Skip to main content
SpringerLink
Log in

Numerical Study of Flow Over Annular Elliptical Finned Tube Heat Exchangers

  • Research Article - Mechanical Engineering
  • Published:
Arabian Journal for Science and Engineering Aims and scope Submit manuscript

Abstract

In the present study, performance of a tube row with annular elliptical fin was compared to the circular type. It was shown that heat transfer coefficient and pressure drop are functions of ratio of horizontal diameter to vertical diameter. It means that not only the diameter ratio, but also ellipse orientation affects heat transfer and pressure drop. Interestingly, it was found out that the pressure drop may be as low as one half of a circular fin tube. Moreover, with the same incoming air velocity, heat transfer coefficient on vertical fin is higher than circular type. Because of the lower pressure drop, higher incoming velocity may be applied, and therefore, higher heat transfer can be achieved. Altogether, tube with annular elliptical fin may be a good candidate for circular type when there is space restriction or severe limitation on pressure drop.

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

Similar content being viewed by others

Abbreviations

A = A f + A t :

Total fin tube area per unit length of fin tube

A f :

Fin surface area per unit length of fin tube

A t :

Tube surface area per unit length of fin tube

Eu :

Euler number

Ḣ :

Air flow rate enthalpy

Nu :

Nusselt number

P :

Pressure

Q̇ :

Heat exchange between fin tube and air

T in :

Air inlet temperature

T out :

Air outlet temperature

T w :

Tube wall temperature

U in :

Air inlet velocity

d :

Tube outside diameter

h :

Air side heat transfer coefficient

k :

Air thermal conductivity

k f :

Fin thermal conductivity

L 1 :

Larger fin length

L 2 :

Smaller fin length

n :

Number of tube rows, n = 1]]

p :

Tube pitch, 63.5 mm

q :

Heat exchange between fin tube and air per unit air mass flow rate

r 1 :

Larger fin radius

r 2 :

Smaller fin radius

r h :

Horizontal fin radius

r v :

Vertical fin radius

s :

Fin spacing

t f :

Fin thickness

u max :

Maximum air velocity in tube bundle

\({\Delta P}\) :

Air pressure drop in bundle

\({\eta}\) :

Fin efficiency

\({\theta}\) :

Log mean temperature difference

\({\mu}\) :

Air viscosity

\({\rho}\) :

Air density

References

  1. Shah R.K., Sekulic D.P.: Fundamentals of Heat Exchanger Design. Wiley, New York (2003)

    Book  Google Scholar 

  2. Xi, G.N.; Torikoshi, K.: Computation and visualization of flow and heat transfer in finned tube heat exchangers. In: International Symposium on Heat Transfer. Tsinghua University, Beijing, China, (7.10–11.10), pp. 632–637 (1996)

  3. Nemati H., Moghimi M.: Numerical study of flow over annular-finned tube heat exchangers by different turbulent models. CFD Lett. 6, 101–111 (2014)

    Google Scholar 

  4. Petracci I., Manni L., Gori F.: Numerical simulation of the optimal spacing for a radial finned tube cooled by a rectangular jet. I—Average thermal results. Int. J. Therm. Sci. 104, 54–67 (2016)

    Article  Google Scholar 

  5. Moore J.A., Stevenson J.P.J., Grimes R.: Thermal and flow characteristics of a single-row circular-finned tube heat exchanger under elevated free-stream turbulence. Int. J. Heat Fluid Flow 57, 48–57 (2016)

    Article  Google Scholar 

  6. Jnana R.S., Sukanta K.D., Subhranshu R.: Numerical investigation of natural convection heat transfer over annular finned horizontal cylinder. Int. J. Heat Mass Transf. 96, 330–345 (2016)

    Article  Google Scholar 

  7. Jang J.Y., Lei J.T., Liu L.C.: The thermal-hydraulic characteristics of staggered annular finned-tube heat exchangers under dry and dehumidifying conditions. Int. J. Heat Mass Transf. 41, 3321–3337 (1998)

    Article  Google Scholar 

  8. Mon M.S., Gross U.: Numerical study of fin-spacing effects in annular-finned tube heat exchangers. Int. J. Heat Mass Transf. 47, 1953–1964 (2004)

    Article  Google Scholar 

  9. Nagarani N., Mayilsamy K.: Experimental heat transfer analysis on annular circular and elliptical fins. Int. J. Eng. Sci. Technol. 2, 2839–2845 (2010)

    Google Scholar 

  10. Nagarani N., Mayilsamy K., Murugesan A.: Fin effectiveness optimization of elliptical annular fins by genetic algorithm. Proced. Eng. 38, 2939–2948 (2012)

    Article  Google Scholar 

  11. Kundu B., Das P.K: Performance analysis and optimization of elliptic fins circumscribing a circular tube. Int. J. Heat Mass Transf. 50, 173–180 (2007)

    Article  MATH  Google Scholar 

  12. Nemati H., Samivand S.: Simple correlation to evaluate efficiency of annular elliptical fin circumscribing circular tube. Arab. J. Sci. Eng. 39, 9181–9186 (2014)

    Article  Google Scholar 

  13. Nemati H., Samivand S.: Performance optimization of annular elliptical fin based on thermo-geometric parameters. Alex. Eng. J. 54(4), 1037–1042 (2015)

    Article  Google Scholar 

  14. Jacobi A.M., Shah R.K.: Air-side flow and heat transfer in compact heat exchangers: a discussion of enhancement mechanisms. Heat Transf. Eng. 19(4), 29–41 (1998)

    Article  Google Scholar 

  15. FLUENT User Guide

  16. Smith E.C., Gunter A.Y., Victory S.P.J.R.: Fin tube performance. CEP 62(7), 57–67 (1966)

    Google Scholar 

  17. Briggs D.E., Young E.H.: Convection heat transfer and pressure drop of air flowing across triangular pitch banks of finned tubes. Chem. Eng. Prog. Symp. 59(41), 1–10 (1963)

    Google Scholar 

  18. Gianolio E., Cuti F.: Heat Transfer Coefficients and Pressure Drops for Air Coolers under Induced and Forced Draft. Heat Transf. Eng. 3(1), 38–48 (1981)

    Article  Google Scholar 

Download references

Author information

Authors and Affiliations

  1. Department of Mechanics, Marvdasht Branch, Islamic Azad University, Marvdasht, Iran

    H. Nemati

  2. Department of Mechanical Engineering, Aligoodarz Branch, Islamic Azad University, Aligoodarz, Iran

    S. Samivand

Authors
  1. H. Nemati
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. S. Samivand
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to H. Nemati.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Nemati, H., Samivand, S. Numerical Study of Flow Over Annular Elliptical Finned Tube Heat Exchangers. Arab J Sci Eng 41, 4625–4634 (2016). https://doi.org/10.1007/s13369-016-2226-z

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s13369-016-2226-z

Keywords

Search

Navigation