Influence of Broken Twisted Tape on Heat Transfer Performance in Novel Axial Corrugated Tubes: Experimental and Numerical Study

Abstract

The insertion of a broken twisted tape (BTT) in tube is a novel passive heat transfer augmentation method, which constitutes the subject of the present investigation. Effect of BTT on heat transfer performance in novel triangular axial corrugated tubes is investigated experimentally and numerically. In order to augment the thermohydraulic performance, a corrugated tube with inserts is offered. The analyses are conducted for Reynolds number extending from 10,000 to 80,000 within the turbulent regime. The shear stress transport model is applied as the turbulence model. Air is used as the working fluid. The typical full-length twisted tapes with two different twist ratios and the broken twisted tape with two different twist ratios, and three gap ratios are used for the comparative analysis. The angular pitch between the two neighboring corrugations and the angle of the corrugation are kept constant through the experiments at 120^° and 60^°, respectively, while three different corrugations heights are analyzed. Eventually, correlations for predicting friction factor and Nusselt number are developed. The thermohydraulic performance is also calculated. The results show a good correspondence with the measurements and the published correlations of other researchers. For all examined cases, the performance factors are always larger than unity.

Disclosure statement

No conflict of interest was reported by the authors.

Acknowledgments

The authors would like to gratefully acknowledge University of Pretoria, BITS Pilani, MCKVIE, and Sam Casting for their support in this research.

Additional information

Notes on contributors

Suvanjan Bhattacharyya

Suvanjan Bhattacharyya is currently working as an Assistant Professor in the Department of Mechanical Engineering of Birla Institute of Technology and Science Pilani, Pilani Campus, Rajasthan, India. He completed his post-doctoral research in Department of Mechanical and Aeronautical Engineering from University of Pretoria, South Africa. His research interest lies in CFD in fluid flow and heat transfer, specializing on laminar, turbulent, steady, unsteady separated flows and convective heat transfer, experimental heat transfer enhancement. He is the author and coauthor of 85 papers in high-ranked journals and prestigious conference proceedings with an H-index of 15. He has bagged Best Paper Award in a number of international conferences as well. He is also on editorial boards of 11 international journals and reviewer of more than 25 prestigious journals.

Ali Cemal Benim

Ali Cemal Benim received his BSc and MSc in Mechanical Engineering from the Bosphorus University of Istanbul, Turkey, and PhD degree from the University of Stuttgart, Germany, in1988. Following his postdoctoral period at the University of Stuttgart, he joined ABB Turbo Systems Ltd. in Baden, Switzerland, in 1990. He was the Manager of the Computational Flow and Combustion Modeling group. Since 1996, he is a Professor for Flow Simulation and Energy Technology at the Düsseldorf University of Applied Sciences, Germany.

Rachid Bennacer

Rachid Bennacer is an engineer in mechanical field and received his PhD degree at Pierre et Marie Curie University (Paris 6) in 1993. He worked as lecturer in the University Paris XI (1993/94), became an associate professor at Cergy Pontoise University in 1994, and full professor in 2008. He moved as senior professor to the prestigious school Ecole Normale Superieure (Paris-Saclay) in 2010. He becomes an Exceptional National Class Professor since 2017. He is also adjunct professor at Tianjin Uni. Of comm. (China) and EPMI/Paris Ing. School. His present research activity is within the LMT laboratory where he manages Transfer and Environmental Research Unit. His research field covers the building material for energy applications or on durability aspect, renewable and energy system, direct numerical simulation including CFD coupling on multi-scales. He has published around 10 book chapters and more than 150 referenced international journals (Rank A).

Kunal Dey

Kunal Dey is an undergraduate final-year mechanical engineering student of MCKV Institute of Engineering, India. His research interest lies in experimental heat transfer, computational fluid dynamics, and air-conditioning and refrigeration. He has received Best Paper Award in many national and international conferences.