Abstract
Our present work studies the impacts of variable porosity and variable permeability on the transient buoyancy-induced heat transmission flow of Cu–H2O nanofluid through a holey medium (glass bead, aluminum foam and sandstone) inside a right-angle trapezoidal cavity considering thermal nonequilibrium states amid the solid matrix and the nanofluid. We carried out numerical simulation by utilizing the Galerkin finite element method. We explored the impacts of the different model parameters on the thermal characteristics in details. The obtained numerical results confirm that the critical Rayleigh number, \( {\text{Ra}}_{\text{c}} \), determining the thermal nonequilibrium state increased by increasing the Nield number, whereas it is found to be diminished with the increase in the diameter of the beads constructing the porous medium as well as with the porosity parameter. Additionally, the average Nusselt number in a porous medium having variable porosity is found to be higher compared to the medium of the uniform porosity. Increasing the variable porosity can significantly (more than 500%) increase the rate of heat transfer of the nanofluid in a porous medium. The higher porosity of the medium enhances the thermal state of a system to make it thermal nonequilibrium from the thermal equilibrium state. Furthermore, nanofluid flow in glass bead porous medium provides maximum (5% and 14% increase compared to the sandstone and aluminum foam, respectively) heat transmission rate.
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Abbreviations
- \( A_{1} \) :
-
Aspect ratio
- \( A_{2} \) :
-
Aspect ratio
- \( c_{1} \) :
-
Empirical constant
- \( c_{2} \) :
-
Empirical constant
- \( C_{\text{p}} \) :
-
Specific heat (J/kg K)
- Da:
-
Darcy number
- \( d_{\text{p}} \) :
-
Solid particles diameter in the porous medium (m)
- \( D_{\text{p}} \) :
-
Dimensionless solid particles diameter in the porous medium
- \( g \) :
-
Acceleration as a result of gravity (m/s2)
- \( h \) :
-
Interface heat transmission coefficient among the nanofluid and solid matrix (kg/ms)
- \( H \) :
-
Height of the cavity (m)
- \( K \) :
-
Permeability (m2)
- \( l \) :
-
Length of the upper wall (m)
- \( L \) :
-
Length of the lowest wall (m)
- Ni:
-
Nield number
- Mu:
-
Nusselt number
- \( p \) :
-
Dimensional pressure (Pa)
- \( P \) :
-
Non-dimensional pressure
- Ra:
-
Rayleigh number
- \( {\text{Ra}}_{\text{c}} \) :
-
Critical Rayleigh number
- \( t \) :
-
Dimensional time (s)
- \( T \) :
-
Temperature (K)
- \( T_{0} \) :
-
Reference temperature (K)
- \( T_{\text{h}} \) :
-
Temperature of the hot wall (K)
- \( T_{\text{c}} \) :
-
Temperature of the cold wall (K)
- \( (u,v) \) :
-
Dimensional velocity components (m/s)
- \( (U,V) \) :
-
Non-dimensional velocity components
- \( (x,y) \) :
-
Dimensional coordinates (m)
- \( (X,Y) \) :
-
Non-dimensional coordinates
- \( \alpha \) :
-
Thermal diffusivity (m/s2)
- \( \beta \) :
-
Coefficient of volume expansion (1/K)
- \( \tau \) :
-
Nondimensional time
- \( \rho \) :
-
Fluid density (kg/m3)
- \( \mu \) :
-
Dynamic viscosity (Pa)
- \( \upsilon \) :
-
Kinematic coefficient of viscosity (m/s2)
- \( \theta \) :
-
Non-dimensional temperature
- \( \phi \) :
-
Nanoparticle volume fraction
- \( \kappa \) :
-
Thermal conductivity (W/m K)
- \( \lambda \) :
-
Ratio of diffusivities
- \( \varepsilon \), \( \varepsilon^{*} \) :
-
Porosity
- \( \varepsilon_{\infty } \) :
-
Uniform porosity
- \( \delta \) :
-
Ratio of conductivities
- nf :
-
Nanofluid
- \( bf \) :
-
Base fluid
- \( sp \) :
-
Solid particles
- \( s \) :
-
Solid matrix
- \( t \), \( \tau \) :
-
Partial derivative w.r.t. \( t \), \( \tau \)
- \( x \), \( X \) :
-
Partial derivative w.r.t. \( x \), \( X \)
- \( y \), \( Y \) :
-
Partial derivative w.r.t. \( y \), Y
- h :
-
Hot
- c :
-
Cold
References
Rahman, M.M.; Rosca, A.V.; Pop, I.: Boundary layer flow of a nanofluid past a permeable exponentially shrinking surface with convective boundary condition using Buongiorno’s model. Int. J. Numer. Methods Heat Fluid Flow 25(2), 299–319 (2015)
Rahman, M.M.; Al-Rashdi, M.H.; Pop, I.: Convective boundary layer flow and heat transfer in a nanofluid in the presence of second order slip, constant heat flux and zero nanoparticles flux. Nucl. Eng. Des. 297, 95–103 (2016)
Uddin, M.J.; Alam, M.S.; Rahman, M.M.: Natural convective heat transfer flow of nanofluids inside a quarter-circular enclosure using nonhomogeneous dynamic model. Arab. J. Sci. Eng. 42(5), 1883–1901 (2017)
Uddin, M.J.; Alam, M.S.; Al-Salti, N.; Rahman, M.M.: Investigations of natural convection heat transfer in nanofluids filled horizontal semicircular-annulus using nonhomogeneous dynamic model. Am. J. Heat Mass Transf. 3(6), 425–452 (2016)
Al-Weheibi, S.M.; Rahman, M.M.; Alam, M.S.; Vajravelu, K.: Numerical simulation of natural convection heat transfer in a trapezoidal enclosure filled with nanoparticles. Int. J. Mech. Sci. 131, 599–612 (2017)
Chen, H.; Witharana, S.; Jina, Y.; Kimd, C.; Dinga, Y.: Predicting thermal conductivity of liquid suspensions of nanoparticles (nanofluids) based on Rheolog. Particuology 7(2), 151–157 (2009)
Mansour, M.A.; Ahmed, S.E.; Rashad, A.M.: MHD natural convection in a square enclosure using nanofluid with the influence of thermal boundary conditions. J. Appl. Fluid Mech. 9(5), 2515–2525 (2016)
Rashad, A.M.; Sivasankaran, S.; Mansour, M.A.; Bhuvaneswari, M.: Magneto-convection of nanofluids in a lid-driven trapezoidal cavity with internal heat generation and discrete heating. Numer. Heat Transf. Part A Appl. 71(12), 1223–1234 (2017)
Cheng, P.: Heat transfer in geothermal systems. Adv. Heat Transf. 14, 1–105 (1979)
Nield, D.A.; Bejan, A.: Convection in Porous Media, 4th edn. Springer, New York (2013)
Rashidi, M.M.; Basiriparsa, A.; Shamekhi, L.; Momoniat, E.: Entropy generation analysis of the revised Cheng–Minkowycz problem for natural convective boundary layer flow of nanofluid in a porous medium. Therm. Sci. 19, 169–178 (2015)
Rashidi, M.M.; Erfani, E.: The modified differential transforms method for investigating nano boundary-layers over stretching surfaces. Int. J. Numer. Methods Heat Fluid Flow 21, 864–883 (2011)
Rashidi, M.M.; Momoniat, E.; Ferdows, M.; Basiriparsa, A.: Lie group solution for free convective flow of a nanofluid past a chemically reacting horizontal plate in a porous media. Math. Probl. Eng., Article ID 239082 (2014)
Ingham, D.B.; Pop, I. (eds.): Transport Phenomena in Porous Media, vol. 3. Elsevier, Oxford (2005)
Vafai, K.: Hand book of Porous Media, 2nd edn. Taylor & Francis, New York (2005)
Vafai, K. (ed.): Porous Media: Applications in Biological Systems and Biotechnology. CRC Press, Tokyo (2010)
Vadasz, P. (ed.): Emerging Topics in Heat and Mass Transfer in Porous Media: From Bioengineering and Microelectronics to Nanotechnology, vol. 22. Springer, New York (2008)
Al-Amiri, A.M.: Natural convection in porous enclosures: the application of the two-energy equation model. Numer. Heat Transf. Part A Appl. 41(8), 817–834 (2002)
Baytas, A.C.; Pop, I.: Free convection in a square porous cavity using a thermal non-equilibrium model. Int. J. Therm. Sci. 41(9), 861–870 (2002)
Baytas, A.C.: Thermal non-equilibrium natural convection in a square enclosure filled with a heat-generating solid phase, non-Darcy porous medium. Int. J. Energy Res. 27(10), 975–988 (2003)
Kasaeian, A.; Daneshazarian, R.; Mahian, O.; Kolsi, L.; Chamkha, A.J.; Wongwises, S.; Pop, I.: Nanofluid flow and heat transfer in porous media: a review of the latest developments. Int. J. Heat Mass Transf. 107, 778–791 (2017)
Sheikholeslami, M.; Ganji, D.D.: Numerical investigation of nanofluid transportation in a curved cavity in existence of magnetic source. Chem. Phys. Lett. 667, 307–316 (2017)
Sheikholeslami, M.; Nimafar, M.; Ganji, D.D.; Pouyandehmehr, M.: CuO–H2O nanofluid hydrothermal analysis in a complex shaped cavity. Int. J. Hydrog. Energy 41(40), 17837–17845 (2016)
Beukema, K.J.; Bruin, S.; Schenk, J.: Three-dimensional natural convection in a confined porous medium with internal heat generation. Int. J. Heat Mass Transf. 26(3), 451–458 (1983)
Haajizadeh, M.; Ozguc, A.F.; Tien, C.L.: Natural convection in a vertical porous enclosure with internal heat generation. Int. J. Heat Mass Transf. 27(10), 1893–1902 (1984)
Kim, G.B.; Hyun, J.M.: Buoyant convection of a power-law fluid in an enclosure filled with heat-generating porous media. Numer. Heat Transf. Part A Appl. 45(6), 569–582 (2004)
Prasad, V.: Thermal convection in a rectangular cavity filled with a heat-generating, Darcy porous medium. J. Heat Transf. 109(3), 697–703 (1987)
Wu, F.; Wang, G.; Zhou, W.: Natural convection in a cavity filled with porous medium with partially thermal active sidewalls under local thermal nonequilibrium conditions. J. Porous Media 17(11), 983–997 (2014)
Wu, F.; Wang, G.; Zhou, W.: A thermal nonequilibrium approach to natural convection in a square enclosure due to the partially cooled sidewalls of the enclosure. Numer. Heat Transf. Part A Appl. 67(7), 771–790 (2015)
Mohan, C.G.; Satheesh, A.: The numerical simulation of double-diffusive mixed convection flow in a lid-driven porous cavity with magnetohydrodynamic effect. Arab. J. Sci. Eng. 41(5), 1867–1882 (2016)
Rashad, A.M.; Gorla, R.S.R.; Mansour, M.A.; Ahmed, S.E.: Magnetohydrodynamic effect on natural convection in a cavity filled with a porous medium saturated with nanofluid. J. Porous Media 20(4), 363–379 (2017)
Rashad, A.M.; Rashidi, M.M.; Lorenzini, G.; Ahmed, S.E.; Aly, A.M.: Magnetic field and internal heat generation effects on the free convection in a rectangular cavity filled with a porous medium saturated with Cu–water nanofluid. Int. J. Heat Mass Transf. 104, 878–889 (2017)
Chamkha, A.J.; Rashad, A.M.; Armaghani, T.; Mansour, M.A.: Effects of partial slip on entropy generation and MHD combined convection in a lid-driven porous enclosure saturated with a Cu–water nanofluid. J. Therm. Anal. Calorim. 132(2), 1291–1306 (2018)
Rashad, A.M.; Armaghani, T.; Chamkha, A.J.; Mansour, M.A.: Entropy generation and MHD natural convection of a nanofluid in an inclined square porous cavity: effects of a heat sink and source size and location. Chin. J. Phys. 56(1), 193–211 (2018)
Bejan, A.: Convective Heat Transfer in Porous Media. Handbook of Single-Phase Convective Heat Transfer. Chapter 16. Wiley, New York (1987)
Nield, D.A.: Modeling fluid flow in saturated porous media and at interfaces. In Transport Phenomena in Porous Media II, pp. 1–19 (2002)
Lage, J.L.; Weinert, A.K.; Price, D.C.; Weber, R.M.: Numerical study of a low permeability microporous heat sink for cooling phased-array radar systems. Int. J. Heat Mass Transf. 39(17), 3633–3647 (1996)
Kim, S.J.; Kim, D.; Lee, D.Y.: On the local thermal equilibrium in microchannel heat sinks. Int. J. Heat Mass Transf. 43(10), 1735–1748 (2000)
Jiang, P.X.; Fan, M.H.; Si, G.S.; Ren, Z.P.: Thermal–hydraulic performance of small scale micro-channel and porous-media heat-exchangers. Int. J. Heat Mass Transf. 44(5), 1039–1051 (2001)
Fichot, F.; Duval, F.; Tregoures, N.; Béchaud, C.; Quintard, M.: The impact of thermal non-equilibrium and large-scale 2D/3D effects on debris bed reflooding and coolability. Nucl. Eng. Des. 236(19–21), 2144–2163 (2006)
Damm, D.L.; Fedorov, A.G.: Local thermal non-equilibrium effects in porous electrodes of the hydrogen-fueled SOFC. J. Power Sources 159(2), 1153–1157 (2006)
Deléglise, M.; Binétruy, C.; Castaing, P.; Krawczak, P.: Use of non local equilibrium theory to predict transient temperature during non-isothermal resin flow in a fibrous medium. Int. J. Heat Mass Transf. 50(11–12), 2317–2324 (2007)
Hayes, A.M.; Khan, J.A.; Shaaban, A.H.; Spearing, I.G.: The thermal modeling of a matrix heat exchanger using a porous medium and the thermal non-equilibrium model. Int. J. Therm. Sci. 47(10), 1306–1315 (2008)
Lefebvre, L.P.; Banhart, J.; Dunand, D.C.: Porous metals and metallic foams: current status and recent developments. Adv. Eng. Mater. 10(9), 775–787 (2008)
Salas, K.I.; Waas, A.M.: Convective heat transfer in open cell metal foams. J. Heat Transf. 129(9), 1217–1229 (2007)
Ye, C.; Li, B.; Sun, W.: Quasi-steady-state and steady-state models for heat and moisture transport in textile assemblies. Proc. R. Soc. A Math. Phys. Eng. Sci. 466(2122), 2875–2896 (2010)
Straughan, B.: Tipping points in Cattaneo–Christov thermohaline convection. Proc. R. Soc. A Math. Phys. Eng. Sci. 467(2125), 7–18 (2010)
Haji-Sheikh, A.; Minkowycz, W.J.: Heat transfer analysis under local thermal non-equilibrium conditions. In: Emerging Topics in Heat and Mass Transfer in Porous Media. Springer, Dordrecht, pp. 39–62 (2008)
Hossain, M.A.; Wilson, M.: Natural convection flow in a fluid-saturated porous medium enclosed by non-isothermal walls with heat generation. Int. J. Therm. Sci. 41(5), 447–454 (2002)
Bourantas, G.C.; Skouras, E.D.; Loukopoulos, V.C.; Burganos, V.N.: Heat transfer and natural convection of nanofluids in porous media. Eur. J. Mech. B Fluids 43, 45–56 (2014)
Wu, F.; Zhou, W.; Ma, X.: Natural convection in a porous rectangular enclosure with sinusoidal temperature distributions on both side walls using a thermal non-equilibrium model. Int. J. Heat Mass Transf. 85, 756–771 (2015)
Sheremet, M.A.; Pop, I.; Nazar, R.: Natural convection in a square cavity filled with a porous medium saturated with a nanofluid using the thermal nonequilibrium model with a Tiwari and Das nanofluid model. Int. J. Mech. Sci. 100, 312–321 (2015)
Tiwari, R.K.; Das, M.K.: Heat transfer augmentation in a two-sided lid-driven differentially heated square cavity utilizing nanofluids. Int. J. Heat Mass Transf. 50(9–10), 2002–2018 (2007)
Sheikholeslami, M.; Shehzad, S.A.: Simulation of water based nanofluid convective flow inside a porous enclosure via non-equilibrium model. Int. J. Heat Mass Transf. 120, 1200–1212 (2018)
Mehryan, S.A.M.; Izadi, M.; Sheremet, M.A.: Analysis of conjugate natural convection within a porous square enclosure occupied with micropolar nanofluid using local thermal non-equilibrium model. J. Mol. Liq. 250, 353–368 (2018)
Al-Weheibi, S.M.; Rahman, M.M.: Convective heat transmission inside a porous trapezoidal enclosure occupied by nanofluids: local thermal nonequilibrium conditions for a porous medium. Ital. J. Eng. Sci. Tecn. Ital. 61+1(2), 102–114 (2018)
David, E.; Lauriat, G.; Cheng, P.: Natural convection in rectangular cavities filled with variable porosity media. In: 25th National Heat Transfer Conference, ASME, vol. 1, pp. 605–612 (1988)
Marcondes, F.; Medeiros, J.M.; Gurgel, J.M.: Numerical analysis of natural convection in cavities with variable porosity. Numer. Heat Transf. Part A 40(4), 403–420 (2001)
Mohammadein, A.A.; El-Shaer, N.A.: Influence of variable permeability on combined free and forced convection flow past a semi-infinite vertical plate in a saturated porous medium. Heat Mass Transf. 40, 341–346 (2004)
Pal, D.; Shivakumara, I.S.: Mixed convection heat transfer from a vertical heated plate embedded in a sparsely packed porous medium. Appl. Mech. Eng. 11(4), 929–939 (2006)
Abelman, S.; Parsa, A.B.; Sayehvand, H.O.: Nanofluid flow and heat transfer in a Brinkman porous channel with variable porosity. Quaest. Math. 41(4), 449–467 (2018)
Brinkman, H.C.: A calculation of the viscous force exerted by a flowing fluid on a dense swarm of particles. Flow Turbul. Combust. 1(1), 27 (1949)
Brinkman, H.C.: On the permeability of media consisting of closely packed porous particles. Flow Turbul. Combust. 1(1), 81 (1949)
Ochoa-Tapia, J.A.; Whitaker, S.: Momentum transfer at the boundary between a porous medium and a homogeneous fluid—II. Comparison with experiment. Int. J. Heat Mass Transf. 38(14), 2647–2655 (1995)
Chandrasekhara, B.C.; Vortmeyer, D.: Flow model for velocity distribution in fixed porous beds under isothermal conditions. Wärme-und Stoffübertragung 12(2), 105–111 (1979)
Hsu, C.T.; Cheng, P.: Closure schemes of the macroscopic energy equation for convective heat transfer in porous media. Int. Commun. Heat Mass Transf. 15(5), 689–703 (1988)
Ergun, S.: Fluid flow through packed columns. Chem. Eng. Sci. 48(2), 89–94 (1952)
Brinkman, H.C.: The viscosity of concentrated suspensions and solutions. J. Chem. Phys. 20(4), 571 (1952)
Maxwell, J.C.: A Treatise on Electricity and Magnetism, vol. I, II. Clarendon Press, Oxford (1873)
Oztop, H.F.; Abu-Nada, E.: Numerical study of natural convection in partially heated rectangular enclosures filled with nanofluids. Int. J. Heat Fluid Flow 29(5), 1326–1336 (2008)
Al-Kalbani, K.S.; Alam, M.S.; Rahman, M.M.: Finite element analysis of unsteady natural convective heat transfer and fluid flow of nanofluids inside a tilted square enclosure in the presence of oriented magnetic field. Am. J. Heat Mass Transf. 3, 186–224 (2016)
Uddin, M.J.; Rahman, M.M.: Numerical computation of natural convective heat transport within nanofluids filled semi-circular shaped enclosure using nonhomogeneous dynamic model. Therm. Sci. Eng. Prog. 1, 25–38 (2017)
Zienkiewicz, O.C.; Taylor, R.L.; Zienkiewicz, O.C.; Taylor, R.L.: The Finite Element Method, vol. 36. McGraw-Hill, London (1977)
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This study was funded by the research Grant IG/SCI/DOMS/18/10.
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Al-Weheibi, S.M., Rahman, M.M. & Saghir, M.Z. Impacts of Variable Porosity and Variable Permeability on the Thermal Augmentation of Cu–H2O Nanofluid-Drenched Porous Trapezoidal Enclosure Considering Thermal Nonequilibrium Model. Arab J Sci Eng 45, 1237–1251 (2020). https://doi.org/10.1007/s13369-019-04234-6
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DOI: https://doi.org/10.1007/s13369-019-04234-6