Abstract
The effect of thermal/gravity modulation on the onset of convection in a Maxwell fluid saturated porous layer is investigated by a linear stability analysis. Modified Darcy–Maxwell model is used to describe the fluid motion. The regular perturbation method based on the small amplitude of modulation is employed to compute the critical Rayleigh number and the corresponding wavenumber. The stability of the system characterized by a correction Rayleigh number is calculated as a function of the viscoelastic parameter, Darcy–Prandtl number, normalized porosity, and the frequency of modulation. It is found that the low frequency symmetric thermal modulation is destabilizing while moderate and high frequency symmetric modulation is always stabilizing. The asymmetric modulation and lower wall temperature modulations are, in general, stabilizing while the system becomes unstable for large values of Darcy–Prandtl number and for small frequencies. It is shown that in general the gravity modulation produces a stabilizing effect on the onset of convection for moderate and high frequency. The small frequency gravity modulation is found to have destabilizing effect on the stability of the system.
Similar content being viewed by others
Abbreviations
- a :
-
Wavenumber
- c :
-
Specific heat of solid
- c p :
-
Specific heat of fluid
- d :
-
Height of the porous layer
- Da :
-
Darcy number, k/d 2
- g :
-
Gravitational acceleration (0, 0, −g)
- k :
-
Permeability of the porous layer
- l, m :
-
Horizontal wavenumbers
- Pr :
-
Prandtl number, ν/κ
- Pr D :
-
Darcy–Prandtl number, \({Pr_D = {\phi ^{2}Pr}/{Da}}\)
- p :
-
Pressure
- q :
-
Velocity vector (u, v, w)
- Ra :
-
Rayleigh number, β gΔTdk/νκ
- t :
-
Time
- T :
-
Temperature
- ΔT :
-
Temperature difference between the walls
- x, y, z :
-
Space coordinates
- β :
-
Thermal expansion coefficient
- \({\phi}\) :
-
Porosity
- ε :
-
Amplitude of modulation
- Ω:
-
Frequency of modulation
- φ :
-
Phase angle
- γ :
-
Ratio of specific heat (ρ c)m /(ρ c p )f
- κ :
-
Thermal diffusivity
- \({\bar{{\lambda}}}\) :
-
Stress relaxation parameter
- Γ:
-
Deborah number, \({{\bar{{\lambda }}\kappa }/{\phi d^{2}}}\)
- χ :
-
Normalized porosity, \({\phi /\gamma}\)
- μ :
-
Dynamic viscosity
- ν :
-
Kinematic viscosity
- ρ :
-
Density
- ω :
-
Dimensionless frequency of modulation, Ω d 2 γ/κ
- \({\nabla _1^2}\) :
-
\({\frac{\partial ^{2}}{\partial x^{2}}+\frac{\partial ^{2}}{\partial y^{2}}}\)
- \({\nabla ^{2}}\) :
-
\({\nabla _1^2 +\frac{\partial ^{2}}{\partial z^{2}}}\)
- b:
-
Basic state
- c:
-
Critical
- f:
-
Fluid
- m:
-
Porous medium
- 0:
-
Reference value
- s:
-
Solid
- *:
-
Dimensionless quantity
- ′:
-
Perturbed quantity
References
Bardan G., Mojtabi A.: On the Horton–Rogers–Lapwood convcetive instability with vertical vibration: onset of convection. Phys. Fluids 12, 2723 (2000)
Bhadauria B.S.: Thermal modulation of Rayleigh–Benard convection in a sparsely packed porous medium. J. Porous Media 10(2), 175–188 (2007)
Caltagirone J.P.: Stabilite d’une couche poreuse horizontale soumise a des conditions aux limite periodiques. Int. J. Heat Mass Transf. 19, 815–820 (1976)
Davis S.H.: The stability of time periodic flows. Ann. Rev. Fluid Mech. 8, 57–74 (1976)
Gershuni G.Z., Zhukhovitskii E.M., Iurkov I.S.: On convcetive stability in the prescence of periodically varying parameter. J. Appl. Math. Mech. 34, 442–452 (1970)
Govender S.: Stability of convection in a gravity modulated porous layer heated from below. Transp. Porous Media 57, 113 (2004)
Gresho P.M., Sani R.L.: The effect of gravity modulation on the stability of a heated fluid layer. J. Fluid Mech. 40, 783–806 (1970)
Horton C.W., Rogers F.T.: Convection currents in a porous medium. J. Appl. Phys. 16, 367–370 (1945)
Lapwood E.R.: Convection of a fluid in a porous medium. Proc. Cambridge Phil. Soc. 44, 508–521 (1948)
Lowire W.: Fundamentals of Geophysics University Press, Cambridge (1997)
Malashetty M.S., Padmavathi V.: Effect of gravity modulation on the onset of convection in porous layer. J. Porous Media 1(3), 219–226 (1997)
Malashetty M.S., Wadi V.S.: Rayleigh Benard convection subjected to time dependent wall temperature in a fluid saturated porous layer. Fluid Dyn. Res. 24, 293–308 (1999)
Malashetty M.S., Basavaraja D.: Effect of thermal/gravity modulation on the onset of convection in a horizontal anisotropic porous layer. Int. J. Appl. Mech. Eng. 8(3), 425–439 (2003)
Malashetty M.S., Basavaraja D.: Effect of time-periodic boundary temperatures on the onset of double diffusive convection in a horizontal anisotropic porous layer. Int. J. Heat Mass Transf. 47, 2317–2327 (2004)
Malashetty M.S., Basavaraja D.: Rayleigh–Benard convection subject to time dependent wall temperature/gravity in a fluid saturated anisotropic porous medium. Heat Mass Transf. 38, 551–563 (2002)
Malashetty M.S., Shivakumara I.S., Kulkarni S., Swamy M.: Convective instability of Oldroyd-B fluid saturated porous layer heated from below using a thermal non-equilibrium model. Transp. Porous Media 64, 123–139 (2006)
Malashetty M.S., Siddheshwar P.G., Swamy M.: Effect of thermal modulation on the onset of convection in a viscoelastic fluid saturated porous layer. Transp. Porous Media 62, 55–79 (2006)
Nelson, E.S.: An examination of anticipation of g-jitter on space station and its effects on materials processes, NASA TM, 103775 (1991)
Rogrers J.R., Pesch W., Brausch O., Schatz M.F.: Complex-ordered patterns in shaken convection. Phys. Rev. E. 71, 066214-1-18 (2005)
Roppo M.H., Davis S.H., Rosenblat S.: Benard convection with time periodic heating. Phys. Fluids 27, 796–803 (1984)
Rosenblat S., Herbert D.M.: Low frequency modulation of thermal instability. J. Fluid Mech. 43, 385–389 (1970)
Rosenblat S., Tannaka G.A.: Modulation of thermal convection instability. Phys. Fluids 14, 1319–1322 (1971)
Rudraiah N., Malashetty M.S.: Effect of modulation on the onset of convection in a sparsely packed porous layer. ASME J. Heat Transf. 122, 685–689 (1990)
Rudraiah N., Radhadevi P.V., Kaloni P.N.: Effect of modulation on the onset of thermal convection in a viscoelastic fluid-saturated sparsely packed porous layer. Can. J. Phys. 68, 214–221 (1990)
Saravanan S., Purusothaman A.: Floquet instability of a gravity modulated Rayleigh–Benard problem in an anisotropic porous medium. Int. J. Therm. Sci. 48, 2085 (2009)
Saravanan, S., Sivakumara, T.: Onset of filtration convection in a vibrating medium: the Brinkman model. Phys. Fluids 22, 034104(1–15) (2010)
Shivakumara I.S., Jinho Lee., Malashetty M.S., Sureshkumar S.: Effect of thermal modulation on the onset of convection in Walters B viscoelastic fluid-saturated porous medium. Transp. Porous Media 87, 291–307 (2011)
Vadasz P.: Coriolis effect on gravity-driven convection in a rotating porous layer heated from below. J. Fluid Mech. 376, 351–375 (1998)
Venezian G.: Effect of modulation on the onset of thermal convection. J. Fluid Mech. 35, 243–254 (1969)
Wadih, H., Zahibo, N., Roux, B.: Effect of gravity jitter on natural convection in a vertical cylinder. In: Koster, J.N., Sani, R.L. (eds.) Low Gravity Fluid Dynamics and Transport Phenomena, pp. 309–354. AIAA, New York (1990)
Wadih M., Roux B.: Natural convection in a long vertical cylinder under gravity modulation. J. Fluid Mech. 193, 391–415 (1988)
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Malashetty, M.S., Begum, I. Effect of Thermal/Gravity Modulation on the Onset of Convection in a Maxwell Fluid Saturated Porous Layer. Transp Porous Med 90, 889–909 (2011). https://doi.org/10.1007/s11242-011-9822-x
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11242-011-9822-x