Freezing Interface Stabilization by Obstacle-Guided Convection and Concentration Segregation

Description

Interfacial instability fundamentally limits designable multicomponent solidification separation by causing uncontrolled solute entrapment. A multiphysics model with a novel solute exclusion potential is proposed to investigate the obstacle-guided freeze desalination. Parameter studies show that separating low and high concentration regions can expand the pure ice layer by reducing interfacial instability. The introduce of fixed obstacles reorganizes heat and solute transport to create stable regions for pure ice growth and continuous brine rejection. A solute‑retention zone forms upstream of each obstacle, while the downstream sheltering region lowers the local concentration gradient and suppresses interfacial instability. Mullins-Sekerka analysis reveals that this geometry shifts the interface toward a stable regime, while convection determines whether rejected brine remains connected or fragments into trapped pockets. The resulting obstacle-guided strategy provides a passive geometric strategy for suppressing interfacial instability during solidification, broadly applicable to separation processes where solute entrapment limits performance.

Institutions

• Tsinghua University

  Beijing, Beijing

Categories

Licence