Experimental study on Natural Convection heat transfer from an array of heated Cylinders located

Abstract

An experimental study on free convection heat transfer from a horizontal array consists of three cylinders heated under the condition of constant surface temperature was carried out. The study included clarifying the effect of separation distance between the cylinders and the distance that separate them from a floor, on the natural convection heat transfer from the array. The study showed that the ability of the cylinders to transmit heat with free convection is a function to separation distances between the cylinders also the distance between the cylinders and the floor, as well as Rayligh number, this ability is decrease too much when the separation distance from the floor and the neighborhood cylinder is small, the reduction in heat transfer for the center cylinder was (40%) in comparison with single cylinder test at vertical and horizontal separation distance of (1/8), the thermal performance for both cylinders may be got better as the separation distance increase, where the maximum enhancement in heat transfer for the center cylinder was recorded as (11%) in comparison with single cylinder test at vertical separation distance of (1) and horizontal separation distance of (3/4). The experimental results showed that the enhancement in heat transfer increases as the separation distance from the floor being larger, and the maximum heat transfer at small heights may be at high Rayligh numbers, where for high separation distances, the maximum relative enhancement may be observed at low Rayligh numbers.