The Stefan problem with mushy region as a scaling limit of stochastic PDE with turbulent transport
Ioana Ciotir, Franco Flandoli, Dan Goreac
TL;DR
This work analyzes the scaling limit of a stochastic Stefan problem with a mushy region under turbulent transport. By formulating the system through maximal monotone operators $ \Psi $ and $ g $, it shows that as the noise intensity sequence $\{\alpha^N\} $ satisfies $ \|\alpha^N\|_{l^{\infty}} \to 0 $, the law of the stochastic solutions $ X^N $ converges to the Dirac mass at the unique solution of the deterministic equation $ dX - \Delta\Psi(X)\,dt - \Delta g(X)\,dt = F X(0,\xi) = x $. The stochastic term vanishes in the limit, while the diffusion is augmented by $ -\Delta g(X) $, reflecting turbulence-enhanced melting. The proof uses energy estimates, tightness via compactness, and Skorokhod representation to identify the limit as the solution to the deterministic porous-media-type PDE, relying on the monotone-operator framework to ensure uniqueness. This provides a rigorous link between turbulent transport in phase-change problems and deterministic mushy-region evolution, with implications for ice-melting acceleration due to turbulence.
Abstract
This work establishes a scaling limit theorem for the Stefan problem incorporating a mushy region, demonstrating that solutions to stochastic variants with turbulent transport terms converge to the solution to a deterministic partial differential equation. The analysis builds upon recent advances in stochastic phase-change modeling and turbulent flow mathematics in [5]. In the physical interpretation of an ice melting process, our result shows that turbulence accelerates ice melting.
