Hysteresis and Asymmetries in Transition Boiling

Boiling plays a critical role in various natural and industrial processes. Despite its ubiquity, accurately modeling boiling remains a significant challenge due to the broad range of spatial and temporal scales involved. In this study, we focus on transition boiling, an intermediate regime that occurs between nucleate boiling, where bubbles effectively transfer heat from the surface, and film boiling, where a vapor layer forms over the surface, insulating it and reducing heat transfer. This regime is inherently unstable and occurs near the boiling crisis, where the system approaches its maximum heat flux, leading to a sharp decline in heat removal efficiency. Transition boiling has critical implications for industrial cooling systems and nuclear reactor safety, as entering this regime can sharply reduce heat removal, potentially leading to overheating or component damage.

Employing GPU-accelerated Lattice Boltzmann simulations, we perform large-scale, high-resolution three-dimensional pool boiling simulations to investigate transition boiling with unprecedented detail. Our results show that transition boiling exhibits hysteresis, even under idealized conditions on smooth surfaces with constant temperature. Additionally, we observe distinct asymmetries in the transition process: while the heating branch leads to a sudden, memoryless shift to film boiling, the cooling branch shows a metastable coexistence of nucleate and film boiling states, which slows the recovery of efficient heat transfer.