Chahboub was born in 1981 in Constantine,

Copyright © 2011 Praise Worthy Prize S.r.l. - All rights reserved International Review of Mechanical Engineering, Vol. 5, N. 2 Special Issue on Heat Transfer 368 Flow in Uniformly Heated Horizontal Tubes, ASHRAE Trans., 95, Part 1, 1989, 171-178. [4] T. Boufendi et al, The Physical Aspect of Three-Dimensional Mixed Convection in a Uniformly Heated Horizontal Pipe, Sciences Technologie A, 22, 2004, 39-52. [5] P. H. Newell Jr. et al, Analysis of Combined Free and Forced Convection for Fully Developed Laminar Flow in Horizontal Tubes, ASME J. Heat Transfer, 92, 1970, 83-93. [6] J. W. Baughn, Effect of Circumferential Wall Heat Conduction on Boundary Conditions for Heat Transfer in a Circular Tube, ASME J. Heat Transfer, 100, 1978, 537-539. [7] M. Ouzzane et al, Effets de la Conduction Pariétale et de la Répartition du Flux Thermique sur la Convection Mixte près de l’Entrée d’une Conduite Inclinée, Int. J. Thermal Sciences, 38, 1999, 622-633. [8] M. Ouzzane et al, Developing Mixed Convection in an Inclined Tube with Circumferentially Nonuniform Heating at its Outer Surface, Num. Heat Transfer, Part A, 35, 1999, 609-628. [9] B. Shome et al, Mixed Convection Laminar Flow and Heat Transfer of Liquids in Isothermal Horizontal Circular Ducts. Int. J. Heat Mass Transfer, 38, 1995, 1945-1956. [10] B. Shome, Effect of Uncertainties in Fluid Properties on Mixed Convection Laminar Flow and Heat transfer in a Uniformly Heated Smooth Tube, Num. Heat Transfer, Part A, 35, 1999, 875-889. [11] T. Boufendi et al, Three-dimensional Conjugate Conduction- Mixed Convection with Variable Fluid Properties in a Heated Horizontal Pipe, Rev. Energies Renouvelables, 8, 2005, 1-18. [12] C. Abid et al, Etude de la Convection Mixte dans un Conduit Cylindrique. Approche Analytique Numérique et Détermination Expérimentale de la Température de Paroi par Thermographie Infrarouge, Int. J. Heat Mass Transfer, 37, 1994, 91-101. [13] S. W. Churchill et al, Correlating Equation for Laminar and Turbulent Free Convection from a Horizontal Cylinder. Int. J. Heat Mass Transfer, 18, 1975, 1049-1053. [14] H. D. Baehr et al, Heat and Mass Transfer, Springer-Verlag, Berlin, 1998. [15] S. V. Patankar, Numerical Heat Transfer and Fluid Flow, McGraw-Hill, New-York, 1980. Authors’ information Energetic Physics Laboratory LPE. Faculty of Sciences. Mentouri University, Constantine. 25000 Constantine, Algeria.

K. Chahboub was born in 1981 in Constantine,

Algeria. He received the Graduate degree in Energetic Physics in 2008 from the university Mentouri. Currently, he is preparing the Magister degree in Energetic Physic. Dr T. Boufendi was born in 1958 in Constantine, Algeria. He received his Doctorat Degree in 2005 from the Mentouri University of Constantine UMC. His main interest of research concerns the computational heat transfer and fluid dynamic, in particular the internal flows with conjugate heat transfer conduction, forced and mixed convection in pipe. Actually, he is a teacher – Associate Professeur- and he is a head of research team at the laboratory of Energetic Physics LPE of the UMC. Special Issue on Heat Transfer, February 2011 Manuscript received and revised January 2011, accepted February 2011 Copyright © 2011 Praise Worthy Prize S.r.l. - All rights reserved 369 Experimental Investigation of Elliptical Cross Section Geometry Wickless Heat Pipe Charged with Distilled Water and Ethanol Ajit M. Kate, Ratnakar R. Kulkarni Abstract – An experimental investigation was performed in order to observe the effect of the inclination angle and working fluid fill charge on the transport behaviour of a wickless heat pipe. Wickless heat pipe with elliptical cross section geometry was designed and manufactured. Distilled water and ethanol were used as a working fluid in each elliptical cross section geometry wickless heat pipe. The experiments were carried out at different electric heat input and the inclination angle β towards the vertical position. The experimental results indicate that the temperature distribution along the wall surface of ethanol-charged pipe was higher than water- charged wickless heat pipe. The effect of working fluid water, ethanol has significant effect on heat transfer characteristics of wickless heat pipe. Copyright © 2011 Praise Worthy Prize S.r.l. - All rights reserved. Keywords: Wickless Heat Pipe, Inclination Angle, Heat Transfer Coefficient, Elliptical Cross Section Nomenclature C Specific heat kJkg K D Diameter m D h Hydraulic diameter m h Heat transfer coefficient Wm 2 C I Current A ID Inside diameter of tube m L Length of tube m m Mass flow rate kgs OD Outside diameter of tube m q Heat flux kWm 2 T Temperature C V Voltage V Greek Symbol β Inclination angle Subscripts c Condenser e Evaporator av Average in Inlet of cooling water out Outlet of cooling water v Vapor W Water

I. Introduction