Skip to main content
Log in

Conjugate natural convection between horizontal eccentric cylinders

  • Original
  • Published:
Heat and Mass Transfer Aims and scope Submit manuscript

Abstract

This study involved the numerical investigation of conjugate natural convection between two horizontal eccentric cylinders. Both cylinders were considered to be isothermal with only the inner cylinder having a finite wall thickness. The momentum and energy equations were discretized using finite volume method and solved by employing SIMPLER algorithm. Numerical results were presented for various solid–fluid conductivity ratios (KR) and various values of eccentricities in different thickness of inner cylinder wall and also for different angular positions of inner cylinder. From the results, it was observed that in an eccentric case, and for KR < 10, an increase in thickness of inner cylinder wall resulted in a decrease in the average equivalent conductivity coefficient (\(\overline{{K_{eq} }}\)); however, a KR > 10 value caused an increase in \(\overline{{K_{eq} }}\). It was also concluded that in any angular position of inner cylinder, the value of \(\overline{{K_{eq} }}\) increased with increase in the eccentricity.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10
Fig. 11
Fig. 12

Similar content being viewed by others

Abbreviations

a :

Location of the positive pole of the bipolar coordinate system on the y-axis, r o sinhη o

D :

Dimensionless parameter, 2(r o  − r ii )

e :

The distance between centers of two cylinders (m)

E :

Dimensionless eccentricity, e/(r o  − r oi )

E 1 :

Dimensionless eccentricity, e/(r o  − r ii )

F :

Bouancy force or convective mass flux at face of control volume

g :

Gravitational accelaration (ms−2)

h :

Coordinate transformation scale factor

i :

Index of the numerical grid in ξ and φ directions

k :

Auxiliary index for averaging properties of interface nodes

H :

Dimensionless coordinate transformation factor, h/D

KR :

Solid–fluid conductivity ratio (Ks/Kf)

K eq :

Local equivalent conductivity coefficient

\(\overline{{K_{eq} }}\) :

Average equivalent conductivity coefficient

L :

r o  − r oi

L* :

r o  − r ii

N :

Annulus radius ratio, r oi /r o

n :

Number of bipolar grid nodes in η-direction

p :

Pressure of fluid (Pa)

P :

Dimensionless pressure of fluid

q :

Number of cylindrical grid nodes in r-direction

r o :

Radius of outer cylinder (m)

r ii :

Inner radius of inner cylinder (m)

r oi :

Outer radius of inner cylinder (m)

r′:

Distance from the center of the inner cylinder to the outer cylinder (m)

R :

Dimensionless component of cylindrical coordinate, R = r/r ii

R* :

Dimensionless distance in radii direction

RR :

Radius ratio of outer cylinder to inner cylinder, r o /r ii

S φ :

Source term

T :

Temprature at any point (K)

w :

Velocity in ξ direction (ms−1)

v :

Velocity in η direction (ms−1)

u ref :

Reference velocity (ms−1)

V :

Dimensionless η-velocity component

W :

Dimensionless ξ-velocity component

Ra :

Rayleigh number

Pr:

Prandtl number

α :

Thermal diffusivity of fluid or the angle measured from top with the origin of Cartesian coordinate

β :

Volumetric coefficient of thermal expansion

Γ:

Diffusion coefficient

η :

The first transverse bipolar coordinate

η i :

Value of η on the outer surface of inner cylinder, Cosh−1[(N(1 + E 2) + 1 − E 2)/(2 N·E)]

η o :

Value of η on the surface of outer cylinder, Cosh−1[(N(1 − E 2) + 1 + E 2)/(2E)]

θ :

Dimensionless temperature

μ :

Dynamic viscosity of fluid (N s m−2)

ν :

Kinematic viscosity (m2 s−1)

ξ :

The second transverse bipolar coordinate

ρ :

Fluid density (kg m−3)

φ:

The azimuth angle in cylindrical coordinate

ψ:

Stream function

c :

Cold

f :

Fluid

h :

Hot

i :

Inner

o :

Outer

s :

Solid

N, E :

Evaluated in north and east of control volume, respectively

W, S :

Evaluated in west and south of control volume, respectively

References

  1. Shu C, Yao Q, Yeo KS, Zhu YD (2002) Numerical analysis of flow and thermal fields in arbitrary eccentric annulus by differential quadrature method. J Heat Mass Transf 38:597–608

    Article  Google Scholar 

  2. Bubnovich VI, Kolesnikov PM (1986) Conjugate transient heat transfer in laminar natural convection in a horizontal cylindrical annulus. J Eng Phys 19:1175–1181

    Article  Google Scholar 

  3. Rotem Zeev (1972) Conjugate free convection from horizontal conducting circular cylinders. Int J Heat Mass Transf 15:1679–1693

    Article  MATH  Google Scholar 

  4. Kolesnikov PM, Bubnovich VE (1988) Non-stationary free-convective heat transfer in horizontal cylindrical coaxial channels. Int Heat Mass Transf 31(6):1149–1156

    Article  MATH  Google Scholar 

  5. Liu Y, Phan-Thien RKemp (1996) Coupled conduction–convection problem for a cylinder in an enclosure. Comput Mech 18:429–443

    Article  MATH  Google Scholar 

  6. Sambamurthy NB, Shaija A, Narasimham GSVL, Krishna Murthy MV (2008) Laminar conjugate natural convection in horizontal annuli. Int J Heat Fluid Flow 29:1347–1359

    Article  Google Scholar 

  7. El-Shaarawi MAI, Mokheimer EMA, Jamal A (2005) Conjugate effects on steady laminar natural convection heat transfer in vertical eccentric annuli. Int J Comput Methods Eng Sci Mech 6(4):235–250

    Article  MATH  Google Scholar 

  8. Perlmutter M, Howell JR (1963) Radiant transfer through a gray gas between concentric cylinders using Monte Carlo. Trans ASME J Heat Transf 39:169–179

    Google Scholar 

  9. Onyegegbu SO (1986) Heat transfer inside a horizontal cylindrical annulus in the presence of thermal radiation and buoyancy. Int J Heat Mass Transf 29(5):659–671

    Article  MATH  Google Scholar 

  10. Shaija A, Narasimham GSVL (2009) Effect of surface radiation on conjugate natural convection in a horizontal annulus driven by inner heat generating solid cylinder. Int J Heat Mass Transf 52:5759–5769

    Article  MATH  Google Scholar 

  11. Fattahi E, Farhadi M, Sedighi K (2011) Lattice Boltzmann simulation of mixed convection heat transfer in eccentric annulus. J Int Commun Heat Mass Transf 38(8):1135–1136

    Article  Google Scholar 

  12. Maudou L, Choueiri GH, Tavoularis S (2013) An experimental study of mixed convection in vertical, open-ended, concentric and eccentric annular channels. J Heat Transf 135(7):072502–072509

    Article  Google Scholar 

  13. Hughes and Gaylord (1964) Basic equations of engineering science. MacGraw-Hill, NewYork

    Google Scholar 

  14. Versteegh HK, Malalasekera W (1995) An introduction to computational fluid dynamics: the finite volume method. Longman Scientific & Technical, England

    Google Scholar 

  15. Lewis PE, Ward JP (1989) Vector analysis for engineering and science. Addison Wesley, Boston

    Google Scholar 

  16. Dehghan AA, Khoshab M (2010) Numerical simulation of buoyancy-induced turbulent flow between two concentric isothermal spheres. Heat Transf Eng 31(1):33–44

    Article  Google Scholar 

  17. Kuehn TH, Goldstein RJ (1978) An experimental study of natural convection heat transfer in concentric and eccentric horizontal cylindrical annuli. J Heat Transf 100:635–640

    Article  Google Scholar 

  18. Shu C, Wu YL (2002) Domain-free discretization method for doubly connected domain and its application to simulate natural convection in eccentric annuli. Comput Methods Appl Mech Eng 191:1827–1841

    Article  MATH  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Ali Akbar Dehghan.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Nasiri, D., Dehghan, A.A. & Hadian, M.R. Conjugate natural convection between horizontal eccentric cylinders. Heat Mass Transfer 53, 799–811 (2017). https://doi.org/10.1007/s00231-016-1862-x

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s00231-016-1862-x

Keywords

Navigation