Experimental study of natural convection heat transfer from vertical array of isothermal horizontal elliptic cylinders

Laminar free convection heat transfer from vertical array of horizontal isothermal elliptic cylinders with vertical major axis has been experimentalby investigated. Experiments were carried out using Mach-Zehnder interferometer with the cylinder spacing from two to five cylinder major axis and at Rayleigh numbers in the range between 10(3) and 2.5 x 10(3). The effects of cylinder spacing and Rayleigh number on the heat transfer from the individual cylinder and the array were investigated. It is found that the free convection heat transfer from any individual cylinder in the array depends on the Rayleigh number, cylinders separation distance and cylinder position in the array. Heat transfer correlations have been developed for both the individual cylinder in the array and the array. Also, a heat transfer correlation has been proposed for a single elliptic cylinder with vertical major axis and is compared with earlier works. (c) 2007 Elsevier Inc. All rights reserved.