Abstract
The onset of Rayleigh–Bénard convection of variable-viscosity Newtonian dielectric liquid confined between two parallel plates is subject to free-free isothermal boundary condition. The combined and individual effects of temperature-dependent and electric-field-dependent variable-viscosity along with the internal heat generation are studied using the higher order Galerkin technique. This theoretical study shows that even a mild temperature-dependent variable-viscosity destabilizes the system and the electric-field-dependent variable-viscosity stabilizes the system both in the absence/presence of heat source/sink.
Similar content being viewed by others
Availability of data and material
Not applicable.
Abbreviations
- a :
-
Wave number
- \(\vec {D}\) :
-
Electric displacement
- \(\vec {E}\) :
-
Electric field
- \(\vec {E_{0}}\) :
-
Reference electric field
- g :
-
Gravitational acceleration (0, 0, − g)
- \(\vec {P}\) :
-
Dielectric polarization
- q :
-
Velocity vector components (u, v, w)
- e :
-
Positive free charge
- p :
-
Effective pressure
- T :
-
Temperature
- \(T_{0}\) :
-
Reference temperature
- \(V_T\) :
-
Temperature dependent variable viscosity
- \(V_E\) :
-
Electric field dependent variable viscosity
- Tr :
-
Transpose
- \(R_I\) :
-
Internal Rayleigh number
- t :
-
Time
- \( \alpha \) :
-
Thermal expansion coefficient
- \( \epsilon _{0}\) :
-
Electric permittivity
- \( \epsilon _{r}\) :
-
Relative permittivity
- \( \kappa _{1} \) :
-
Thermal conductivity
- \( \phi \) :
-
Electric potential
- \(\mu \) :
-
Temperature and electric field dependent viscosity
- \(\rho \) :
-
Fluid density
- \(\rho _0 \) :
-
Reference density at \(T=T_{0}\)
- \(\chi _{e}\) :
-
Electric susceptibility
- b :
-
Basic state
- c :
-
Critical quantity
- \('\) :
-
Dimensional quantity
- *:
-
Dimensionless quantity
References
Hughes, W.F., Young, F.J.: Electromagnetodynamics of Fluids. Wiley, New York (1966)
Turnbull, R.J.: Electroconvective instability with a stabilizing temperature gradient. I. Theory. Phys. Fluids 11, 2588–2596 (1968a)
Turnbull, R.J.: Electroconvective instability with a stabilizing temperature gradient. II. Experimental results. Phys. Fluids 11, 2597–2612 (1968b)
Turnbull, R.J.: Effect of dielectrophoretic forces on the Bénard instability. Phys. Fluids 12, 1809–1815 (1969)
Bradley, R.: Overstable electroconvective instabilities. Q. J. Mech. Appl. Math. 31, 381–390 (1978)
Takashima, M., Ghosh, A.K.: Electrohydrodynamic instability in a viscoelastic liquid layer. J. Phys. Soc. Jpn. 47, 1717–1722 (1979)
Castellanos, A., Velarde, M.G.: Electrohydrodynamic stability in the presence of a thermal gradient. Phy. Fluids 24, 1784–1786 (1981)
Melcher, J.R.: Continuum Electromechanics. M. I. T. Press, Cambridge (1981)
Takashima, M., Hamabata, H.: Stability of natural convection in a vertical layer of dielectric fluid in the presence of a horizontal ac electric field. J. Phys. Soc. Jpn. 149, 1728–1736 (1984)
Ko, H.J., Kim, M.U.: Electrohydrodynamic convective instability in a horizontal fluid layer with temperature gradient. J. Phys. Soc. Jpn. 57, 1650–1661 (1988)
Nield, D.A.: The effect of temperature-dependent viscosity on the onset of convection in a saturated porous medium. ASME J. Heat Transf. 118, 803–805 (1996)
Chamkha, A.J.: Effects of heat generation/absorption and thermophoresis on hydromagnetic flow with heat and mass transfer over a flat surface. Int. J. Numer. Methods Fluid Flow 10, 432–439 (2000)
Othman, M.I.A., Sweilam, N.H.: Electrohydrodynamic instability in a horizontal viscoelastic fluid layer in the presence of internal heat generation. Can. J. Phys. 80, 697–705 (2002)
Siddheshwar, P.G.: Oscillatory convection in viscoelastic, ferromagnetic/dielectric liquids. Int. J. Mod. Phys. B. 16(17–18), 2629–2635 (2002)
Shobha, B.: Effect of variable viscosity on free convection over a non-isothermal axisymmetric body in a porous medium with internal heat generation. Acta Mech. 169, 187–194 (2004)
Siddheshwar, P.G., Annamma, A.: Rayleigh–Bénard convection in a dielectric liquid: time periodic body force. PAMM 7(1), 2100083–2100084 (2007)
Shivakumara, I.S., Nagashree, M.S., Hemalatha, K.: Electroconvective instability in a heat generating dielectric fluid layer. Int. Commun. Heat Mass Transf. 34, 1041–1047 (2007)
Siddheshwar, P.G., Annamma, A.: Rayleigh–Bénard convection in a dielectric liquid: imposed time periodic boundary temperatures. Chamchuri J. Math. 1(2), 105–121 (2009)
He, J.H.: Homotopy perturbation method for solving boundary value problems. Phys. Lett. A 350(1–2), 87–88 (2006)
Siddheshwar, P.G., Ramachandramurty, V., Uma, D.: Rayleigh–Bénard and Marangoni magnetoconvection in Newtonian liquid with thermorheological effects. Int. J. Eng. Sci. 49, 1078–1094 (2011)
Siddheshwar, P.G., Radhakrishna, D.: Linear and nonlinear electroconvection under AC electric field. J. Commun. Nonlinear Sci. Numer. Simul. 17, 2883–2895 (2012)
Siddheshwar, P.G., Revathi, B.R.: Effect of gravity modulation on weakly nonlinear stability of stationary convection in a dielectric liquid. World Acad. Sci. Eng. Technol. 7(1), 119–124 (2013)
Maruthamanikandan, S., Smita, S.N.: Convective heat transfer in Maxwell–Cattaneo dielectric fluids. IJCER 3, 347–355 (2013)
Sekhar, G.N., Jayalatha, G., Prakash, R.: Thermal convection in variable viscosity ferromagnetic liquids with heat source. Int. J. Appl. Comput. Math. 3(4), 3539–3559 (2017)
Maria, T., Sangeetha, G.: Effect of gravity modulation and internal heat generation on Rayleigh–Bénard convection in couple stress fluid with Maxwell–Cattaneo law. Int. J. Appl. Eng. Res. 13, 2688–2693 (2018)
Siddheshwar, P.G., Uma, D., Bhavya, S.: Effects of variable viscosity and temperature modulation on linear Rayleigh–Bénard convection in Newtonian dielectric liquid. Appl. Math. Mech. (English Edition) 40(11), 1601–1614 (2019)
Siddheshwar, P.G., Uma, D., Bhavya Shivaraj.: Linear and non-linear stability of thermal convection in Newtonian dielectric liquid with field dependent viscosity. Eur. Phys. J. Plus 135(2), 1–15 (2020)
Acknowledgements
Thanks are extended to the two reviewers and the Editor for providing helpful suggestions for bringing the paper to the present form.
Funding
There was no funding support for the work reported in the paper.
Author information
Authors and Affiliations
Contributions
PGS formulated the problem, helped in the research methodology and the writing of the paper, BSR worked out the paper, did the computations and participated in the finalization of the paper, DU participated in the preparation of various versions of the paper. All authors read and approved the final manuscript.
Corresponding author
Ethics declarations
Conflict of interest
The authors declare that they have no competing interests.
Additional information
Publisher's Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Rights and permissions
About this article
Cite this article
Shivaraj, B., Siddheshwar, P.G. & Uma, D. Effects of Variable Viscosity and Internal Heat Generation on Rayleigh–Bénard Convection in Newtonian Dielectric Liquid. Int. J. Appl. Comput. Math 7, 119 (2021). https://doi.org/10.1007/s40819-021-01060-z
Accepted:
Published:
DOI: https://doi.org/10.1007/s40819-021-01060-z