Effects of throughflow and internal heat generation on the onset of convection in a fluid layer

2000 ◽  
Vol 140 (3-4) ◽  
pp. 207-217 ◽  
Author(s):  
I. S. Shivakumara ◽  
S. P. Suma
1991 ◽  
Vol 113 (1) ◽  
pp. 122-127 ◽  
Author(s):  
N. Rudraiah ◽  
G. N. Sekhar

The effect of a uniform distribution of heat source on the onset of stationary convection in a horizontal Boussinesq magnetic fluid layer bounded by isothermal nonmagnetic boundaries is investigated. Solutions are obtained using a higher order Galerkin expansion technique, considering different isothermal boundary combinations (rigid-rigid, rigid-free, and free-free). It is found that the effect of internal magnetic number, due to a heat source, is to make the system more unstable. The results obtained, in the limiting cases, compare well with the existing literature.


2016 ◽  
Vol 138 (6) ◽  
Author(s):  
A. V. Kuznetsov ◽  
D. A. Nield

In this paper, we investigated the onset of natural convection in a horizontal fluid layer due to nonuniform internal heat generation, which is relevant to a number of geophysical situations. We investigated a number of special cases, which we believe are paradigmatic. Those include linear, quadratic, concentrated, and exponential source strength distributions. Our results show that those situations that lead to a reduction/increase in the size of the region in which the basic temperature gradient is destabilizing lead to an increase/decrease in stability.


2019 ◽  
Vol 8 (1) ◽  
pp. 546-558 ◽  
Author(s):  
Amit Mahajan ◽  
Reena Nandal

Abstract The present work involves the study of penetrative convection in an incompressible fluid-saturated porous media with local thermal non-equilibrium. The onset of convection evaluated linearly and nonlinearly for the system influenced by heat extraction and heat generation. Darcy-Brinkman law is employed to model the momentum equation and four type of internal heat generating function are considered which leads to thermo-convective instability within the fluid layer. Linear analysis carried out by using normal mode technique and nonlinear stability analysis has been done by energy method. Due to heat generation within the fluid layer and heat extraction through boundary, the subcritical instability may exist with higher possibility. Effects of various parameters as: inter-phase heat transfer parameter, Darcy-Brinkman number, porosity-modified conductivity ratio, and heat parameter are explored on Darcy-Rayleigh number by Chebyshev pseudospectral method as numerical form and graphical form.


2002 ◽  
Vol 2002.42 (0) ◽  
pp. 38-39
Author(s):  
Kengo YONEKURA ◽  
Yuji TASAKA ◽  
Yoichi KUDO ◽  
Norihiko TADATA ◽  
Yasushi TAKEDA ◽  
...  

2018 ◽  
Vol 7 (2.15) ◽  
pp. 86
Author(s):  
Nurul Hafizah Zainal Abidin ◽  
Nor Fadzillah Mohd Mokhtar ◽  
Nur Zarifah Abdul Hamid ◽  
Zanariah Abdul Majid

The effects of temperature dependent viscosity and internal heat generation on the onset of steady Bénard-Marangoni convection in a horizontal binary fluid layer heated from below is investigated theoretically. The upper free surface is assumed to be deformable and the lower boundary is considered to be rigid and perfectly insulated to temperature perturbations. The asymptotic solution of the long wavelength is obtained using regular perturbation method with wave number as a perturbation parameter. It is found that the surface deformation of a binary fluid layer enhances the onset of thermocapillary convection while increasing the value of internal heat generation and temperature dependent viscosity will destabilize the binary fluid layer system. 


Fluids ◽  
2019 ◽  
Vol 4 (2) ◽  
pp. 75 ◽  
Author(s):  
Leiv Storesletten ◽  
D. Andrew S. Rees

The onset of convection in an inclined porous layer which is heated internally by a uniform distribution of heat sources is considered. We investigate the combined effects of inclination, anisotropy and internal heat generation on the linear instability of the basic parallel flow. When the Rayleigh number is sufficiently large, instability occurs and a convective motion is set up. It turns out that the preferred motion at convection onset depends quite strongly on the anisotropy ratio, ξ , and the inclination angle. When ξ < 1 the preferred motion is in the form of longitudinal rolls for all inclinations. When ξ > 1 transverse rolls are preferred for small inclinations but, at high inclinations, longitudinal rolls are preferred. At intermediate inclinations the preferred roll orientation varies smoothly between these two extremes.


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