scholarly journals Flow structure from a horizontal cylinder coincident with a free surface in shallow water flow

2012 ◽  
Vol 16 (1) ◽  
pp. 93-107 ◽  
Author(s):  
Ali Kahraman ◽  
Muammer Özgören ◽  
Beşir Şahin
Keyword(s):  
Free Surface ◽  
Shallow Water ◽  
Water Flow ◽  
Vortex Formation ◽  
Flow Characteristics ◽  
Lower Surface ◽  
Horizontal Cylinder ◽  
Bottom Surface ◽  
Shallow Water Flow ◽  
Cylinder Diameter

Vortex formation from a horizontal cylinder coincident with a free surface of a shallow water flow having a depth of 25.4 [mm] was experimentally investigated using the PIV technique. Instantaneous and time-averaged flow patterns in the wake region of the cylinder were examined for three different cylinder diameter values under the fully developed turbulent boundary layer condition. Reynolds numbers were in the range of 1124? Re? 3374 and Froude numbers were in the range of 0.41 ? Fr ? 0.71 based on the cylinder diameter. It was found that a jet-like flow giving rise to increasing the flow entrainment between the core and wake regions depending on the cylinder diameter was formed between the lower surface of the cylinder and bottom surface of the channel. Vorticity intensity, Reynolds stress correlations and the primary recirculating bubble lengths were grown to higher values with increasing the cylinder diameter. On the other hand, in the case of the lowest level of the jet-like flow emanating from the beneath of the smallest cylinder, the variation of flow characteristics were attenuated significantly in a shorter distance. The variation of the reattachment location of the separated flow to the free-surface is a strong function of the cylinder diameter and the Froude number.

Control of Vortex Shedding of Circular Cylinder in Shallow Water Flow Using an Attached Splitter Plate

2008 ◽  
Vol 130 (4) ◽  
Author(s):  
Huseyin Akilli ◽  
Cuma Karakus ◽  
Atakan Akar ◽  
Besir Sahin ◽  
N. Filiz Tumen
Keyword(s):  
Circular Cylinder ◽  
Shallow Water ◽  
Water Flow ◽  
Vortex Shedding ◽  
Flow Characteristics ◽  
Splitter Plate ◽  
Wake Flow ◽  
Flow Data ◽  
Shallow Water Flow ◽  
Plate Length

In the present work, passive control of vortex shedding behind a circular cylinder by splitter plates of various lengths attached on the cylinder base is experimentally investigated in shallow water flow. Detailed measurements of instantaneous and time-averaged flow data of wake flow region at a Reynolds number of Re=6300 were obtained by particle image velocimetry technique. The length of the splitter plate was varied from L∕D=0.2 to L∕D=2.4 in order to see the effect of the splitter plate length on the flow characteristics. Instantaneous and time-averaged flow data clearly indicate that the length of the splitter plate has a substantial effect on the flow characteristics. The flow characteristics in the wake region of the circular cylinder sharply change up to the splitter plate length of L∕D=1.0. Above this plate length, small changes occur in the flow characteristics.

Intensification of Open Gutters Operation

2020 ◽  
pp. 66-70
Keyword(s):  
Water Flow ◽  
Vortex Formation ◽  
Hydraulic Testing ◽  
Polymer Materials ◽  
Bottom Surface ◽  
Artificial Roughness ◽  
Transport Capacity ◽  
Corrugated Surfaces ◽  
Inner Surface ◽  
Dispersed Inclusions

The intensification of the work of open gutter by applying textured shells to their bottom surface, forming an artificial roughness, is considered. It is shown that the presence of corrugated surfaces contributes to vortex formation during water flow and improves the separation and transportation of mineral impurities previously dropped into the bottom of the gutters. The implementation of operations to improve the structure of the gutters is possible during the repair and restoration works with the use of modern polymer materials. The design of a small-sized hydraulic stand, which makes it possible to study the transport capacity of flows containing solid inclusions, is presented. The method of research is hydraulic testing, accompanied by the use of chiaroscuro effect, as well as photo and film equipment. The optimal structure of the inner surface of the gutters and pipes providing vortex formation, which will improve the ability of the flow to carry out and transport foreign dispersed inclusions (sand) of different granulometric compositions, is determined.

Dealing with shallow-water flow in the deepwater Gulf of Mexico

2002 ◽  
Vol 21 (7) ◽  
pp. 660-668 ◽  
Author(s):  
R. M. Ostermeier ◽  
J. H. Pelletier ◽  
C. D. Winker ◽  
J. W. Nicholson ◽  
F. H. Rambow ◽  
...  
Keyword(s):  
Gulf Of Mexico ◽  
Shallow Water ◽  
Water Flow ◽  
Shallow Water Flow
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