Diffusion-limited settling of highly porous particles in density-stratified fluids.

ABSTRACT: The vertical transport of solid material in a stratified medium is fundamental to a number of environmental applications, with implications for the carbon cycle and nutrient transport in marine ecosystems. In this work, we study the diffusion-limited settling of highly porous particles in a density-stratified fluid through a combination of experiment, analysis, and numerical simulation. By delineating and appealing to the diffusion-limited regime wherein buoyancy effects due to mass adaptation dominate hydrodynamic drag, we derive a simple expression for the steady settling velocity of a sphere as a function of the density, size, and diffusivity of the solid, as well as the density gradient of the background fluid. In this regime, smaller particles settle faster, in contrast with most conv

SUBMITTER: Hunt R 

PROVIDER: S-EPMC12207462 | biostudies-literature | 2025 Jun

REPOSITORIES: biostudies-literature