Variable viscosity effects on combined heat and mass transfer by free convection over a truncated cone in porous media: UWT/UWC

• Autorzy: Hassanien I. A. , Essawy A. H. , Moursy N. M.
• Języki publikacji: EN

Abstrakty

EN

An analysis is presented is to study the beat and mass transfer characteristics of natural convection flow about a truncated cone embedded in a saturated porous medium with uniform surface temperature/concentration under the combined buoyancy effects thermal and mass diffusion. The transformed governing equations are solved by Keller box method. Numerical results for dimensionless temperature and concentration; the local Nuss elt (Sherwood) numbers are presented over a wide range of dimensionless distance ξ, Lewis number Le, buoyancy ratio N and the wall to ambient viscosity ratio v∗. It has been found that the local Nusselt number and Sherwood number decrease with decreasing the wall to ambient viscosity ratio v∗. Furthermore, it is shown that the local Nusselt (Sherwood) numbers of the truncated cone approach those of inclined plate (full cone) for the case of constant viscosity at ξ = 0 (ξ → ∞).

Słowa kluczowe

EN

mass; heat transfer; porous media

• Wydawca: Wydawnictwo Politechniki Łódzkiej
• Czasopismo: Mechanics and Mechanical Engineering
• Rocznik: 2002
• Tom: Vol. 6, nr 1
• Strony: 51--61
• Opis fizyczny: Bibliogr. 15 poz.

Twórcy

autor

Hassanien I. A.

• Assuit University, Faculty of Science, Department of Mathematics, Assuit, Egypt

autor

Essawy A. H.

• Minia University, Faculty of Science, Department of Mathematics, Minia, Egypt

autor

Moursy N. M.

• Minia University, Faculty of Science, Department of Mathematics, Minia, Egypt

Bibliografia

• [1] Trevisan, O.V. and Bejan N.: Combined heat and mass transfer by natural convection in a porous medium, Adv. Heat Transfer, 20, (1990), 315-352.
• [2] Bejan, A. and Khair, N.R.: Heat and mass transfer by natural convection in a porous medium, Int. J. Heat Mass Transfer, 28, (1985), 909-918.
• [3] Singh, P. and Queeny, Q.: Free convection heat and mass transfer along a vertical surface in a porous medium, Acta Mechanica, 123, (1997), 69-73.
• [4] Lai, F.C., Choi, C.Y., Kułacki, F.A.: Coupled heat and mass transfer by natural convection from slender bodies of revolution in porous media, Int. Comm. Heat and Mass Transfer, 17, (1990), 609-920.
• [5] Yih, K.A.: Coupled heat and mass transfer by free convection over a truncated cone in porous media: VWT/VWC or VHF/VMF, Acta Mechanica, 137, (1999), 83-97.
• [6] Kassoy, D.R. and Zebib, A.: Variable viscosity effects on the onset of convection in porous media, Physics Fluids, 18, (1975), 1649-1651.
• [7] Straus, J.M. and Schubert, G.: Thermal convection of water in a porous medium: effects of temperature and pressure dependent thermodynamic and transport properties, J. Geophys. Res., 82, (1977), 325-333.
• [8] Horne, R.N. and O’Sullivan, M. J.: Convection in a porous medium heated from below: the effect of temperature dependent viscosity and thermal expansion coefficient, J. Heat Transfer, 100, (1978), 448-452.
• [9] Gary, J., Kassoy, D.R., Tadjeran, H. and Zebib, A.: The effect of significant viscosity variation on convective heat transport in water-saturated porous media, J. Fluid Mech., 117, (1982), 233-249.
• [10] Blythe, P.A. and Simpkins, P.G.: Convection in porous layer for a temperature dependent viscosity, Int. J. Heat Mass Transfer, 24, (1981), 497-506.
• [11] Ramrez, N.E. and Sącz, A.E.: The effect of variable viscosity on boundary-layer heat transfer in a porous medium, Int. Comm. Heat Mass Transfer, 17, (1990), 477-488.
• [12] Lai, F.C. and Kułacki, F.A.: The effect of variable viscosity on convective heat transfer along a vertical surface in a saturated porous medium, Int. J. Heat Mass Transfer, 33, (1990), 1028-1031.
• [13] Jang, J.Y. and Leu, J.S.: Variable viscosity effects on the vortex instability of free convection boundary layer over о horizontal surface in a porous medium, Int. J. Heat Mass Transfer, 38, (1993), 1287-1294.
• [14] Cheng, P., Le, T.T. and Pop, I.: Natural convection of a Darcian fluid about a cone, Int. Comm. Heat Mass Transfer, 12, (1977), 705-717.
• [15] Hassanien, I.A. and Omar, G.M.: Variable permeability effects on mixed convection along a vertical wedge embedded in a porous medium with variable surface heat flux, Appl. Math, and Computation, (2002), in press.