Skip to main content
SpringerLink
Log in

An experimental investigation on performance of annular fins on a horizontal cylinder in free convection heat transfer

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

Abstract.

Natural convection heat transfer in annular fin-arrays mounted on a horizontal cylinder was experimentally investigated. An experimental set-up was constructed to investigate heat transfer characteristics of 18 sets of annular fin-arrays mounted on a horizontal cylinder of 24.9-mm diameter in atmospheric conditions. Keeping the fin thickness fixed at 1 mm, fin diameter is varied from 35 mm to 125 mm and fin spacing is varied from 3.6 mm to 31.7 mm. The base-to-ambient temperature difference was also varied with a calibrated wattmeter ranging from 25 W to 150 W. The results have shown that the convection heat transfer rate from the fin arrays depends on fin diameter, fin spacing and base-to-ambient temperature difference. In addition, for every fin diameter, for a given base-to-ambient temperature difference, there exists an optimum value for the fin spacing for which the heat transfer rate from the fin array is maximised. Experimental results show that, for practical engineering applications, the optimum fin spacing may be taken approximately as 8 mm. A scale analysis is also performed in order to estimate order-of-magnitude of optimum fin spacing at a given fin diameter and base-to-ambient temperature difference. The correlation obtained from scale analysis is the result of limited number of experiments. This correlation may be generalised by applying the order-of-magnitude analysis developed in this work for wider range of experiments.

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

Access this article

Log in via an institution

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

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1.
Fig. 2.
Fig. 3.
Fig. 4.
Fig. 5.
Fig. 6.
Fig. 7.
Fig. 8.
Fig. 9.
Fig. 10.
Fig. 11.
Fig. 12.
Fig. 13.
Fig. 14.
Fig. 15.
Fig. 16.
Fig. 17.
Fig. 18.
Fig. 19.
Fig. 20.
Fig. 21.
Fig. 22.
Fig. 23.

Similar content being viewed by others

Abbreviations

A :

Area, m2

C p :

Specific heat at constant pressure, kJ/(kg · K)

d :

Outer diameter of the horizontal cylinder, m

d i :

Inner diameter of the horizontal cylinder, m

D :

Fin diameter, m

E b :

Blackbody radiosity, W/m2

F ji :

View factor

g :

Gravitational acceleration, m/s2

Gr :

Grashof number

h :

Convection heat transfer coefficient, W/(m2 · K)

h exp :

Experimental convection heat transfer coefficient of horizontal cylinder, W/(m2 · K)

I :

Input current to heater, A

J :

Radiosity, W/m2

k :

Thermal conductivity, W/(m · K)

L :

Length of the horizontal cylinder, m

ṁ :

Mass flow rate, kg/s

N :

Number of fins

Nu :

Nusselt number

Pr :

Prandtl number

Q̇ :

Power input to the heater, W

Q̇ c :

Convection heat transfer rate, W

Q̇ c (1) :

Convection heat transfer rate from fins in small-s limit, W

Q̇ c (2) :

Convection heat transfer rate from fins in large-s limit, W

Q̇ r :

Radiation heat transfer rate, W

Q̇ 0 :

Total heat transfer rate from the horizontal cylinder, W

(Q̇ 0) c :

Convection heat transfer rate from the horizontal cylinder, W

(Q̇ 0) r :

Radiation heat transfer rate from the horizontal cylinder, W

Q̇ r,i :

Net radiation heat transfer from surfaces, W

Ra :

Rayleigh number

s :

Fin spacing, m

t :

Fin thickness, m

T a :

Ambient temperature, K

T f :

Film temperature, K

T w :

Wall temperature, K

V :

Input voltage to the heater, V

α:

Thermal diffusivity, m2/s

β:

Volumetric thermal expansion coefficient, 1/K

ɛ:

Emissivity

ν:

Kinematic viscosity, m2/s

σ:

Stefan-Boltzmann constant, W/(m2 · K4)

ΔT :

Base-to-ambient temperature difference, K

References

  1. Kraus AD (1965) Cooling electronic equipment, Prentice-Hall, New Jersey

  2. Kern DQ; Kraus AD (1972) Extended surface heat transfer, McGraw-Hill, New York

  3. Kakaç S, et al (1994) Cooling of electronic systems. NATO ASI Series, Kluwer Academic Publishers, Dordrecht

  4. Starner KE; McManus HN (1963) An experimental investigation of free convection heat transfer from rectangular fin arrays. J Heat Transfer 273–278

  5. Welling JR; Wooldridge CB (1965) Free convection heat transfer coefficients from vertical fins. J Heat Transfer 439–444

  6. Harahap F; McManus HN (1967) Natural convection heat transfer from horizontal rectangular fin arrays. J Heat Transfer 32–38

  7. Jones CD; Smith LF (1970) Optimum arrangement of rectangular fins on horizontal surfaces for free convection heat transfer. J Heat Transfer 6–10

  8. Fitzroy ND (1971) Optimum spacing of fins cooled by free convection. J Heat Transfer 462–463

  9. Sparrow EM; Bahrami PA (1980) Experiments on natural convection heat transfer on the fins of a finned horizontal tube. Int J Heat Mass Transfer 1555–1560

  10. Sparrow EM; Niethammer JE (1981) Effect of vertical separation distance and cylinder-to-cylinder temperature imbalance on natural convection for a pair of horizontal cylinders. Trans ASME 638–643

  11. Leung CW, et al (1985) Heat exchanger design: thermal performances of rectangular fins protruding from vertical or horizontal rectangular bases. Appl Energy 123–140

  12. Kadle DS; Sparrow EM (1986) Numerical and experimental study of turbulent heat transfer and fluid flow in longitudinal fin arrays. J Heat Transfer 16–23

  13. Leung CW; Probert SD (1989) Thermal effectiveness of short-protrusion rectangular, heat-exchanger fins. Appl Energy 1–8

  14. Sobhan CB, et al (1990) Experimental studies on steady free convection heat transfer from fins and fin arrays. Warme Stoffübertragung 345–352

    Google Scholar 

  15. Yüncü H; Anbar G (1998) An experimental investigation on performance of rectangular fins on a horizontal base in free convection heat transfer. Heat Mass Transfer 507–514

  16. Yüncü H; Güvenç A (2001) An experimental investigation on performance of rectangular fins on a vertical base in free convection heat transfer. Heat Mass Transfer 409–416

  17. Incropera FP; DeWitt DP (1985) Fundamentals of Heat and Mass Transfer, John Wiley & Sons, New York

  18. Churchill SW; Chu HHS (1975) Correlating equations for laminar and turbulent free convection from horizontal cylinder. Int J Heat Mass Transfer 18: 1049–1053

    Google Scholar 

  19. Morgan VT (1975) The overall convective heat transfer from smooth circular cylinder. In: Irvine TF, Harnett JP (eds) Advances in Heat Transfer, Vol.11, 199–264, Academic Press, New York

  20. Naraghi MHN; Chung BTF (1982) Radiation configuration factors between disks and a class of axisymmetric bodies. Trans ASME 426–431

  21. Bejan A (1984) Convection Heat Transfer, John Wiley & Sons, New York

Download references

Author information

Authors and Affiliations

  1. Middle East Technical University, Department of Mechanical Engineering, 06531 Ankara, Turkey

    Ş. Yildiz & H. Yüncü

Authors
  1. Ş. Yildiz
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. H. Yüncü
    View author publications

    You can also search for this author in PubMed Google Scholar

Rights and permissions

Reprints and permissions

About this article

Cite this article

Yildiz, Ş., Yüncü, H. An experimental investigation on performance of annular fins on a horizontal cylinder in free convection heat transfer. Heat and Mass Transfer 40, 239–251 (2004). https://doi.org/10.1007/s00231-002-0404-x

Download citation

  • Received:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s00231-002-0404-x

Keywords

Search

Navigation