Numerically Modeling the Flow and Friction Within a Helically-Finned Tube

Abstract

As the populations and the economies of the world grow, the demand for electricity rises and necessitates an increase in the supply of electricity as the primary fuels that are used to generate electricity are finite and exhausting. Moreover, mounting concerns about carbon emissions and the current direction of environmental legislation are pushing for lower emissions and higher efficiencies of energy producing facilities. One approach to abate such dilemmas is to increase the efficiency of the modern steam cycle, which is used to generate most of the world's electricity. Improving the components of the steam cycle, or the boiler component in particular, can affect the overall efficiency of the steam cycle significantly. An integral constituent of the boiler is the boiler tube. There are several types of boiler tubes, and the helically-finned tube is one type that has proven to increase the efficiency of the boiler. However, insight to the internal flow within the helically-finned tube is still developing and incomplete. The objective of this study was to computationally model the internal flow and measure the friction factor of a helically-finned tube for which experimental data was already published. Using three different modeling techniques, the flow was solved numerically with Fluent, a computational fluid dynamics software package. With respect to the experimental data, the Fluent solutions reflected percent errors ranging between 14% and 27%. Although the results are acceptable, suggestions for future work are included.