Non-monotonic Ice-core Thawing in Water Pool Leading by Flow Competition

Numerical simulations reveal that this anomaly arises from competing convective mechanisms driven by the density-temperature anomaly at ~4°C of water. The sides come from the anomaly chaotic flow induced by boundary-core thermal gradients, and the normal natural convection stabilized by buoyancy from the density extremum near the core.

As the pool temperature increases from 2.5 to 80 °C, the flow transitions from a chaotic to a steady state. Within the transitional regime, however, flow stability decreases with the Fourier number, eventually can leading to re‑chaotization. The pool size modulates the competition between chaotic flow and natural convection through the Rayleigh numbers, which govern both the extreme points in thawing time and the extent of the non‑monotonic effect, thereby enabling precise control over thawing kinetics.