Physics
Alcove formation in dissolving cliffs driven by density inversion instability
Document Type
Article
Abstract
We demonstrate conditions that give rise to cave-like features commonly found in dissolving cliffsides with a minimal two-phase physical model. Alcoves that are wider at the top and tapered at the bottom, with sharp-edged ceilings and sloping floors, are shown to develop on vertical solid surfaces dissolving in aqueous solvents. As evident from descending plumes, sufficiently large indentations evolve into alcoves as a result of the faster dissolution of the ceiling due to a solutal Rayleigh-Bénard density inversion instability. In contrast, defects of size below the boundary layer thickness set by the critical Rayleigh number smooth out, leading to stable planar interfaces. The ceiling recession rate and the alcove opening area evolution are shown to be given to first-order by the critical Rayleigh number. By tracking passive tracers in the fluid phase, we show that the alcoves are shaped by the detachment of the boundary layer flow and the appearance of a pinned vortex at the leading edge of the indentations. The attached boundary layer past the developing alcove is then found to lead to rounding of the other sides and the gradual sloping of the floor.
Publication Title
Physics of Fluids
Publication Date
5-2022
Volume
34
Issue
5
ISSN
1070-6631
DOI
10.1063/5.0092331
Keywords
amorphous materials, glass transitions, liquid solid interfaces, mass diffusivity, fluid mechanics, gravity currents, flow instabilities, boundary layer flow
Repository Citation
Sharma, Ram Sudhir; Berhanu, Michael; and Kudrolli, Arshad, "Alcove formation in dissolving cliffs driven by density inversion instability" (2022). Physics. 81.
https://commons.clarku.edu/faculty_physics/81
Cross Post Location
Student Publications
