scholarly journals Porous medium on unsteady Helical flows of Generalized Oldroyd-B with two infinite coaxial circular cylinders

2021 ◽  
Author(s):  
Alaa Waleed
Keyword(s):  
Porous Medium ◽  
Porous Media ◽  
Velocity Field ◽  
Fractional Derivative ◽  
Kinematic Viscosity ◽  
Magnetic Parameter ◽  
Velocity Fields ◽  
Circular Cylinders ◽  
Series Form ◽  
Permeability Parameter

This article deals with the influence of porous media on Helical flows of Generalized Oldroyd-B between two infinite coaxial circular cylinders .The fractional derivative are modeled for this problem and studied by using finite Hankel and Laplace transforms .The velocity fields founded by using the fundamentals of the series form  in terms of  Mittag-leffler equation . The research focused on the parameters like (permeability parameter  z ,fractional parameters(𝛼 , 𝛽) , relaxation 𝜆1 , retardation 𝜆2 , kinematic viscosity v , magnetic parameter M and time t) which effected on the velocity field u and w. MATHEMATICA package used to study and analyze the above  variables by drawing many graphs .

scholarly journals Influence of Inclined MHD on Unsteady Flow of Generalized Maxwell Fluid with Fractional Derivative between Two Inclined Coaxial Cylinders through a Porous Medium

2020 ◽  
pp. 1705-1714
Author(s):  
Sundos Bader ◽  
Suad Naji Kadhim ◽  
Ahmed. M. Abdulhadi
Keyword(s):  
Porous Medium ◽  
Velocity Field ◽  
Fractional Derivative ◽  
Maxwell Fluid ◽  
Hankel Transform ◽  
Analytic Solutions ◽  
Circular Cylinders ◽  
Physical Parameters ◽  
The Laplace Transform ◽  
Generalized Maxwell Fluid

"This paper presents a study of inclined magnetic field on the unsteady rotating flow of a generalized Maxwell fluid with fractional derivative between two inclined infinite circular cylinders through a porous medium. The analytic solutions for velocity field and shear stress are derived by using the Laplace transform and finite Hankel transform in terms of the generalized G functions. The effect of the physical parameters of the problem on the velocity field is discussed and illustrated graphically.

scholarly journals Transient Fluid Motions in Saturated Porous Media

1957 ◽  
Vol 10 (1) ◽  
pp. 43 ◽  
Author(s):  
JR Philip
Keyword(s):  
Porous Medium ◽  
Porous Media ◽  
Heat Conduction ◽  
Exact Solutions ◽  
Kinematic Viscosity ◽  
Saturated Porous Medium ◽  
Steady Motion ◽  
Potential Gradient ◽  
Saturated Porous Media ◽  
Approximate Analysis

The transition from rest to steady motion on the sudden application of a potential gradient to the fluid contained in a saturated porous medium is investigated. An approximate analysis gives the result that the time of the effective establishment of the steady motion is proportional to the permeability and inversely proportional to the kinematic viscosity. Two exact solutions (one of them new) for simple cases suggest that the approximate analysis is remarkably accurate. An analogy between this problem and one in heat conduction makes the relevant results in that field immediately applicable here.

scholarly journals LINEAR AND NONLINEAR INSTABILITY OF FLOW IN CHANNEL OCCUPIED POROUS MEDIA

2017 ◽  
Vol 39 (3) ◽  
pp. 40-46
Author(s):  
A.A. Avramenko ◽  
N.P. Dmitrenko ◽  
Y.Y. Kovetskaya
Keyword(s):  
Porous Medium ◽  
Porous Media ◽  
Kinematic Viscosity ◽  
Hydrodynamic Instability ◽  
Linear Instability ◽  
Nonlinear Instability ◽  
Linear Perturbations ◽  
Linear And Nonlinear

The paper investigates linear and nonlinear hydrodynamic instability of flow in channel ocuped porous medium. The effects of linear instability are considered using the method of linear perturbations. The nonlinear instability of the flow is considered using the renormalized expression for the coefficient of the kinematic viscosity.

Analysis of Darcy Flow in Confined Porous Media Including Wall Effect

2011 ◽  
Author(s):  
Nihad Dukhan
Keyword(s):  
Heat Transfer ◽  
Porous Medium ◽  
Porous Media ◽  
Heat Exchange ◽  
Velocity Field ◽  
Darcy Number ◽  
Momentum Transport ◽  
Mean Velocity ◽  
Viscous Shear ◽  
The Mean

Effective cooling lies at the heart of reactor design and safe operation. Materials for cooling systems include solid porous media (e.g. metal foam). This is due to the large surface area per unit volume and the random internal structure of such porous medium. The former promotes heat exchange rates by providing large surface area, while the latter enhances it by providing vigorous mixing of the working fluid, which gives rise to what is called dispersion (an added mechanism of heat transfer). Hence, momentum transport in porous media is critical for heat transfer analysis, computation and design. Porous media are also used as storage of nuclear waste. In such applications, the porous medium is confined by solid boundaries. These impermeable boundaries give rise to shear stress and boundary layers, which strongly influence the velocity field and the pressure drop inside the porous medium. The velocity field directly influence the heat transfer rate, while the pressure drop determines the required pumping power. The Brinkman-extended Darcy equation describes the momentum transport due to fully developed Newtonian fluid flow in confined porous media. This equation is an extension of the famous Darcy equation, and it contains the viscous shear at the boundaries as well as the viscous shear on the internal surface of the porous medium. The equation is solved analytically inside and outside the boundary layer in a cylindrical porous-media system. As, expected, the volume-averaged velocity decays as the distance from the boundary increases. The mean and maximum velocities are obtained and their behavior is investigated in terms of the Darcy number and the ratio of the effective to the actual fluid viscosity. The friction factor is defined based on the mean velocity and is found to be inversely proportional to the Reynolds number, the Darcy number and the mean velocity. The analytical velocity can be directly substituted in the governing convection heat transfer equation to assess the heat transfer performance of confined cylindrical heat exchange systems.

scholarly journals Magnetohydrodynamic Three Dimensional Flow and Heat Transfer Past a Vertical Porous Plate Through a Porous Medium with Periodic Suction

1970 ◽  
Vol 46 (4) ◽  
pp. 465-474 ◽  
Author(s):  
SS Das ◽  
M Mitra ◽  
PK Mishra
Keyword(s):  
Heat Transfer ◽  
Porous Medium ◽  
Flow Field ◽  
Prandtl Number ◽  
Skin Friction ◽  
Magnetic Parameter ◽  
Three Dimensional ◽  
Three Dimensional Flow ◽  
Suction Parameter ◽  
Permeability Parameter

This paper analyzes the effect of magnetic field and the permeability of the medium on the three dimensional flow of a viscous incompressible electrically conducting fluid through a porous medium bounded by an infinite vertical porous plate in presence of periodic suction and a transverse magnetic field. The governing equations for the velocity and temperature of the flow field are solved employing perturbation technique and the effects of the pertinent parameters such as magnetic parameter (M), suction parameter (α), permeability parameter (Kp), Reynolds number (Re) and Prandtl number (Pr) on the velocity field, temperature field, skin friction and the rate of heat transfer are discussed with the help of figures and tables. It is observed that both magnetic parameter and the permeability parameter have accelerating effect on the velocity of the flow field. The effect of growing Prandtl number/suction parameter/ Reynolds number is to enhance the temperature of the flow field at all points while a growing magnetic parameter has retarding effect on the temperature field. The magnetic parameter increases the x-component of skin friction and reduces the magnitude of z-component of skin friction at the wall while the permeability parameter shows the reverse effect on both the components of skin friction. The rate of heat transfer at the wall grows as we increase the magnetic parameter or suction parameter or Prandtl number in the flow field and the effect reverses with the increase of the permeability parameter. Key words: MHD; Three dimensional flow; Heat transfer; Vertical plate; Porous medium; Periodic suction   DOI: http://dx.doi.org/10.3329/bjsir.v46i4.9593 BJSIR 2011; 46(4): 465-474

Investigation of Interstitial Velocity Field Inside Micro-Porous Media

2010 ◽  
Author(s):  
Debjyoti Sen ◽  
Mona Abdolrazaghi ◽  
David S. Nobes ◽  
Sushanta K. Mitra
Keyword(s):  
Porous Media ◽  
Velocity Field ◽  
Three Dimensional ◽  
Cross Flow ◽  
Flow Cell ◽  
Velocity Fields ◽  
Pore Region ◽  
Flow Recirculation ◽  
Two Component ◽  
Interstitial Velocity

An investigation of interstitial velocity field within a micro porous media is studied using a three component three dimensional (3C3D) μ-PIV system. The porous media is formed by packing of micro glass beads of size 400 μm inside a flow cell. The two component two dimensional (2C2D) velocity fields in micro pore region are obtained near the wall. 3C3D velocity field is obtained by scanning through 100 μm inside the porous media using the scanning μ-PIV system. Cross flow pattern and flow recirculation is observed within the micro pore region.

Motion of circular cylinders during natural convection flow in X-shaped cavity filled with a nanofluid using ISPH method

2021 ◽  
Vol 31 (5) ◽  
pp. 1449-1474 ◽  
Author(s):  
Abdelraheem M. Aly ◽  
Ehab Mahmoud Mohamed
Keyword(s):  
Porous Medium ◽  
Porous Media ◽  
Natural Convection ◽  
Thermal Conditions ◽  
Circular Cylinders ◽  
Convection Flow ◽  
Natural Convection Flow ◽  
Content Type ◽  
Temperature Distributions ◽  
Cold Source

Purpose This study aims to illustrate the impacts of the motion of circular cylinders on the natural convection flow from variable heated partitions inside the X-shaped cavity filled with Al2O3-water nanofluid. A partial layer of a homogeneous/heterogeneous porous medium is located in the top area of the X-shaped cavity. Design/methodology/approach Three different cases of the porous media including homogeneous, horizontal heterogeneous and vertical heterogeneous porous media were considered. Three different thermal conditions of the embedded circular cylinders including hot, cold and adiabatic conditions are investigated. An incompressible scheme of smoothed particle hydrodynamics (ISPH) method is modified to compute the non-linear partial differential equations of the current problem. Two variable lengths of the left and right sides of the X-shaped cavity have a high-temperature Th and a low-temperature Tc, respectively. The other wall parts are adiabatic. The numerical simulations are elucidating the dependence of the heat transfer and fluid flow characteristics on lengths of hot/cold source Lh, porous cases, Darcy parameter, thermal conditions of the embedded circular cylinders and solid volume fraction. Findings Overall, an increment in length of hot/cold source leads to augmentation on the temperature distributions and flow intensity inside the X-shaped cavity. The hot thermal condition of the circular cylinder augments the temperature distributions. The homogeneous porous medium slows down the flow speed in the top porous layer of the X-shaped cavity. The average Nusselt number decreases as Lh increases. Originality/value ISPH method simulated the motion of circular cylinders in the X-shaped cavity. The X-shaped cavity is saturated with a partial layer porous medium. It is found that an increase in hot source length augments the temperature and fluid flow. ISPH method can easily handle the motion of cylinders in the X-shaped cavity. Different thermal conditions of cylinders can change the temperature distributions in X-cavity.

Statistical Analysis of Velocity Fields Obtained From Experimental Study of Micro-Porous Media

2012 ◽  
Author(s):  
Debjyoti Sen ◽  
David S. Nobes ◽  
Sushanta K. Mitra
Keyword(s):  
Experimental Study ◽  
Porous Media ◽  
Statistical Analysis ◽  
Velocity Field ◽  
Velocity Fields ◽  
Field Of View ◽  
Characteristic Velocity ◽  
Micro Scale ◽  
Micro Piv ◽  
Volume Of Interest

An experimental technique based on scanning a thin field of view through a volume of interest and micro-PIV is used to determine velocity field within a micro porous media. Statistical methods are used to investigate the characteristic distributions of velocity for the micro scale flow. The similarity in velocity trends between macro porous media and micro porous media is established. The behavior of these characteristic velocity distributions in a single pore and multipore systems is discussed.

EFFECT OF MAGNETIC FIELD ON PERISTALTIC TRANSPORT OF COUPLE STRESS FLUIDS THROUGH A POROUS MEDIUM

2011 ◽  
Vol 19 (02) ◽  
pp. 251-262 ◽  
Author(s):  
S. K. PANDEY ◽  
M. K. CHAUBE
Keyword(s):  
Magnetic Field ◽  
Porous Medium ◽  
Axial Velocity ◽  
Couple Stress ◽  
Magnetic Parameter ◽  
Amplitude Ratio ◽  
Perturbation Technique ◽  
Mean Velocity ◽  
Stress Parameter ◽  
Permeability Parameter

This paper analyses peristaltic flow of a couple stress fluid in a channel through a porous medium in the presence of an external magnetic field. The flow is induced by sinusoidal traveling waves along the walls of the channel. The nonlinear convective acceleration terms are duly considered and a perturbation technique is used to solve the problem for the case of small amplitude ratio. The effects of couple-stress parameter, magnetic parameter and permeability parameter on mean velocity on the channel walls, mean axial velocity and critical reflux condition are discussed in detail. Computational results show that the mean velocity at the boundary decreases with increasing couple stress parameter and permeability parameter while it increases with magnetic parameter. It is also revealed that mean axial velocity decreases with increasing couple stress parameter and magnetic parameter while it increases with permeability parameter.

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