Thermo-hydraulic performance investigation of a heat exchanger tube inserted with twisted tapes modified with various twist ratio and alternate axis

Authors : Mahmut UYANIK, Toygun DAĞDEVİR, Veysel OZCEYHAN

Pages : 189-195

Doi:10.26701/ems.1032081

View : 18 | Download : 7

Publication Date : 2022-09-20

Article Type : Research Paper

Abstract :This paper presents a numerical investigation on a heat transfer enhancement by using a computational fluid dynamics software. The heat transfer enhancement is implemented by inserting twisted tape into a heat exchanger tube. The twisted tapes with twist ratios of 4, 6 and 8 were modified with alternate axis. The pitch of the twisted tape having the rotation direction such as clockwise and counterclockwise are connected with 90º connection angle. Water is selected as working fluid and turbulent flow condition corresponding to Reynolds number ranging from 5000 to 29000 are considered in the study. The heat exchanger tube is under constant heat flux of 50 kW/m2. Numerical analysis results prove that the use of twisted tape improves thermal performance compared to smooth tube. As the twist ratio increased, the heat transfer performance and the friction loss penalty decreased. Overall results are determined with thermohydraulic performance criteria insert ignore into journalissuearticles values(THP);. The highest THP value is obtained as 1.21 for the tube inserted with the twisted tape which has the twist ratio of 4 and alternate axis between the twist pitches at Reynolds number of 5913
Keywords : Heat transfer enhancement, twisted tape, alternate axis, friction factor, performance evaluation criteria