Effect of aspect ratio on flow through and around a porous disk

2021 ◽  
Vol 6 (7) ◽  
Author(s):  
Tingting Tang ◽  
Jin Xie ◽  
Shimin Yu ◽  
Jianhui Li ◽  
Peng Yu
Keyword(s):  
Aspect Ratio ◽  
Porous Disk ◽  
Flow Through

scholarly journals Flow through a helical pipe with rectangular cross-section

1970 ◽  
Vol 4 (2) ◽  
pp. 99-110
Author(s):  
Md Mahmud Alam ◽  
Delowara Begum ◽  
K Yamamoto
Keyword(s):  
Aspect Ratio ◽  
Iterative Method ◽  
Cross Section ◽  
Rectangular Cross Section ◽  
Main Tool ◽  
Numerical Approach ◽  
Dean Number ◽  
Helical Pipe ◽  
Flow Through ◽  
Marine Engineering

The effects of torsion, aspect ratio and curvature on the flow in a helical pipe of rectangular cross- section are studied by introducing a non-orthogonal helical coordinate system. Spectral method is applied as main tool for numerical approach where Chebyshev polynomial is used. The numerical calculations are obtained by the iterative method. The calculations are carried out for 0≤ δ ≤0.02, 1≤ λ ≤ 2.85, 1≤ γ ≤2.4, at Dn = 50 & 100 respectively, where d is the non-dimensional curvature, l the torsion parameter, g the aspect ratio and  Dn the pressure driven parameter (Dean number).DOI: http://dx.doi.org/10.3329/jname.v4i2.991 Journal of Naval Architecture and Marine Engineering Vol.4(2) 2007 p.99-110

Slip Flow in Eccentric Annuli

2017 ◽  
Vol 139 (4) ◽  
Author(s):  
R. S. Alassar
Keyword(s):  
Aspect Ratio ◽  
Average Velocity ◽  
Slip Flow ◽  
Small Aspect Ratio ◽  
Channel Geometry ◽  
Bipolar Coordinates ◽  
Cylindrical Annulus ◽  
Velocity Flow ◽  
Flow Through ◽  
Eccentric Annuli

A solution of the problem of Poiseuille slip flow through an eccentric cylindrical annulus is obtained in bipolar coordinates. The solution is in excellent agreement with the two published limiting cases of slip flow through concentric annuli and no-slip flow through eccentric annuli. It is shown that for a fixed aspect ratio, fully eccentric channels sustain the maximum average velocity (flow rate) under the same pressure gradient and slip conditions. For a given channel geometry, the average velocity varies linearly with Knudsen number except for small aspect ratio. It is also shown that the extrema of the friction factor Reynolds number product is determined by how this product is defined or scaled.

Fluid Mechanics of Flow Through Rectangular Hydrophobic Microchannels

2011 ◽  
Author(s):  
Navid Kashaninejad ◽  
Weng Kong Chan ◽  
Nam-Trung Nguyen
Keyword(s):  
Aspect Ratio ◽  
Rectangular Cross Section ◽  
Expansion Method ◽  
Channel Height ◽  
Parallel Plates ◽  
Laminar Regime ◽  
Dimensional Solution ◽  
Eigenfunction Expansion Method ◽  
Flow Through ◽  
Liquid Flows

In this study, the effect of two important parameters have been evaluated for pressure driven liquid flows in microchannel in laminar regime by analytical modeling, followed by experimental measurement. These parameters are wettability conditions of microchannel surfaces and aspect ratio of rectangular microchannels. For small values of aspect ratio, the channel was considered to have a rectangular cross-section, instead of being two parallel plates. Novel expressions for these kinds of channels were derived using eigenfunction expansion method. The obtained two-dimensional solutions based on dual finite series were then extended to the case of a constant slip velocity at the bottom wall. In addition, for large values of aspect ratio, a general equation was obtained which is capable of accounting for different values of slip lengths for both upper and lower channel walls. Firstly, it was found out that for low aspect ratio microchannels, the results obtained by analytical rectangular 2-D model agree well with the experimental measurements as compared to one dimensional solution. For high aspect ratio microchannels, both models predict the same trend. This finding indicates that using the conventional 1-D solution may not be accurate for the channels where the width is of the same order as the height. Secondly, experimental results showed that up to 2.5% and 16% drag reduction can be achieved for 1000 and 250 micron channel height, respectively. It can be concluded that increasing the surface wettability can reduce the pressure drop in laminar regime and the effect is more pronounced by decreasing the channel height.

Flow through curved rectangular channels of large aspect ratio

AIChE Journal ◽  
1995 ◽  
Vol 41 (5) ◽  
pp. 1061-1070 ◽  
Author(s):  
Matthew J. Targett ◽  
William B. Retallick ◽  
Stuart W. Churchill
Keyword(s):  
Aspect Ratio ◽  
Large Aspect Ratio ◽  
Rectangular Channels ◽  
Flow Through

scholarly journals Effect of Lateral Walls on Peristaltic Flow through an Asymmetric Rectangular Duct

2011 ◽  
Vol 8 (3-4) ◽  
pp. 295-308 ◽  
Author(s):  
Kh. S. Mekheimer ◽  
S. Z.-A. Husseny ◽  
A. I. Abd el Lateef
Keyword(s):  
Reynolds Number ◽  
Aspect Ratio ◽  
Viscous Fluid ◽  
Wave Train ◽  
Peristaltic Flow ◽  
Frame Of Reference ◽  
Rectangular Duct ◽  
Long Wavelength ◽  
Flow Through ◽  
Lateral Walls

Peristaltic transport of an incompressible viscous fluid due to an asymmetric waves propagating on the horizontal sidewalls of a rectangular duct is studied under long-wavelength and low-Reynolds number assumptions. The peristaltic wave train on the walls have different amplitudes and phase. The flow is investigated in a wave frame of reference moving with velocity of the wave. The effect of aspect ratio, phase difference, varying channel width and wave amplitudes on the pumping characteristics and trapping phenomena are discussed in detail. The results are compared to with those corresponding to Poiseuille flow.

scholarly journals Variation of Pressure Drop along the Straight and Bifurcated Channel: Experiment and Simulation

2019 ◽  
Vol 8 (12) ◽  
pp. 2728-2731
Keyword(s):  
Pressure Drop ◽  
Laminar Flow ◽  
Aspect Ratio ◽  
Computational Model ◽  
Flow Rate ◽  
Normal Water ◽  
Flow Through ◽  
Experiment And Simulation

This paper derives an experimental and simulated investigation carried to analyze the performance of channel for calculating the pressure drop in laminar flow through rectangular shaped (straight and branched) microchannels. The microchannels taken ranged in variable aspect ratio from 0.75 to 1. Every check piece was made from copper and contained only one channel along a direction. The experiments were conducted with normal water, with Reynolds range starting from some 720 to 3500. Predictions obtained supported that with the variation in the aspect ratio the properties of the fluid also change. It is observed that the pressure drop changes with the change in the aspect ratio and flow rate and found that there is a correlation between the experimental and computational model results.

Sign in / Sign up

Export Citation Format

Share Document