scholarly journals Velocity Profiles and Turbulent Characteristics in Channel Flow through an Expanded Region.

1997 ◽  
Vol 63 (616) ◽  
pp. 3849-3855
Author(s):  
Masatoshi SANO
Keyword(s):  
Channel Flow ◽  
Velocity Profiles ◽  
Turbulent Characteristics ◽  
Flow Through

Velocity Profiles of Liquid Flow Through Circular Tubes and How They Affect Flow Measurement

1991 ◽  
Vol 113 (3) ◽  
pp. 206-210 ◽  
Author(s):  
D. Yogi Goswami
Keyword(s):  
Transition Region ◽  
Laser Doppler Velocimetry ◽  
Flow Measurement ◽  
Velocity Profiles ◽  
Turbulent Regime ◽  
Flow Meters ◽  
Circular Tubes ◽  
Flow Through ◽  
Hydrogen Bubble Technique

This paper analyzes velocity profiles for flow through circular tubes in laminar, turbulent, and transition region flows and how they affect measurement by flow-meters. Experimental measurements of velocity profiles across the cross-section of straight circular tubes were made using laser doppler velocimetry. In addition, flow visualization was done using the hydrogen bubble technique. Velocity profiles in the laminar and the turbulent flow are quite predictable which allow the determination of meter factors for accurate flow measurement. However, the profiles can not be predicted at all in the transition region. Therefore, for the accuracy of the flowmeter, it must be ensured that the flow is completely in the laminar regime or completely in the turbulent regime. In the laminar flow a bend, even at a large distance, affects the meter factor. The paper also discusses some strategies to restructure the flow to avoid the transition region.

Modeling of the Ionized Fluid Flow through a Cone-Shaped Nanopore

2007 ◽  
Vol 121-123 ◽  
pp. 1089-1092 ◽  
Author(s):  
Jian Zhong Fu ◽  
Xiao Bing Mi ◽  
Yong He ◽  
Zi Chen Chen
Keyword(s):  
Fluid Flow ◽  
Theoretical Analysis ◽  
Cross Section ◽  
Debye Length ◽  
Velocity Profiles ◽  
Gradual Change ◽  
Ion Flow ◽  
Flow Through

Theoretical analysis of the ionized fluid flowing through a cone-shaped nanopore is presented. The internal cross section of the cone-shaped channel is in the range from micro- to nanometer and gradual change from larger to smaller than the Debye length for the ions. The model is developed to predict the ionized fluid flow behaviors in cone-shaped micro/nanochannels. The velocity profiles of ion flow that occur in nanopores are obtained.

A Combined CFD/MRV Study of Flow Through a Pin Bank

2014 ◽  
Author(s):  
Mike Siekman ◽  
David Helmer ◽  
Wontae Hwang ◽  
Gregory Laskowski ◽  
Ek Tsoon Tan ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Velocity Field ◽  
Turbulence Model ◽  
Field Data ◽  
Peak Velocity ◽  
Velocity Profiles ◽  
Mean Velocity ◽  
Magnetic Resonance Velocimetry ◽  
Sst Turbulence Model ◽  
Flow Through

RANS and time averaged URANS simulations of a pin bank are compared quantitatively and qualitatively to full 3D mean velocity field data obtained using magnetic resonance velocimetry (MRV). The ability of the CFD to match MRV velocity profiles through the pin bank is evaluated using the SST turbulence model. Quantitative comparisons of the velocity profiles showed an overprediction of peak velocity by the CFD at the first pin rows, and a smaller oscillatory error that diminishes as it moves through the pins, resulting in better matching towards the exit.

Large-Scale Forcing of a Turbulent Channel Flow Through Spanwise Synthetic Jets

AIAA Journal ◽  
2020 ◽  
Vol 58 (5) ◽  
pp. 2042-2052 ◽  
Author(s):  
M. Cannata ◽  
G. Cafiero ◽  
G. Iuso
Keyword(s):  
Channel Flow ◽  
Large Scale ◽  
Turbulent Channel Flow ◽  
Synthetic Jets ◽  
Flow Through

Predictions of bulk velocity for open channel flow through submerged vegetation

2020 ◽  
Vol 32 (4) ◽  
pp. 795-799
Author(s):  
Wei-jie Wang ◽  
Xiao-yu Cui ◽  
Fei Dong ◽  
Wen-qi Peng ◽  
Zhen Han ◽  
...  
Keyword(s):  
Channel Flow ◽  
Open Channel ◽  
Open Channel Flow ◽  
Bulk Velocity ◽  
Submerged Vegetation ◽  
Flow Through

Particle Image Velocimetry Measurements of Turbulent Jets Issuing From Twin Elliptic Nozzles With Various Orientations

2020 ◽  
Vol 143 (2) ◽  
Author(s):  
Ella Marie Morris ◽  
Neelakash Biswas ◽  
Seyed Sobhan Aleyasin ◽  
Mark Francis Tachie
Keyword(s):  
Particle Image Velocimetry ◽  
Particle Image ◽  
Symmetry Plane ◽  
Velocity Profiles ◽  
Equivalent Diameter ◽  
Linear Contraction ◽  
Turbulent Characteristics ◽  
Image Velocimetry ◽  
Nozzle Orientation ◽  
Minor Plane

Abstract The effects of nozzle orientation on the mixing and turbulent characteristics of elliptical free twin jets were studied experimentally. The experiments were conducted using modified contoured nozzles with a sharp linear contraction. The centers of the nozzle pair had a separation ratio of 5.5. Two nozzle configurations were tested, twin nozzles oriented along the minor plane (Twin_Minor) and twin nozzles oriented along the major plane (Twin_Major) and the results were compared with a single jet. In each case, the Reynolds number based on the maximum jet velocity and the equivalent diameter was 10,000. A planar particle image velocimetry (PIV) system was used to measure the velocity field in the jet symmetry plane. It was observed that the velocity decay rate is not sensitive to nozzle orientation. However, close to the jet exit, the spread rate was highest in the minor plane. In addition, contour plots of swirling strength, Reynolds shear stress and turbulent intensities revealed significant differences between the minor and major planes. Velocity profiles showed little variation close to the jet exit, while further downstream the variations between the velocity profiles were more pronounced between the major and minor planes.

Effect of Tapering on Pulsatile Flow Through a U-Tube Model of the Human Aortic Arch

2010 ◽  
Author(s):  
Masaru Sumida
Keyword(s):  
Velocity Profile ◽  
Pulsatile Flow ◽  
Velocity Profiles ◽  
Cross Sectional Area ◽  
Flow Rate Ratio ◽  
Sectional Area ◽  
Cross Sectional ◽  
Turn Angle ◽  
Flow Through ◽  
The Cross

An experimental investigation of pulsatile flow through a tapered U-tube was performed to study the blood flow in the aorta. The experiments were carried out in a U-tube with a curvature radius ratio of 3.5 and a 50% reduction in the cross-sectional area from the entrance to the exit of the curved section. Velocity measurements were conducted by a laser Doppler velocimetry for a Womersley number of 10, a mean Dean number of 400 and a flow rate ratio of 1. The velocity profiles for pulsatile flow in the tapered U-tube were compared with the corresponding results in a U-tube having a uniform cross-sectional area. The striking effects of the tapering on the flow are exhibited in the axial velocity profiles in the section from the latter half of the bend to the downstream tangent immediately behind the bend exit. A depression in the velocity profile appears at a smaller turn angle Ω in the case of tapering, although the magnitude of the depression relative to the cross-sectional average velocity decreases. The value of β, which indicates the uniformity in the velocity profile over the cross section, decreases with increasing Ω, whereas it rapidly increases immediately behind the bend exit.

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