Granular collapse on particle-laden water
Phys. Rev. Fluids 11, 024803 – Published 12 February, 2026
DOI: https://doi.org/10.1103/hcyb-7nhz
Abstract
We investigate the generation and propagation of an impulse wave on a particle-laden water bath produced by the subaerial collapse of a granular column. Laboratory experiments were performed by releasing dense granular columns into water covered with a monolayer of buoyant particles. By systematically varying column height, water depth, and particle size, we explored the role of the buoyant particles on wave type and characteristics, and made direct comparisons with waves on a particle-free interface. The coupled particle–wave dynamics were found to markedly reshape both the waveform and the particle distribution. Buoyant particles delayed the transition from nonbreaking to breaking waves, with the magnitude of the delay increasing with particle size. After wave generation, two distinct particle-accumulation regions emerged: a static buildup adjacent to the collapsed grains that buttressed the pile, and a dynamic concentration zone traveling with the wave front that acted to suppress breaking. Despite these differences from the particle-free case, the maximum wave amplitude was found to primarily correlate with the geometry of the collapsed column, enabling the use of a simple model to relate the wave amplitude and initial column configuration. These results suggest that a buoyant surface layer modulates wave generation and propagation, providing potential insights into impulse waves triggered by glacier calving in proglacial fjords laden with ice mélange.
