Stream gauging by combined use of surface PTV and CFD techniques in channel flows

Aydın, İsmail
A video imagery technique for free surface velocity measuring is presented and used to calculate discharge for uniform open channel flows numerically. When the surface velocities are measured and used as boundary conditions on the water surface, velocity field can then be solved numerically to satisfy the surface boundary conditions. This approach can provide a precise tool for velocity field, discharge and boundary shear distribution calculation. PTV or particle tracking velocimetry is implemented over the free surface to provide the boundary condition for numerical solution. Present paper describes the limitations and capabilities of conducting PTV measurements for a variety of flow conditions. Sensitivity of the PTV measurements is investigated for different lighting conditions, time interval between successive frames, location of the tracking particle, size and material of the particle with respect to changing free surface velocity. Finally, the measured surface velocity are compared to the computed ones.


Application of video imagery techniques for low cost measurement of water surface velocity in open channels
GHARAHJEH, Siamak; Aydın, İsmail (2016-10-01)
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 ...
Discharge formula for rectangular sharp-crested weirs
Aydın, İsmail; Altan Sakarya, Ayşe Burcu (2011-04-01)
Sharp-crested rectangular weirs used for discharge measurement in channels and laboratories are experimentally investigated. Height and width of weir plate are the two parameters characterizing the head-discharge relationship. Laboratory experiments are conducted by measuring the discharge and the head over the weir for variable weir heights and widths. Applicability of various formulations for the discharge coefficient are investigated. Experiments indicate that discharge is independent of weir height, whe...
Streamwise oscillations of a cylinder beneath a free surface: Free surface effects on fluid forces
Kocabiyik, Serpil; Bozkaya, Canan (2015-11-01)
A two-dimensional free surface flow past a circular cylinder forced to perform streamwise oscillations in the presence of an oncoming uniform flow is investigated at a Reynolds number of R=200 and fixed displacement amplitude, A=0.13, for the forcing frequency-to-natural shedding frequency ratios, f/f(0) = 1.5, 2.5, 3.5. The present two-fluid model is based on a velocity-pressure formulation of the two-dimensional continuity and unsteady Navier-Stokes equations. The continuity and Navier-Stokes equations ar...
Numerical Simulation of Reciprocating Flow Forced Convection in Two-Dimensional Channels
Sert, Cüneyt (ASME International, 2003-5-20)
<jats:p>Numerical simulations of laminar, forced convection heat transfer for reciprocating, two-dimensional channel flows are performed as a function of the penetration length, Womersley (α) and Prandtl (Pr) numbers. The numerical algorithm is based on a spectral element formulation, which enables high-order spatial resolution with exponential decay of discretization errors, and second-order time-accuracy. Uniform heat flux and constant temperature boundary conditions are imposed on certain regions of the ...
Flow Structure on Nonslender Delta Wing: Reynolds Number Dependence and Flow Control
Zharfa, Mohammadreza; Ozturk, Ilhan; Yavuz, Mehmet Metin (2016-03-01)
The flow structure over a 35 deg swept delta wing is characterized in a low-speed wind tunnel using techniques of laser-illuminated smoke visualization, laser Doppler anemometry, and surface-pressure measurements. The effects of Reynolds numbers and attack angles on the evaluation of flow patterns are addressed within the broad range of Reynolds number 10(4) < Re < 10(5) and attack angle 3 deg < alpha < 10 deg. In addition, the effect of steady blowing through the leading edges of the wing on flow structure...
Citation Formats
S. GHARAHJEH and İ. Aydın, “Stream gauging by combined use of surface PTV and CFD techniques in channel flows,” 2015, vol. 1, Accessed: 00, 2020. [Online]. Available: