Effects of Contact Angle Hysteresis on Nucleate Boiling Bubble Dynamics and Heat Transfer

In this work, we employ a high-fidelity numerical model that integrates microlayer evaporation and contact angle hysteresis to systematically investigate the influence of contact angle hysteresis on bubble dynamics and heat transfer during nucleate boiling. The model is rigorously validated against both analytical solutions and experimental data, showing very good agreement. Notably, comparison with experimental results demonstrates that it not only successfully predicts bubble dynamics, but also accurately captures the transient and local heat transfer characteristics on the heating surface. We explore the evolutions of bubble dynamics, temperature field, wall temperature/heat flux distribution, and microlayer distribution beneath the bubble with high temporal and spatial resolutions. Our results reveal a strong interdependence between bubble dynamics and nucleate boiling heat transfer. Contact angle hysteresis is shown to directly modulate contact line motion, thereby governing microlayer evolution and dictating heat transfer characteristics during nucleate boiling. We provide a quantitative assessment of the contribution of microlayer evaporation to bubble heat transfer. This work highlights the significant role of contact angle hysteresis in nucleate boiling simulations and offers comprehensive insights into its effects on phase change heat transfer processes.