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Effects of temperature dependent fluid properties and variable Prandtl number on the transient convective flow due to a porous rotating disk

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Abstract

In this paper we have studied the effects of temperature dependent fluid properties such as density, viscosity and thermal conductivity and variable Prandtl number on unsteady convective heat transfer flow over a porous rotating disk. Using similarity transformations we reduce the governing nonlinear partial differential equations for flow and heat transfer into a system of ordinary differential equations which are then solved numerically by applying Nachtsheim–Swigert shooting iteration technique along with sixth-order Runge–Kutta integration scheme. Comparison with previously published work for steady case of the problem were performed and found to be in very good agreement. The obtained numerical results show that the rate of heat transfer in a fluid of constant properties is higher than in a fluid of variable properties. The results further show that consideration of Prandtl number as constant within the boundary layer for variable fluid properties lead unrealistic results. Therefore, modeling thermal boundary layers with temperature dependent fluid properties Prandtl number must treated as variable inside the boundary layer.

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Abbreviations

a, b :

Constants

Cf :

Skin-friction coefficient

c p :

Specific heat at constant pressure

d :

Constant

F :

Dimensionless radial velocity

G :

Dimensionless tangential velocity

H :

Dimensionless axial velocity

Nu :

Nusselt number

p :

Pressure within the boundary layer

p :

Pressure of the ambient fluid

Pr:

Variable Prandtl number

Pr :

Ambient Prandtl number

q w :

Surface heat flux

R :

Rotational parameter

Re:

Rotational Reynolds number

r :

Cylindrical radial coordinate

t :

Time

T :

Temperature within the boundary layer

T w :

Temperature at the surface of the disk

T :

Temperature of the ambient fluid

u, v, w :

Velocities along radial, tangential and axial direction, respectively

w s :

Non-dimensional suction/injection velocity

w w :

Dimensional suction/injection velocity

z :

Cylindrical vertical coordinate

γ :

Relative temperature difference parameter

ρ :

Density of the fluid

ρ :

Density of the ambient fluid

μ :

Coefficient of dynamic viscosity

μ :

Dynamic viscosity of the ambient fluid

κ :

Thermal conductivity

κ :

Thermal conductivity of the ambient fluid

η :

Similarity variable

υ :

Kinematic viscosity of the ambient fluid

δ :

Time dependent length scale

λ :

Unsteadiness parameter

φ :

Tangential coordinate

τ r :

Radial shear stress

τ t :

Tangential shear stress

θ :

Dimensionless temperature

Ω:

Angular velocity

References

  1. von Karman T (1921) Uber laminare und turbulente reibung. ZAMM 1(4):233–235

    Article  ADS  MATH  Google Scholar 

  2. Cochran WG (1934) The flow due to a rotating disk. Proc Camb Philos Soc 30(3):365–375

    Article  ADS  MATH  Google Scholar 

  3. Benton ER (1966) On the flow due to a rotating disk. Fluid Mech 24(4):781–800

    Article  ADS  MATH  Google Scholar 

  4. Millsaps K, Pohlhausen K (1952) Heat transfer by laminar flow from a rotating disk. J Aeronaut Sci 19:120–126

    MathSciNet  MATH  Google Scholar 

  5. Sparrow EM, Gregg JL (1960) Mass transfer flow and heat transfer about a rotating disk. ASME J Heat Transf 82(4):294–302

    Article  Google Scholar 

  6. Attia HA (1998) Unsteady MHD flow near a rotating porous disk with uniform suction or injection. Fluid Dyn Res 23:283–290

    Article  ADS  Google Scholar 

  7. Maleque KA, Sattar MA (2003) Transient convective flows due to a rotating disc with magnetic field and heat absorption. J Energy Heat Mass Transf 25:279–291

    Google Scholar 

  8. Zakerullah M, Ackroyd JAD (1979) Laminar natural convection boundary layers on horizontal circular disks. J Appl Math Phys 30:427–435

    Article  MATH  Google Scholar 

  9. Herwig H, Klemp K (1988) Variable properties effects of fully developed laminar flow in concentric annuli. ASME J Heat Transf 110:314–320

    Article  Google Scholar 

  10. Maleque KA, Sattar MA (2002) The effects of Hall current and variable viscosity on an unsteady MHD laminar convective flow due to a rotating disk. J Energy Heat Mass Transf 24:335–348

    Google Scholar 

  11. Attia HA (2006) Unsteady flow and heat transfer of viscous incompressible fluid with temperature dependent viscosity due to a rotating disk in a porous medium. J Phys A: Math Gen 39:979–991

    Article  ADS  MathSciNet  MATH  Google Scholar 

  12. Maleque KA, Sattar MA (2005) The effects of variable fluid properties and Hall current on the steady MHD laminar convective flow due to a porous rotating disk. Int J Heat Mass Transf 48:4963–4972

    Article  MATH  Google Scholar 

  13. Rahman MM (2010) Convective hydromagnetic slip flow with variable properties due to a porous rotating disk. Sultan Qaboos Univ J Sci 15:55–79

    Google Scholar 

  14. Rahman MM, Postelnicu A (2010) Effects of thermophoresis on the forced convective laminar flow of a viscous incompressible fluid over a rotating disk. Mech Res Commun 37:598–603

    Article  MATH  Google Scholar 

  15. Pantokratoras A (2005) Forced and mixed convection boundary layer flow along a flat plate with variable viscosity and variable Prandtl number, new results. Heat Mass Transf 41:1085–1094

    Article  ADS  Google Scholar 

  16. Pantokratoras A (2007) Non-Darcian forced convection heat transfer over a flat plate in a porous medium with variable viscosity and variable Prandtl number. J Porous Media 10:201–208

    Article  Google Scholar 

  17. Rahman MM, Rahman MA, Samad MA, Alam MS (2009) Heat transfer in micropolar fluid along a non-linear stretching sheet with temperature dependent viscosity and variable wall temperature. Int J Thermophys 30:1649–1670

    Article  ADS  Google Scholar 

  18. Rahman MM, Salauddin KM (2010) Study of hydromagnetic heat and mass transfer flow over an inclined heated surface with variable viscosity and electric conductivity. Commun Nonlinear Sci Numer Simul 15:2073–2085

    Article  ADS  MATH  Google Scholar 

  19. Rahman MM, Aziz A, Al-Lawatia M (2010) Heat transfer in micropolar fluid along a inclined permeable plate with variable fluid properties. Int J Therm Sci 49:993–1002

    Article  Google Scholar 

  20. Rahman MM, Eltayeb IA (2011) Convective slip flow of rarefied fluids over a wedge with thermal jump and variable transport properties. Int J Therm Sci 50:379–468

    Article  Google Scholar 

  21. Jayaraj S (1995) Thermophoresis in laminar flow over cold inclined plates with variable properties. Heat Mass Transf 40:167–174

    Article  ADS  Google Scholar 

  22. Sattar MA, Hossain MM (1992) Unsteady hydromagnetic free convection flow with hall current and mass transfer along an accelerated porous plate with time dependent temperature and concentration. Can J Phys 70:369–374

    Article  ADS  Google Scholar 

  23. Rahman ATMM, Alam MS, Chowdhury MK (2012) Thermophoresis particle deposition on unsteady two-dimensional forced convective heat and mass transfer flow along a wedge with variable viscosity and variable Prandtl number. Int Commun Heat Mass Transf 39:541–550

    Article  Google Scholar 

  24. Schlichting H (1968) Boundary layer theory. McGraw Hill, New York

    MATH  Google Scholar 

  25. Nachtsheim PR, Swigert P (1965) Satisfaction of the asymptotic boundary conditions in numerical solution of the system of non-linear equations of boundary layer type. NASA TND-3004

  26. Alam MS, Rahman MM, Samad MA (2006) Numerical study of the combined free-forced convection and mass transfer flow past a vertical porous plate in a porous medium with heat generation and thermal diffusion. Non-linear Anal: Model Control 11:331–343

    MATH  Google Scholar 

  27. Kelson N, Desseaux A (2000) Note on porous rotating disk flow. ANZIAM J 42(E):C837–C855

    Article  MathSciNet  MATH  Google Scholar 

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Alam, M.S., Hossain, S.M.C. & Rahman, M.M. Effects of temperature dependent fluid properties and variable Prandtl number on the transient convective flow due to a porous rotating disk. Meccanica 49, 2439–2451 (2014). https://doi.org/10.1007/s11012-014-9995-9

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  • DOI: https://doi.org/10.1007/s11012-014-9995-9

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