Abstract
Heat transfer enhancement (HTE) efforts spent during the last half-century have become one of the most important working areas of researchers from both academia and industry. One of the most popular passive methods, with regard to the price-performance ratio, is to place wire coils in a pipe or duct. In this study, the heat and pressure drop characteristics of diamond, triangular, and circular cross-sectional wire coils (DWC, TWC, and CWC) in a square duct were investigated by using the FLUENT program. In addition to the cross-section examination, the thermo-hydraulic behavior of three different pitches (p = 54, 72, and 90 mm) for the specified geometries were also investigated. The Reynolds number was between 4387 and 18,415. The square duct was 1.25 m in length, and was 18 mm in diameter. The results showed that the Nusselt number of CWC, TWC, and DWC were higher than that of a smooth pipe within 38–88%, 37–93%, and 38–98% range, respectively. The friction of CWC, TWC, and DWC was observed to be higher than that of a plain tube within a range of 87–278%, 82–266%, and 107–366%, respectively. The TWC with 90 mm pitch showed the highest heat transfer performance evaluation criteria (PEC) with a performance coefficient of 1.3 at Reynolds number of 4504, whereas the DWC with 54 mm pitch was observed to show the lowest PEC. Thus, the as-obtained PEC, which is 30% higher than that of a plain tube, indicates the prominence and effectiveness of the numerical study in increasing the heat transfer.
Highlights
Heat exchangers are widely used in industry to cool or heat a system
In the 54 mm pitch study, the diamond type of wire coil (DWC)’s Nusselt number was higher than triangular cross-sectional wire coil (TWC) and cross-sectional wire coil (CWC) and the Nusselt number of TWC was higher than CWC
The Nusselt number of CWC, TWC, and DWC were higher than the smooth pipe in the range of 38–88%, 37–37%, and 38–98%, respectively
Summary
Heat exchangers are widely used in industry to cool or heat a system. The performance of heat exchangers has been improved with different enhancement techniques. One of the most popular and cost-effective technique is the passive technique This method uses either a wire coil (WC) installation or twisted tape-type elements in the pipe. Placing external elements in a heat exchanger system is the most common method used in passive technique. WCs are one of the popular passive methods and its effectiveness in the circular tube has been well researched in the literature In this context, many parameters of the installed WC are examined. Many parameters of the installed WC are examined Some of these parameters include the pitch ratio, the cross-section and geometry of the wire, and the use of different working fluids such as nanofluid types. Some of these parameters can be listed as follows: pitch ratio, cross-section, and variation of geometry, and the use of different fluids such as nanofluid
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
