Turbulent pipe flow velocity profile model for drag-reducing fluids

AIChE Journal ◽  
1985 ◽  
Vol 31 (3) ◽  
pp. 520-522 ◽  
Author(s):  
A. V. Shenoy ◽  
M. M. Talathi
Keyword(s):  
Velocity Profile ◽  
Flow Velocity ◽  
Pipe Flow ◽  
Turbulent Pipe Flow ◽  
Profile Model ◽  
Flow Velocity Profile

Investigation of the influence of the flow structure on the accuracy of flow measurement before a hydrometric structure in an open channel

2020 ◽  
pp. 41-44
Author(s):  
Anatoly Kusher
Keyword(s):  
Velocity Profile ◽  
Flow Velocity ◽  
Water Flow ◽  
Flow Measurement ◽  
Water Discharge ◽  
Critical Depth ◽  
Flow Measurements ◽  
Study Results ◽  
Flow Velocity Profile ◽  
Upstream Flow

The reliability of water flow measurement in irrigational canals depends on the measurement method and design features of the flow-measuring structure and the upstream flow velocity profile. The flow velocity profile is a function of the channel geometry and wall roughness. The article presents the study results of the influence of the upstream flow velocity profile on the discharge measurement accuracy. For this, the physical and numerical modeling of two structures was carried out: a critical depth flume and a hydrometric overfall in a rectangular channel. According to the data of numerical simulation of the critical depth flume with a uniform and parabolic (1/7) velocity profile in the upstream channel, the values of water discharge differ very little from the experimental values in the laboratory model with a similar geometry (δ < 2 %). In contrast to the critical depth flume, a change in the velocity profile only due to an increase in the height of the bottom roughness by 3 mm causes a decrease of the overfall discharge coefficient by 4…5 %. According to the results of the numerical and physical modeling, it was found that an increase of backwater by hydrometric structure reduces the influence of the upstream flow velocity profile and increases the reliability of water flow measurements.

The Influence of the Exit Velocity Profile on the Noise of a Jet

1954 ◽  
Vol 4 (4) ◽  
pp. 341-360 ◽  
Author(s):  
Alan Powell
Keyword(s):  
Velocity Profile ◽  
Noise Level ◽  
Turbulent Pipe Flow ◽  
Aerodynamic Noise ◽  
Noise Levels ◽  
Flow Forming ◽  
Flow Velocity Profile ◽  
Jet Velocity ◽  
Initial Turbulence ◽  
Moving Fluid

SummaryThe noise levels of a jet issuing from a long pipe are compared with those of a jet having a square velocity profile at the exit. A subsonic noise reduction of between 2 and 5 decibels for various conditions is found for the case of the flow emerging with an approximately “turbulent pipe-flow” velocity profile for the same maximum jet velocity, but this is at the expense of a loss in thrust of a quarter. On comparison with a jet of smaller diameter which has an equal thrust for the same maximum jet velocity, it is found that the changes in noise level are rather smaller. For jets of equal diameters, the effects on the subsonic aerodynamic noise generated of a reduction of velocity gradient near the boundary are more than offset by the increased velocities necessary near the centre of the jet to obtain equal thrust. It is concluded that if the effect of differences in initial turbulence can be neglected the use of an auxiliary flow forming a comparatively thin sheath of slower moving fluid at the exit is not likely to result in large decreases in the subsonic noise level, and that a general reduction in jet velocity is more effective.Above the critical pressure larger reductions of up to 10 decibels are found. These are consistent with a delay of the onset of the self-maintained shock-produced noise.

scholarly journals Flow Velocity Profile of Micro Counter-Current Flows

2007 ◽  
Vol 23 (2) ◽  
pp. 131-133 ◽  
Author(s):  
Arata AOTA ◽  
Akihide HIBARA ◽  
Kyosuke SHINOHARA ◽  
Yasuhiko SUGII ◽  
Koji OKAMOTO ◽  
...  
Keyword(s):  
Velocity Profile ◽  
Flow Velocity ◽  
Flow Velocity Profile ◽  
Current Flows ◽  
Counter Current
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