Experimental Study on Near-bed Flow Turbulence of Sinuous Channel with Downward Seepage

Author(s):  
Jyotismita Taye ◽  
Bimlesh Kumar
2015 ◽  
Vol 137 (3) ◽  
Author(s):  
Seyed Sobhan Aleyasin ◽  
Nima Fathi ◽  
Peter Vorobieff

Understanding the estuarine turbulent flow from dams, channels, and pipes, as well as the river flow are very important due to the potential to cause damage to the bed of the river or channel and cause scouring of structures such as the saddles of bridges, because of the huge amount of the kinetic energy carried by the flow. One of the most efficient yet simple ways to dissipate this energy is to install a stilling basin at the discharge point to calm the flow. Turbulence data were recorded using acoustic Doppler velocimetry (ADV) for type VI2 of stilling basins for pipe outlets. During the study, various splitters and a cellular baffle were placed in the stilling basin, and the baffle locations were changed to assess the effect on the energy dissipation. Velocity at several locations in the basin was measured for different Froude numbers to investigate the effect of flow rate. Based on the findings of the experiments, several suggestions regarding the efficiency and geometry of stilling basins were made.


2018 ◽  
Vol 45 (2) ◽  
pp. 135-151 ◽  
Author(s):  
Anurag Sharma ◽  
Bimlesh Kumar

Present work evaluates the double averaged turbulence characteristics of the sand bed channel subjected to the downward seepage through permeable bed. Measures of turbulent statistics are observed to increase with the application of downward seepage. The form induced stress in near bed has a reducing effect with no seepage and an increasing effect with seepage. The seepage increases the turbulent kinetic energy and turbulent intensities causing the bed particles to move rapidly. The quadrant analysis suggests that at near bed, the sweep events in flows with seepage are the main bursting events towards the Reynolds stress production, while ejection and sweep events in no seepage flow have almost equal contribution. The increase in sediment transport with seepage is caused by an increase in flow turbulence production and an associated decrease in turbulent kinetic energy dissipation and turbulent diffusion.


2012 ◽  
Vol 28 ◽  
pp. 772-775 ◽  
Author(s):  
Zhang Xiufang ◽  
Wang Pingyi ◽  
Yang Chengyu

2018 ◽  
Vol 40 ◽  
pp. 155
Author(s):  
Adrián Roberto Wittwer ◽  
Rodrigo Dorado ◽  
Acir Loredo-Souza ◽  
Arthur Bones ◽  
Bruno Capeller ◽  
...  

An experimental study of the turbulent wake of a wind turbine model was realized at the “Joaquim Blessmann” wind tunnel of the UFRGS. The turbine model was developed at the Universidade de Caxias do Sul and it represents a three blade turbine characterized by a NACA 4412 aerodynamic profile. Measurements of the velocity fluctuations were realized by hot wire anemometry. Complexity of the turbulent flow is evaluated by mean and fluctuating velocity profiles. The influence of the incident flow turbulence and the flow reconstructing process are analyzed by the measurement results.


Author(s):  
Norio Baba ◽  
Norihiko Ichise ◽  
Syunya Watanabe

The tilted beam illumination method is used to improve the resolution comparing with the axial illumination mode. Using this advantage, a restoration method of several tilted beam images covering the full azimuthal range was proposed by Saxton, and experimentally examined. To make this technique more reliable it seems that some practical problems still remain. In this report the restoration was attempted and the problems were considered. In our study, four problems were pointed out for the experiment of the restoration. (1) Accurate beam tilt adjustment to fit the incident beam to the coma-free axis for the symmetrical beam tilting over the full azimuthal range. (2) Accurate measurements of the optical parameters which are necessary to design the restoration filter. Even if the spherical aberration coefficient Cs is known with accuracy and the axial astigmatism is sufficiently compensated, at least the defocus value must be measured. (3) Accurate alignment of the tilt-azimuth series images.


1962 ◽  
Vol 5 (4) ◽  
pp. 387-394 ◽  
Author(s):  
Bruce Quarrington ◽  
Jerome Conway ◽  
Nathan Siegel
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