Experimental & numerical investigation of heat transfer using twisted tapes with rectangular cuts

¹ Department of Mechanical Engineering, GRIET, Bachupally, Hyderabad, Telangana, India.
² JNTUH College of Engineering, Kukatpally, Hyderbad, Telangana, India.
³ KG Reddy College of Engineering and Technology, Hyderabad, Telangana, India
⁴ Department of Refrigeration and air Conditioning Techniques engineering, College of technical engineering, The Islamic University, Najaf, Iraq.

^* Corresponding Author: bulipechinanookaraju@gmail.com

Abstract

The current work focuses on using rectangular inserts with water as the working fluid to investigate heat transfer experimentally and numerically in a horizontal circular tube [10]. The study considers variations in the number of rectangular slots within the same strip. The tube has dimensions of 0.0266 m diameter. Twisted tapes, featuring rectangular cuts, are constructed from a 3 mm thick Stainless-steel strip with a length of 1035 mm. For experimentation, two different types of rectangular inserts were considered: one with nine cuts and the other with eighteen cuts. The dimensions of the cuts were as follows: length of 1000 mm, width of 13 mm, depth of cut 8 mm, and thickness 3 mm. The heat flux applied to the horizontal tube was steady and uniform. The range of the Reynolds number was 9,000–19,000. A plain tube without an insert was used to compare the results. The horizontal tube along with rectangular insert was modelled in Ansys Fluent software with fine meshing and analysed. Initially, CFD analysis was done for plain tube with and without insert, and results have been verified by comparison with experimental values. A comprehensive comparison is established, evaluating different heat transfer parameters, including convective heat transfer coefficient (h), heat transfer rate (q), and Nusselt number (Nu).