International Journal of Thermal Sciences 156 (2020) 106433 Available online 4 May 2020 1290-0729/© 2020 Elsevier Masson SAS. All rights reserved. Development of non-dimensional two phase heat transfer correlation based on physics of boiling Rajiva Lochan Mohanty a, b, ** , Mihir Kumar Das a a School of Mechanical Sciences, Indian Institute of Technology Bhubaneswar, Arugul, Odisha, 752050, India b School of Mechanical Engineering, Kalinga Institute of Industrial Technology, Bhubaneswar, Odisha, 751024, India A R T I C L E INFO Keywords: Nucleate boiling heat transfer coeffcient Bubble departure diameter Bubble departure frequency Active nucleation site density Buckingham π theorem ABSTRACT The present paper discusses a new approach for predicting the nucleate boiling transfer coeffcient based on the physics of nucleate boiling at atmospheric pressure under saturated conditions. Therefore, a non-dimensional correlation of the nucleate boiling heat transfer coeffcient developed as a function of bubble departure diam- eter, active nucleation site density, and bubble departure frequency. A non-dimensional correlation using non- dimensional numbers such as Bond number (Bo), Prandtl number (Pr), Capillary number (Ca), and Jakob number (Ja) is proposed to predict nucleate boiling heat transfer coeffcient. The Buckingham π-theorem is used to develop these non-dimensional numbers. The developed non-dimensional correlation of the bubble departure diameter (Bo) and frequency (Ca*) found to predict the present and experimental data of other investigator within an error of �12% and �15%, respectively. The non-dimensional nucleate boiling heat transfer coeffcient (Nu) correlation based on the non-dimensional numbers found to predict own and other experimental data within an error of �15%. The result shows the interdependency of bubble dynamic parameters to predict the nucleate boiling heat transfer coeffcient. 1. Introduction The necessity of high heat transfer rate within limited space of advanced heat dissipating equipment and instruments of modern era is the major challenge of the present research community. However, the two-phase heat transfer phenomenon seems to be a solution to this problem. The existing plethora of literature clearly shows that two- phase heat transfer phenomena can result in signifcant enhancement of the heat transfer rate for a given size of the heat-exchanging device. In other words, for a given heat transfer, the size of heat exchanging de- vices can be reduced. The materials worth several billions of rupees can save when used in the fabrication of heat exchanging equipment utilized in thermal power plants, nuclear power plants, chemical process plants, and other alike industries. Therefore, accurate prediction of the two- phase heat transfer coeffcient is essential as it directly affects the cost, weight, and size of the heat exchanging equipment. The physics of nucleate boiling is entirely different from any other two-phases or single-phase heat transfer process due to its complex nature. Its complexity is due to the nucleation, growth, and detachment of vapor bubbles of a given liquid over the heated surface. Thus, the vapor bubble is the media through the latent heat carried away from the heated surface and dissipated to the free surface of the liquid. In other words, the information of the vapor bubble from its initiation to grow to de- parture along with the number of sites from which it initiates and also the number of the vapor bubble departs from the corresponding sites on the heated surface signifcantly affects the physics of nucleate boiling. Therefore, the state-of-art of this phenomenon is that the bubble dy- namic parameters such as bubble departure diameter, bubble departure frequency, and active nucleation site density regulated the nucleate boiling heat transfer. So, the accurate predictions of these parameters are crucial for precise prediction of the nucleate boiling heat transfer coeffcient. Many empirical, semi-empirical correlations for prediction of nucleate boiling heat transfer coeffcient are available in the literature. However, almost all these correlations predict their experimental results reasonably but unable to predict the experimental data of other in- vestigators [1]. Besides, there are a few correlations, which use bubble dynamic parameters to predict the nucleate boiling heat transfer coef- fcient, as shown in Table 1. From this Table, it can be seen that both non-dimensional (Eqs. (1)– (6)) and dimensional (Eq. (7)) correlations are proposed to predict the nucleate boiling heat transfer coeffcient. However, the non-dimensional * Corresponding author. School of Mechanical Sciences, Indian Institute of Technology Bhubaneswar, Argul, Odisha, 752050, India. E-mail addresses: rajivamohanty@gmail.com, rm20@iitbbs.ac.in (R.L. Mohanty), mihirdas@iitbbs.ac.in (M.K. Das). Contents lists available at ScienceDirect International Journal of Thermal Sciences journal homepage: http://www.elsevier.com/locate/ijts https://doi.org/10.1016/j.ijthermalsci.2020.106433 Received 12 April 2019; Received in revised form 17 April 2020; Accepted 17 April 2020