fabricated which consists of three copper tubes of diameter 41.2 mm, 25.35 mm and 12.6
mm and the length of the tubes are 580 mm, 740 mm and 857 mm, respectively. The
thickness of the outer, middle and inner tubes are 1.25 mm, 0.94 mm and 0.80 mm,
respectively. The objective of this study is to reduce the length and material cost as well as
increase the heat transfer surface area by adding an intermediate tube to the double …