819 Fluid Flow through Biplane Grid and the Resistance Coefficient : Estimate of drag coefficient and influence of Reynolds number

2007 ◽  
Vol 2007 (0) ◽  
pp. 303-304
Author(s):  
Hidemi YAMADA ◽  
Seigo OKA
1945 ◽  
Vol 153 (1) ◽  
pp. 154-168 ◽  
Author(s):  
H. E. Rose

The resistance coefficient–Reynolds number relationship for a bed of spherical particles, closely graded about a mean size, is considered and it is shown that this relationship correlates with that for a bed of non-spherical particles, provided a suitable allowance for particle shape is made. It is shown that for very large or very small values of the Reynolds number the co-ordinates of the resistance coefficient–Reynolds number curve fall closely about a mean line but for the transition-range the points suffer considerable scatter—probably due to the indeterminate nature of the flow in the pore channels for this range of the Reynolds number. Curves are given showing the frequency of occurrence of variations in the resistance coefficient, and an example of the practical application of these curves to a design problem is fully worked out. Curves relating the resistance coefficient to the Reynolds number for beds of particles of various degrees of angularity are put forward tentatively, these relationships being, as yet, not completely established.


1999 ◽  
Author(s):  
Mario F. Letelier ◽  
César E. Rosas

Abstract A theoretical study of the fully developed fluid flow through a confined porous medium is presented. The fluid is described by the Bingham plastic model for small values of the yield number. The analysis allows for many admissible shapes of the wall contour. The velocity field is computed for several combination of relevant parameters, i.e., the yield number, Darcy resistance coefficient and the boundary perturbation parameter. The wall effect is especially highlighted and the characteristics of the central plug region as well. Plots of isovel curves and velocity profiles are included for a variety of flow and geometry parameters.


Author(s):  
Waqas Waheed ◽  
Anas Alazzam ◽  
Ashraf N. Al Khateeb ◽  
Eiyad Abu Nada

In this paper, a two-dimensional Dissipative Particle Dynamics (DPD) technique to simulate the poiseuille flow in a microchannel is developed using an in-house code. The calculated Reynolds number is reduced via adjusting the DPD parameters. The obtained velocity profile is compared with the analytical results and a good agreement is found. The drag force and the drag coefficient on a stationary cylinder exerted by the fluid particles are obtained using the developed DPD code. The calculated drag coefficient exhibits a close match with already published data in the literature.


2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Ilyas Khan ◽  
Abid A. Memon ◽  
M. Asif Memon ◽  
Kaleemullah Bhatti ◽  
Gul M. Shaikh ◽  
...  

This article aims to study Newtonian fluid flow modeling and simulation through a rectangular channel embedded in a semicircular cylinder with the range of Reynolds number from 100 to 1500. The fluid is considered as laminar and Newtonian, and the problem is time independent. A numerical procedure of finite element’s least Square technique is implemented through COMSOL multiphysics 5.4. The problem is validated through asymptotic solution governed through the screen boundary condition. The vortex length of the recirculating region formed at the back of the cylinder and orientation of velocity field and pressure will be discussed by three horizontal and four vertical lines along the recirculating region in terms of Reynolds number. It was found that the two vortices of unequal size have appeared and the lengths of these vortices are increased with the increase Reynolds number. Also, the empirical equations through the linear regression procedure were determined for those vortices. The orientation of the velocity magnitude as well as pressure along the lines passing through the center of upper and lower vortices are the same.


Author(s):  
Ahmed Yousif

A 2-D computational analysis is carried out to calculate heat transfer and friction factor for laminar flow through a rectangular duct with using fan–shape ribs as a turbulator. The types of rib shapes are imported on the heat transfer rate and fluid flow in heat exchangers. The present study makes use of fan-shaped ribs with two arrangements. The first arrangement was downstream fan–shape ribs (case 1) and upstream fan–shape ribs (case 2) is investigated. A commercial finite volume package ANSYS FLUENT 16.1 is used for solving the meshing process with continuity, momentum, and energy equations respectively to investigate fluid flow and heat transfer across the ribs surface. The Reynolds number (Re) range of (400 – 2250) with different relative roughness pitch (p/H= 0.17, 0.22, 0.27 and 0.32) at constant rib high (e/H). The results show that the heat transfers and friction increase with using ribs also, the results show that heat transfer Directly proportional to pitch ratio and Reynolds number. The Nusselt number enhancement by (12% -29%).    


2020 ◽  
Vol 24 (2 Part B) ◽  
pp. 1045-1054 ◽  
Author(s):  
Mehdi Ahmadi ◽  
Farsani Khosravi

In this paper, the numerical solution of non-Newtonian two-phase fluid-flow through a channel with a cavity was studied. Carreau-Yasuda non-Newtonian model which represents well the dependence of stress on shear rate was used and the effect of n index of the model and the effect of input Reynolds on the attribution of flow were considered. Governing equations were discretized using the finite volume method on staggered grid and the form of allocating flow parameters on staggered grid is based on marker and cell method. The QUICK scheme is employed for the convection terms in the momentum equations, also the convection term is discretized by using the hybrid upwind-central scheme. In order to increase the accuracy of making discrete, second order Van Leer accuracy method was used. For mixed solution of velocity-pressure field SIMPLEC algorithm was used and for pressure correction equation iteratively line-by-line TDMA solution procedure and the strongly implicit procedure was used. As the results show, by increasing Reynolds number, the time of sweeping the non-Newtonian fluid inside the cavity decreases, the velocity of Newtonian fluid increases and the pressure decreases. In the second section, by increasing n index, the velocity increases and the volume fraction of non-Newtonian fluid after cavity increases and by increasing velocity, the pressure decreases. Also changes in the velocity, pressure and volume fraction of fluids inside the channel and cavity are more sensible to changing the Reynolds number instead of changing n index.


1994 ◽  
Vol 60 (569) ◽  
pp. 40-47
Author(s):  
Hideo Osaka ◽  
Koji Utsunomiya ◽  
Hiroshi Edamura ◽  
Hidemi Yamada

1987 ◽  
Vol 30 (270) ◽  
pp. 1928-1934
Author(s):  
Toyofumi KATOH ◽  
Masanori KYO ◽  
Shin KAWAMATA ◽  
Nobunori OHSHIMA

1949 ◽  
Vol 160 (1) ◽  
pp. 493-511 ◽  
Author(s):  
H. E. Rose ◽  
A. M. A. Rizk

In this paper the results of previous researches are extended and equations developed by means of which the resistance to fluid flow offered by a bed of spherical or non-spherical material may be computed with reasonable accuracy. The equations cover a range of porosity of the bed from 30 per cent to 90 per cent and practically the whole of the technically important range of Reynolds number, while particle shapes ranging from spheres to hollow cylinders, shell insulators and wire nails are covered. A new curve for wall-effect, depending upon Reynolds number, is also included. It is believed that the present work is of more general application than any which has previously been suggested.


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