Heat Transfer Enhancement for Internal Flows with a Centrally Located Circular Obstruction and the Impact of Buoyancy

Abstract

Numerical simulations have been carried out for gas flow through a horizontal pipe. Accounting is made of buoyancy effects, changes to the thermophysical properties, and the presence of a blockage. It was found that for low-to-moderate Reynolds numbers, the combined effects on heat transfer and pressure loss lead to an improved performance with the obstruction. On the other hand, the influence of heating on properties is shown to have a significant effect on the Nusselt number in both the laminar and the turbulent regions. Property variations increase the laminar Nusselt number and decrease the turbulent values. The results also show that a blockage has a much bigger impact on laminar flows than on turbulent flows and can inhibit downstream buoyant motion and convective heat transfer.

Acknowledgments

The authors would like to gratefully acknowledge Birla Institute of Technology and Science, Pilani, Pilani Campus for their funding (research grant – Additional Competitive Research Grant) and University of St Thomas, School of Engineering in this research.

Conflict of  interest statement

No potential conflict of interest was reported by the authors.

Table 4b. Uniform heating 2000 W/m², with blockage.

Additional information

Funding

This work was supported by Birla Institute of Technology and Science, Pilani, Pilani Campus and University of St Thomas, School of Engineering.

Notes on contributors

Lauren Olsen

Lauren Olsen is a thermal scientist specializing in aerospace applications and fundamental drag and heat transfer performance. She completed her MS degree in Mechanical Engineering from the University of St. Thomas and she currently works in the aerospace industry as a scientist where she studies aerodynamics and aerospace instrumentation. She employees both experimental and computational tools to solve problems related to airborne sensors. She recently published a major study on blunt-body convective correlations and has presented her work at major professional conferences.

Suvanjan Bhattacharyya

Suvanjan Bhattacharyya is an Assistant Professor at the Birla Institute of Technology & Science, Pilani, at Pilani campus where he teaches and performs research in thermal sciences. Previously, he completed his PhD at Jadavpur University and then completed a post-doctoral position at the University of Pretoria, with Dr. Josua Meyer. His research interests encompass the study of laminar and turbulent fluid flow in both steady and unsteady situations. He has authored more than 90 papers and is on the editorial board of 11 journals and has served as a reviewer for more than 50 journals. He is also very active in service to the community; he orchestrates numerous publications and conference organizations.

Lijing Cheng

Lijing Cheng is a Professor at the Institute of Atmospheric Physics, in Beijing, China where he studies heat flow in large and small environments. Previously, he completed his PhD at the Institute of Atmospheric Physics, Chinese Academy of Sciences. He utilizes analytical and computational tools to study thermal transport and his work spans from the human scale to the global scale. He has won numerous research awards and is currently studying the simultaneous influence of temperature and salinity in determining buoyant flows. He recently was awarded the WCRP/GCOS International Data Prize 2020 for his work on developing and disseminating datasets associated with heat transfer in the oceans. His research has been covered by the Guardian, CNN, CBS News, NBC News, ABC News, and other news outlets. He has produced approximately 85 publications.

Wally Minkowycz

W. J. “Wally” Minkowycz is a Professor at the University of Illinois at Chicago where he teaches and carries out research in the thermal sciences. Over the past five decades, he has won numerous teaching and research awards and his research has spanned computational heat transfer, two-phase swirling flow, heat and mass transport in porous media, non-Newtonian flows, and turbulence in homogeneous flows and porous media. He developed the Sparrow-Galerkin approach to radiant heat exchange. He has served as editor for International Journal of Heat and Mass Transfer, International Communications in Heat and Mass Transfer, and Numerical Heat Transfer. He has more than 100 journal papers that have in excess of 10 citations, and over 300 publications in total. He has made deep and lasting impacts on many students, both undergraduate and graduate, over his many-decade career.

John Abraham

John Abraham is a Professor at the University of St. Thomas where he carries out research in thermal sciences. He has published approximately 350 works including journal papers, books, book chapters, conference presentations, and patents. His work includes laminar-intermittent-transitional flow, computational fluid dynamics, buoyant flows, modeling of flow in large-scale systems, and mass transport. He is currently a coeditor of the Advances in Heat Transfer and he recently helped found a company that pasteurizes water in the developing world to alleviate water-borne illness, the second most common cause of death for children under 5 years of age.