Effect of Thermal Modulation on the Onset of Convection in a Porous Medium Layer Saturated by a Nanofluid

2013 ◽  
Vol 98 (1) ◽  
pp. 59-79 ◽  
Author(s):  
J. C. Umavathi
Keyword(s):  
Porous Medium ◽  
Thermal Modulation ◽  
Onset Of Convection ◽  
Medium Layer

Effects of rotation and varying gravity on the onset of convection in a porous medium layer: a numerical study

2020 ◽  
Vol 17 (6) ◽  
pp. 785-793
Author(s):  
Dhananjay Yadav
Keyword(s):  
Porous Medium ◽  
Numerical Study ◽  
Rotation Parameter ◽  
Gravity Variation ◽  
Uniform Rotation ◽  
Onset Of Convection ◽  
Content Type ◽  
Medium Layer ◽  
Variation Parameter ◽  
Effects Of Rotation

Purpose The purpose of this study is to examine the influence of rotation and varying gravitational strength on the onset of thermal convection in a porous medium layer numerically. The porous layer is acted to uniform rotation and inconsistent downward gravitational field which changing with depth from the layer. The authors presented three categories of gravitational strength deviancy, namely, linear, parabolic and exponential. Design/methodology/approach The higher-terms Galerkin weighted residual procedure is applied to get the eigenvalue of the problem. Findings The results illustrate that both rotation parameter and gravity variation parameter suspend the arrival of convection. The measurement of the convection cells decreases on enhancing the rotation parameter and gravity variation parameter. Originality/value It is also found that the scheme is more stable for category exponential, whereas it is more unstable for category parabolic.

Onset of Convection in a Porous Medium Layer Saturated With an Oldroyd-B Nanofluid

2016 ◽  
Vol 139 (1) ◽  
Author(s):  
J. C. Umavathi ◽  
J. Prathap Kumar
Keyword(s):  
Porous Medium ◽  
Volume Fraction ◽  
Momentum Equation ◽  
Nanoparticle Volume Fraction ◽  
Oscillatory Convection ◽  
Nonlinear Stability Analysis ◽  
Onset Of Convection ◽  
Fourier Series Method ◽  
Medium Layer ◽  
Linear And Nonlinear

A linear and nonlinear stability analysis of a viscoelastic fluid in a porous medium layer saturated by a nanofluid with thermal conductivity and viscosity dependent on the nanoparticle volume fraction is studied. To simulate the momentum equation in porous media, a modified Darcy model has been used. To describe the rheological behavior of viscoelastic nanofluids, an Oldroyd-B type constitutive equation has been used. The onset criterion for stationary and oscillatory convection is derived analytically. The nonlinear theory based on the truncated representation of Fourier series method is used to find the transient heat and mass transfer.

Effects of a magnetic field on the onset of convection in a porous medium

1995 ◽  
Vol 30 (4) ◽  
pp. 259-267 ◽  
Author(s):  
S. Alchaar ◽  
P. Vasseur ◽  
E. Bilgen
Keyword(s):  
Magnetic Field ◽  
Porous Medium ◽  
Onset Of Convection
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