GFDI Seminar: Dr. Jinzi Mac Huang
Sculpting of a dissolvable body through natural and forced solutal convection
Dr. Jinzi Mac Huang
New York University
Dissolution in fluids leads to the occurrence of many natural pattern formations. For example the Karst topography occurs when water dissolves limestone, and travertine terraces form as a balance of dissolution and precipitation. Dissolution, ablation and erosion are related problems involving the close interaction of a fluid domain and the solid morphology. Unlike erosion, dissolution can happen with or without external flow through molecular diffusion. The dissolved solute causes convection and leads to a self-generated flow, which enhances the dissolution and changes the shape dynamics. In our study, we consider the shape evolution of a soluble object immersed in water, both with external flow imposed and in quiescent fluid. We find that different conditions lead to one of three possible outcomes during the shape evolution. In one case, the shape maintains a memory of its initial form, which is preserved throughout the entire dissolving process. A second possibility is that the shape converges to a unique final shape, which persists thereafter before vanishing. And the last possibility is a ‘runaway process’ in which that the shape continues to evolve throughout time without reaching any terminal stage. These different possibilities affect our ability to accurately infer past conditions from observations of the present morphology, an issue of general importance in geomorphology.