Numerical Investigation of Nucleate Pool Boiling Heat Transfer for Different Superheat Conditions

Abstract

Nucleate boiling has been a topic of great interest due to its heat transfer enhancement capability. In the present work, a highly resolved numerical model is developed combining two submodels, a microlayer evaporation submodel and phase change sub model, to get insights on various sub-processes like bubble inception, growth, departure, waiting time and scavenging effect. Here, a new approach in contact angle modeling is implemented by using a variable contact angle which is pre-defined using curve-fitting of the experimental data with respect to bubble cycle time. For the performance evaluation of the model, two fluids, water and a refrigerant (HFE7100) under two superheat conditions are studied and results are validated with existing experimental data. The simulations are carried out to understand the individual contribution of microlayer and other sub-processes toward overall heat transfer and such individual contributions are rare in the available literature. It was concluded that microlayer heat transfer is the second most important contributing component of heat transfer for both superheat conditions and contributes ∼30% for both the fluids. Moreover, the influence of superheat over bubble dynamics is analyzed. Overall, the comparison of present simulation with existing test data indicates a satisfactory agreement.

Acknowledgments

The work was supported by Cummins Technology India Ltd., India. Authors acknowledge the support received from Cummins Technology India Ltd.

Conflict of interest

The authors declare that there is no conflict of interest.

Additional information

Notes on contributors

Palakkeel Irinavu Shyamkumar

Palakkeel Irinavu Shyamkumar is a PhD student at the Indian Institute of Technology Bombay, India, under the supervision of Prof. Suneet Singh and Prof. Atul Srivastava. He received his bachelor's degree in 2008 from Govt. College of Engineering Kannur, India, and master's degree in 2011 from Indian Institute of Technology Guwahati, India. He also serves as an employee of Cummins Technology India Limited, as a Technical Specialist in CFD domain. His research interests involve the numerical modeling of nucleate pool and flow boiling heat transfer, investigation of microlayer phenomena, and cooling system design and development.

Suneet Singh

Suneet Singh is currently working as Professor in the Department of Energy Science and Engineering at IIT Bombay. Before joining IIT Bombay he was a post-doctoral fellow at Idaho National Lab, USA. He did his Bachelor of Engineering from Maulana Azad College of Technology (now MANIT). He has master’s and PhD degrees in Nuclear Engineering from IIT Kanpur and University of Illinois, respectively. His areas of research include solar thermal, nuclear reactor thermal-hydraulics; and advanced numerical methods for fluid flow and neutron diffusion. He has been awarded Bhaskara Advanced Solar Energy (BASE) fellowship in year 2014 from Indo-US Science and Technology Forum. He was guest editor for special issue on nuclear reactor stability published in Progress in Nuclear Energy.

Atul Srivastava

Atul Srivastava is currently working as Professor in the Department of Mechanical Engineering, IIT Bombay, India. Prior to joining IIT Bombay, he worked as a Scientist at Raja Ramanna Center for Advanced Technology, Indore, India. His research interests include development and applications of laser-based optical imaging techniques for investigating transport phenomena in fluid flow and heat transfer applications, biomedical applications of lasers and crystal growth. He has been the recipient of several national and international awards like the prestigious Swarna Jayanti Fellowship by DST, India, JSPS fellowship, Dr. K.S. Krishnan Research fellowship awarded by Government of India. He was awarded the best doctoral thesis award by Indian National Academy of Engineering and Indian Laser Association in the year 2007.

Milan Visaria

Milan Visaria holds the PhD degree and MS degree from mechanical engineering department, Purdue University West Lafayette, IN. His PhD research involved the development of a new class of heat exchangers for the storage of hydrogen in automobiles. His MS work involved the study of two-phase spray cooling for electronics applications at the Boiling and Two-Phase Flow Laboratory, Purdue University, West Lafayette, Indiana, USA. He also serves as an employee of Cummins Technology India Limited, as a System Performance Lead in IC engine domain. His research interests involve the two-phase flow boiling heat transfer in electronic cooling systems, and hydrogen storage and engine system performance.