We investigate the three-dimensional melting dynamics of an initially spherical particle translating in a warmer liquid using sharp-interface simulations that fully resolve both solid and fluid phases with the Stefan condition. A wide parameter space is explored, spanning initial Reynolds number (Re₀), Stefan number (St), and Richardson number (Ri). In the absence of buoyancy (Ri= 0), the interface evolution is governed by canonical wake bifurcations. Four regimes are identified: an axi-symmetric regime (Re₀355) with fluctuating stagnation points and a more rounded rear. Despite these differences, all regimes exhibit a tendency toward melt-rate homogenisation over time. Besides, we introduce an aspect-ratio-based surface-area formulation that yields a predictive model, accurately capturing volume evolution across regimes. Hydrodynamic loads also reflect the coupling between shape and flow: drag follows rigid-sphere correlations only at moderate Re₀; planar rears enhance drag at higher Re₀; lift appears only in symmetry-broken regimes and reverses late in time; torque reorients the rear plane toward vertical, consistent with free-body experiments. When buoyancy is included, assisting configurations (Ri>0) suppress recirculation and maintain quasi-spherical shapes, whereas opposing or transverse buoyancy (Ri<0) destabilises wakes and promotes tilted planar rears. These results provide a unified framework for convection-driven melting across laminar, periodic, and chaotic wakes, with implications for geophysical and industrial processes.
Xue et al. (Thu,) studied this question.