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Three-dimensional optimization of staggered finned circular and elliptic tubes in forced convection

Publication ,  Journal Article
Matos, RS; Laursen, TA; Vargas, JVC; Bejan, A
Published in: International Journal of Thermal Sciences
May 1, 2004

This paper presents a three-dimensional numerical and experimental geometric optimization study to maximize the total heat transfer rate between a bundle of finned tubes in a given volume and external flow, for staggered arrangements of circular and elliptic tubes. Experimental results were obtained for circular and elliptic configurations with twelve tubes, starting with an equilateral triangle configuration, which fitted uniformly into the fixed volume with a resulting optimal dimensionless tube-to-tube spacing of S/2b=1.5, where S is the actual spacing and b is the smaller semi-axis of the ellipse. Several experimental configurations were built by reducing the tube-to-tube spacings, identifying the optimal spacing for maximum heat transfer. Similarly, it was possible to investigate the existence of optima with respect to two other geometric degrees of freedom, such as tube eccentricity and fin-to-fin spacing. The results are reported for air as the external fluid in the laminar regime, for ReL=852 and 1065, where L is the swept length of the fixed volume. Circular and elliptic arrangements with the same flow obstruction cross-sectional area were compared on the basis of maximizing the total heat transfer. This criterion allows one to isolate and quantify the heat transfer gain, by studying arrangements with equivalent total pressure drops independently of the tube cross-section shape. This paper continues with three-dimensional numerical optimization results for finned circular and elliptic tubes arrangements, which are validated by direct comparison with experimental measurements. Global optima with respect to tube-to-tube spacing, eccentricity and fin-to-fin spacing (S/2b≅0.5, e≅0.5, φf≅0.06 for ReL=852 and 1065) were found and reported in dimensionless terms. A relative heat transfer gain of up to 19% is observed in the optimal elliptic arrangement, as compared to the optimal circular one. The heat transfer gain, combined with the relative material mass reduction of up to 32% observed in the optimal elliptic arrangement in comparison to the circular, show that the elliptical tubes arrangement has better overall performance and lower cost than the traditional circular tubes geometry. © 2003 Elsevier SAS. All rights reserved.

Duke Scholars

Published In

International Journal of Thermal Sciences

DOI

ISSN

1290-0729

Publication Date

May 1, 2004

Volume

43

Issue

5

Start / End Page

477 / 487

Related Subject Headings

  • Mechanical Engineering & Transports
  • 4017 Mechanical engineering
  • 4012 Fluid mechanics and thermal engineering
  • 0915 Interdisciplinary Engineering
  • 0913 Mechanical Engineering
  • 0102 Applied Mathematics
 

Citation

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ICMJE
MLA
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Matos, R. S., Laursen, T. A., Vargas, J. V. C., & Bejan, A. (2004). Three-dimensional optimization of staggered finned circular and elliptic tubes in forced convection. International Journal of Thermal Sciences, 43(5), 477–487. https://doi.org/10.1016/j.ijthermalsci.2003.10.003
Matos, R. S., T. A. Laursen, J. V. C. Vargas, and A. Bejan. “Three-dimensional optimization of staggered finned circular and elliptic tubes in forced convection.” International Journal of Thermal Sciences 43, no. 5 (May 1, 2004): 477–87. https://doi.org/10.1016/j.ijthermalsci.2003.10.003.
Matos RS, Laursen TA, Vargas JVC, Bejan A. Three-dimensional optimization of staggered finned circular and elliptic tubes in forced convection. International Journal of Thermal Sciences. 2004 May 1;43(5):477–87.
Matos, R. S., et al. “Three-dimensional optimization of staggered finned circular and elliptic tubes in forced convection.” International Journal of Thermal Sciences, vol. 43, no. 5, May 2004, pp. 477–87. Scopus, doi:10.1016/j.ijthermalsci.2003.10.003.
Matos RS, Laursen TA, Vargas JVC, Bejan A. Three-dimensional optimization of staggered finned circular and elliptic tubes in forced convection. International Journal of Thermal Sciences. 2004 May 1;43(5):477–487.
Journal cover image

Published In

International Journal of Thermal Sciences

DOI

ISSN

1290-0729

Publication Date

May 1, 2004

Volume

43

Issue

5

Start / End Page

477 / 487

Related Subject Headings

  • Mechanical Engineering & Transports
  • 4017 Mechanical engineering
  • 4012 Fluid mechanics and thermal engineering
  • 0915 Interdisciplinary Engineering
  • 0913 Mechanical Engineering
  • 0102 Applied Mathematics