Natural Convection Heat Transfer Around Heated Cylinders Inside a Cavity With Conducting Walls

A numerical study has been conducted for natural convection heat transfer for air around two vertically separated horizontal heated cylinders placed inside a rectangular enclosure having finite wall conductances. The interaction between convection in the fluid-filled cavity and conduction in the walls surrounding the cavity is investigated. Results have been obtained for Rayleigh numbers Ra between 10 3 I. Tokura , H. Saito , K. Kishinami , and K. Muramoto , An Experimental Study of Free Convection Heat Transfer from a Horizontal Cylinder in a Vertical Arcay Set in Free Space between Parallel Walls , J. Heat Transfer , vol. 105 , pp. 102 – 107 , 1993 .[Crossref] , [Google Scholar] and 10 6 M. Lacroix , Natural Convection Heat Transfer around Two Heated Horizontal Cylinders inside a Rectangular Cavity Cooled from Above , Numer. Heat Transfer Part A , vol. 21 , pp. 37 – 54 , 1992 .[Taylor & Francis Online], [Web of Science ®] , [Google Scholar], dimensionless wall-fluid thermal conductivity ratio α between 0.2 and 1000.0, and different thermal boundary conditions. The results indicate that wall heat conduction reduces the average temperature differences across the cavity, partially stabilizes the flow, and decreases natural convection heat transfer around the cylinders. Heat removal through the vertical wall is significant even when its outer surface is insulated. The overall heat transfer coefficient for both cylinders is correlated with C Ran for different α and thermal boundary conditions.