CFD study on the heat transfer in vertical rifled tube with different helical angles

.A.Hawig , Abdurauf.A (2011) CFD study on the heat transfer in vertical rifled tube with different helical angles. Masters thesis, Universiti Tun Hussein Onn Malaysia.

[img]
Preview
PDF
1192Kb

Abstract

In this research, computational fluid dynamics (CFD) study of heat transfer and fluid flow monitoring of vertical rifled tubes with two different helical angles (30o and 45o) has been carried out. The rifled tube has an outer diameter of 25mm, maximum inner diameter of 18.8 mm; minimum inner diameter of 17.50mm, rib width of 9.25, and the number of starts is four. The CFD simulation were conducted on a vertical orientation of the steel rifled tube under six different inlet velocities; 0.893, 1.765, 2.38, 2.897, 3.57, 4.166 m/s. The fluid used is water and the initial temperature is 298K. The objective of this study is to determine the heat transfer and drop pressure of rifled tubes with helical angles (30o and 45o) compared with rifled tube result at 60o helical angles. The results of rifled tube with 30 o helical angle show higher temperature for lower inlet velocity. The temperature difference between the inlet and outlet of the tube is equal to 10.19 K for inlet velocity of 0.893 m/s. For inlet velocity of 4.166 m/s on the other hand, the temperature different is 2K. Similar patterns are found for results of rifled tube with 45o helical angle. In addition, comparison of results for 30oand 45o rifled tubes to rifled tube with 60o helical angle yield only slight deviation. The pressure drop of the tubes with 30oand 45o helical angles at higher inlet velocity is 17277.2 Kpa and 19426.44Kpa, respectively. While for both tubes at low inlet velocity, there are equal to 1295.9 Kpa, 1444.088Kpa, respectively. The results show lower pressure drop in the rifled tube for lower inlet velocity. Comparison of results shows that the pressure drops for 30o and 45o helical angle always higher than the 60o helical angle for all cases. Consequently, it can be concluded that the increase in the helical angle for the rifled tube gives no effect on heat transfer but it does in drop pressure.

Item Type:Thesis (Masters)
Subjects:Q Science > QC Physics
ID Code:1722
Deposited By:Normajihan Abd. Rahman
Deposited On:28 Sep 2011 13:06
Last Modified:28 Sep 2011 13:06

Repository Staff Only: item control page