An Enhanced Volume of Fluid Based Numerical Modelling Approach for Sub-Micron Scale Boiling Heat Transfer: Proceedings of the ASME 2024 7th International Conference on Micro/Nanoscale Heat and Mass Transfer

To explore the complicated physics of boiling heat transfer, researchers are increasingly using numerical simulation methods like the Volume of Fluid (VOF) and the Diffuse Interface (DI) approaches. The VOF method, popular for macro-scale simulations (μm to mm), effectively tracks the bubble growth and detachment. On the other hand, the DI method, which represents the interface as a continuous phase field, is mainly used for mesoscale simulations (nm to μm). The DI method is precise in resolving microscopic interfacial phenomena, but is computationally expensive for larger domains. Based on the pros and cons of the VOF and DI methods, a multi-scale modeling approach that combines the strengths of both can be utilised in the future. To pursue the goal, an initial attempt is taken to check the scaling capability of VOF in lower spatial and temporal limits. Therefore, an enhanced customised VOF methodology that has been developed within the OpenFOAM tool-box is employed here for various bubble growth scenarios exploring its applicability at progressively lower temporal and spatial scales, scaling down traditional application scales with a factor of 10 and 100, aiming to identify the resulting accuracy. It is shown for the first time, that the enhanced VOF model can accurately and effectively simulate phase-change and boiling behaviour at sub-micron scales that have not been explored in the past.