Natural-Convection Phenomenon from a Finned Heated Vertical Tube: Experimental Analysis
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.
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.
Copyright: Open Access authors retain the copyrights of their papers, and all open access articles are distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution and reproduction in any medium, provided that the original work is properly cited. The use of general descriptive names, trade names, trademarks, and so forth in this publication, even if not specifically identified, does not imply that these names are not protected by the relevant laws and regulations. While the advice and information in this journal are believed to be true and accurate on the date of its going to press, neither the authors, the editors, nor the publisher can accept any legal responsibility for any errors or omissions that may be made. The publisher makes no warranty, express or implied, with respect to the material contained herein.