In this work, the onset of heterogeneous bubble nucleation is studied using molecular dynamics (MD) simulations. In classical theory of nucleation, it is well established that, there exists an energy barrier corresponding to critical radius of bubble, and a minimum energy is required to overcome this barrier for bubble growth. Therefore, it is important to estimate and predict the critical radius of nucleation for which bubble grows over time. Although homogenous nucleation is studied through experiments and theoretical models, heterogeneous nucleation poses significant challenges due to the complexity of liquid-surface interaction. For such study at nanoscale MD simulation is a viable tool, but existing published MD work on heterogeneous nucleation on superheated walls have not characterized nucleation behavior and its origins, partially because of unavailability of a verified surface-fluid heating algorithm in transient phase. Therefore a heating model was first implemented and its transient behavior was verified using LAMMPS. With the help of this model, a heterogeneous bubble in liquid argon is generated by partially heating the platinum surface to different temperatures. These simulation results in either a collapsing, stable or growing bubble for which Gibbs free energy is estimated and compared. The change in behavior of these bubbles represents an existence of a critical radius of nucleation. Based on these simulations, a heat transfer based analytical model is developed to predict the critical width required for bubble nucleation at the nanoscale.


A Molecular Dynamics Study of Onset Heterogeneous Bubble on Super-Heated Surface

Division / Sponsors: 
Heat Transfer Division (HTD), Fluids Engineering Division (FED)

Heat Transfer Summer Conference
Paper Proceedings: https://asmedigitalcollection.asme.org/HT/HT2020/volume/83709

18th International Conference on Nanochannels, Microchannels, and Minichannels
Paper Proceedings: https://asmedigitalcollection.asme.org/ICNMM/ICNMM2020/volume/83693

Fluids Engineering Division Summer Meeting
Paper Proceedings: https://asmedigitalcollection.asme.org/FEDSM/FEDSM2020/volume/83716

HT-ICNMM2020 - Virtual Conference, SHTC - Virtual Conference, FEDSM2020 - Virtual Conference

Supporting the need among researchers worldwide for additional online and multimedia content, ASME now offers the ASME Conference Video Collection. This platform will collect and provide long-term access to conference presentation videos, encompassing all technology areas within ASME's technical conference and events program. About 30,000-40,000 engineers across all mechanical engineering and related disciplines participate in ASME conferences each year. This includes authors of approximately 6,000 to 8,000 technical papers published by ASME, the majority of whom also submit video presentations for our virtual conferences. The video collection will be available as an add-on to existing product packages or as a separate subscription.