Natural-Convection Phenomenon from a Finned Heated Vertical Tube: Experimental Analysis

  • Saad Najeeb Shehab Department of Mechanical Engineering / Engineering Faculty / Al-Mustansiriayah University
Keywords: Vertical tube, continuous, interrupted, finned, natural-convection.

Abstract

       In this work, an experimental analysis is made to predict the thermal performance of the natural-convection phenomenon from a heated vertical externally finned-tube to surrounding air through an open-ended enclosure. Two different configurations of longitudinal rectangular fin namely, continuous and interrupted are utilized with constant thickness, different numbers, and different heights are extended radially on the outer surface of a heated tube. The tube is heated electrically from inner surface with five varied power input magnitudes. The effect of fins configuration, fins number, fins height, and heat flux of the inner tube surface on the thermal performance of natural convection have been studied and analyzed experimentally. Obtained results show that the tube with twelve interrupted longitudinal fins gives the best natural-convection thermal performance in terms of average Nusselt number, about 20% greater than that for the tube with continuous fins. Experimental correlations to predict the average Nusselt number for the heated tubes with continuous and interrupted longitudinal fins are proposed. The present data are compared to previous study and good convergence is noticed.

Downloads

Download data is not yet available.

References

Morgan, V. T. “The Overall Convective Heat Transfer from Smooth Circular Cylinders”, Advances in Heat Transfer, Elsevier Ltd., Vol. 11, pp. 199-264, 1975.

Stewart, W. E. and Verhulst, J. L. “Experimental Free Convection from Piping in District Heating Utilidors”, Journal of Energy Resources Technology, ASME, 108 (2), PP. 173-178, 1986.

Wu, J. M. and Tao, W. Q. “Numerical Computation of Laminar Natural Convection Heat Transfer around a Horizontal Compound Tube with External Longitudinal Fins”, Journal of Heat Transfer Engineering, Vol. 28, Issue 2, pp. 93-102, 2007.

Kadhim, S. K. and Abdulhussain, K. “Experimental Study of Inclination Angle and Surface Area Effects for Longitudinally Finned Cylinder on Free Convection Heat Transfer in an Open Enclosure“ , Journal of Engineering and Technology, Vol. 27, No. 5, pp.171-179, 2009.

Dogan, A., Akkus, S. and Baskaya, S. “Numerical Analysis of Natural Convection Heat Transfer from Annular Fins on a Horizontal Cylinder“, Journal of Thermal Science and Technology, Vol. 32, No. 2, pp. 31-41, 2012.

Totala, B.T., Shimpi, M.V., Shete, N.L. and Bhopate, V.S. “Natural Convection Characteristics in Vertical Cylinder “ , International Journal of Engineering and Sciences, Vol. 3, Issue 8, pp. 27-31, 2013.

Niezgoda-Zelasko, B. And Zelasko, J. ”Free and Forced Convection on the Outer Surface of Vertical Longitudinally Finned Tubes”, Experimental Thermal and Fluid Science Journal, Elsevier Inc., Vol. 57 . pp. 145-156, September 2014.

Lee, J. B., Kim, H. J. and Kim, D. “Experimental Study of Natural Convection Cooling of Vertical Cylinders with Inclined plate Fins”, Energies Journal, 9, 391, pp. 1-15, 2016.

Cengel, Y. A. “Heat Transfer: A Practical Approach“, McGraw-Hill Companies, Second Edition, USA, 2008.

Favre-Marient, M. and Tardu, S. “Convective Heat Transfer“, John-Wiley and Sons, Inc., First Edition, USA, 2009.

Bejan, A.“Convection Heat Transfer“, John-Wiley and Sons Inc., Fourth Edition, USA, 2013.

Published
2019-03-20
How to Cite
Shehab, S. (2019). Natural-Convection Phenomenon from a Finned Heated Vertical Tube: Experimental Analysis. Al-Khwarizmi Engineering Journal, 13(4), 30- 40. https://doi.org/10.22153/kej.2017.05.004