords: Open channel flow, Free surface velocity, Surface PIV, PTV, LSPTV, Discharge measurement, CROSS-CORRELATION, PIV-MEASUREMENTS, PARTICLE, IMPROVEMENT, LIMITATION, MODEL

Abstract

Developments in digital video recording technology make the video imagery tools more popular for velocity measurement in water flows. This has especially been of large interest due to its inherent advantage of non-contact nature which is quite handy in extreme flow conditions. Particle Image Velocimetry (PIV), Particle Tracking Velocimetry (PTV) and Large Scale Particle Tracking Velocimetry (LSPTV) are applied to free surface channel flow for water surface velocity measurement. Experiments are conducted to measure either a single point velocity applying PTV or velocity profiles across the channel width applying PIV on the water surface in a rectang typical velocities of nearly 1 andular tilting flume for various flow conditions. Technical issues regarding tracer particle size and type, travel distance, lighting, recording speed, camera position, image distortion and state of flow are discussed. Measured data is compared to computational results obtained from a numerical model involving a non-linear turbulence model capable of predicting turbulence driven secondary flows. Confirmation of reasonable match between computational and experimental results whereby applying mutual collaboration of them for discharge measurement has been attested. In addition to discharge, boundary roughness has also been predicted as an outcome of the numerical solution. (C) 2016 Elsevier Ltd. All rights reserved.