The Effect of Holes Number in Cylindrical Samples on the Forced Convection Heat Flow

In this article, an experimental examine changed into carried out on the effect of putting side holes in circular cylinders on the forced convection heat transfer process. Three circular cylindrical samples were made of aluminum. Sample No.1 without side holes, sample No.2 with two side holes, and sample No.3 with four side holes. These cylindrical samples were placed after being heated in an air duct (working section) and the position of samples in an air duct are same. Air cross-flow was applied to the cylindrical samples at different velocities while observing their temperature drop.  The results showed that heat transfer of the cylindrical sample with four side holes is better than that of other samples at all air flow velocities. Also Nusselt number was calculated after obtained heat transfer coefficient and at Reynolds number range (7435-20697), where it become discovered that Nusselt number will increase with the Reynolds number in all cylindrical samples. Empirical relationships for Nusselt number with Reynolds number and Prandtl number had been get it for the three circular cylinders and liken with relationships of circular cylindrical forms exist in other references. These Empirical relationships given acceptable constants values.