scholarly journals KAJIAN NILAI KOEFISIEN HAMBAT PADA SALURAN TERBUKA

2017 ◽  
Author(s):  
cahya sujatmiko
Keyword(s):  
Drag Coefficient ◽  
Channel Flow ◽  
Open Channel ◽  
Open Channel Flow ◽  
Flow Equation ◽  
Scale Model ◽  
Natural Phenomenon ◽  
Back Door ◽  
Drag Factor ◽  
Bar Diameter

Open channel flow is the natural phenomenon that research by hydraulic engineer. Roughness of thechannel is the drag factor of the flow and the value depend on the roughness caracteristics. Chezy coefficient is the coefficient of flow equation determining velocity at the channel. The value of the chezy coefficient is depend of flow caracteristics and roughness of the channel. Research target conducted to learn the value of the chezy coefficient and drag coefficient at the open channel flow with the cylindrical roughness and determine the parameter having an effect on and also relation usher the parameter. The result of cylindrical will be application to the flow with the resistance grow on mangrove. This research used 6 vertical bar model by 6 variation of density to 2 vertical bar diameter. Simulation model the vertical bar conducted by 4 variation of discharge the stream range from 0,00825 until 0,01374 m3/s and 5 variation of stream deepness by turning around back door ( tail gate). Scale model 1 : 10 used to support the measurement correctness beside consideration of equipments limitation. Research data analysis use the way of comparison between theoretical with the research to yield the relation of non dimensionaless. Result of this research indicate that ever greater of density, depth flow and diameter of cylindrical hence yielded chezy coefficient smaller that mean drag flow is greater. Chezy coefficient yielded range 3,82 – 10,579 m1/2/s with the density range 0,498 – 6,883 while drag coefficient value result of average 0,95. Average velocity for cylindrical roughness can be determine with the equation of Chezy

Hydraulics of offset baffle culvert fishways

1988 ◽  
Vol 15 (6) ◽  
pp. 1043-1051 ◽  
Author(s):  
N. Rajaratnam ◽  
C. Katopodis ◽  
S. Lodewyk
Keyword(s):  
Experimental Study ◽  
Velocity Field ◽  
Turbulent Flow ◽  
Key Words ◽  
Channel Flow ◽  
Open Channel ◽  
Open Channel Flow ◽  
Flow Equation

This paper presents the results of an experimental study on the hydraulics of culverts with offset baffles to pass fish. Using analytical considerations and experimental observations, a flow equation has been developed between the discharge, diameter, depth, and slope for a culvert fish way with the standard offset baffle system. The velocity field at the slot has also been evaluated. Some further experiments were performed to assess the effect of baffle spacing and height on the hydraulics of the culvert fishway. Key words: culverts, fishways, baffles, hydraulics, open-channel flow, turbulent flow.

Statistical structure of high-Reynolds-number turbulence close to the free surface of an open-channel flow

2003 ◽  
Vol 474 ◽  
pp. 355-378 ◽  
Author(s):  
ISABELLE CALMET ◽  
JACQUES MAGNAUDET
Keyword(s):  
Reynolds Number ◽  
Channel Flow ◽  
High Reynolds Number ◽  
Open Channel ◽  
Open Channel Flow ◽  
Surface Region ◽  
Scale Model ◽  
Normal Velocity ◽  
Near Surface ◽  
High Reynolds

Statistical characteristics of turbulence in the near-surface region of a steady open- channel flow are examined using new data obtained in a high-Reynolds-number large-eddy simulation using a dynamic subgrid-scale model. These data, which correspond to a Reynolds number Re* = 1280 based on the total depth and shear velocity at the bottom wall, are systematically compared with those found in available direct numerical simulations in which Re* is typically one order of magnitude smaller. Emphasis is put on terms involved in the turbulent kinetic energy budget (dominated by dissipation and turbulent transport), and on the intercomponent transfer process by which energy is exchanged between the normal velocity component and the tangential ones. It is shown that the relative magnitude of the pressure–strain correlations depends directly on the anisotropy of the turbulence near the bottom of the surface-influenced layer, and that this anisotropy is a strongly decreasing function of Re*. This comparison also reveals the Re*-scaling laws of some of the statistical moments in the near-surface region, especially those involving vorticity fluctuations. Velocity variances, length scales and one-dimensional spectra are then compared with predictions of the rapid distortion theory elaborated by Hunt & Graham (1978) to predict the effect of the sudden insertion of a flat surface on a shearless turbulence. A very good agreement is found, both qualitatively and quantitatively, outside the thin viscous sublayer attached to the surface. As the present high-Reynolds-number statistics have been obtained after a significant number of turnover periods, this agreement strongly suggests that the validity of the Hunt & Graham theory is not restricted to short times after surface insertion.

OPEN CHANNEL FLOW MEASUREMENTS USING SANIIRI FLUME IN SCALE MODEL

2019 ◽  
Author(s):  
Rafael Izidio Libarino ◽  
Victor Chagas ◽  
Robson Leal da Silva ◽  
Wagner André dos Santos Conceição ◽  
Artur Domingos
Keyword(s):  
Channel Flow ◽  
Open Channel ◽  
Open Channel Flow ◽  
Scale Model ◽  
Flow Measurements

Hydraulics of culvert fishways II: slotted-weir culvert fishways

1989 ◽  
Vol 16 (3) ◽  
pp. 375-383 ◽  
Author(s):  
N. Rajaratnam ◽  
C. Katopodis ◽  
N. McQuitty
Keyword(s):  
Experimental Study ◽  
Turbulent Flow ◽  
Key Words ◽  
Channel Flow ◽  
Open Channel ◽  
Open Channel Flow ◽  
Flow Equation ◽  
Flow Depth ◽  
General Manner

This paper presents the results of an experimental study on the hydraulics of culvert fishways with a slotted-weir baffle system. Six designs with two baffle heights and three spacings were tested. A flow equation has been developed to predict the flow depth for any given discharge, diameter, and slope. The barrier velocity that would exist at the slot in the baffles has also been predicted in a general manner. This relatively simple slotted-weir baffle system has been found to match the performance of the more complicated but frequently used offset baffle system of similar dimensions. Key words: culverts, fishways, baffles, hydraulics, turbulent flow, open-channel flow.

Drag coefficient of in-line emergent vegetation in open channel flow

2021 ◽  
pp. 1-31
Author(s):  
Antonino D’Ippolito ◽  
Francesco Calomino ◽  
Giancarlo Alfonsi ◽  
Agostino Lauria
Keyword(s):  
Drag Coefficient ◽  
Channel Flow ◽  
Open Channel ◽  
Open Channel Flow ◽  
Emergent Vegetation
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