fizyka: Upstream contamination

Evidence: 100 • authority: 72

Upstream contamination by floating particles is a counterintuitive phenomenon in fluid dynamics. When pouring water from a higher container to a lower one, particles floating in the latter can climb upstream into the upper container. A definitive explanation is still lacking: experimental and computational evidence indicates that the contamination is chiefly driven by surface tension gradients, however the phenomenon is also affected by the dynamics of swirling flows that remain to be fully investigated.

Evidence: 82 • authority: 92

Observation of upstream particle movement without the involvement of the marangoni effect.. Upstream Contamination is a counter-intuitive phenomena of fluid dynamics, where particles can go against the liquid stream and climb, higher containers. Previous studies have attributed the movement of particles against the flow of water to the Marangoni effect, where surface tension gradients drive fluid movement. However, the effect was not enough to account for the motion of particles. Meanwhile, this study challenges that explanation by documenting the ascent of fine particles of Iron Fillings, through a water jet where the lower container exhibited higher surface tension due to an aqueous calci…

Evidence: 42 • authority: 88

Water Vapour Adsorption Study in Spherical Particles Packed in a Cylindrical Container. In this work the water vapour adsorption was studied, during the initial states of absorption, for different piles of granules held in a cylindrical container. A diffusion model was presented for the description of the physical phenomenon whereby water vapour penetrates along the piles of cylindrical pores. The differential mass balance equation was solved numerically using a finite-difference method. The numerical solutions were tested through the measurement of water vapour mass uptake for different piles of silica gel and breakfast cereals (popcorns), being observed that they are in good agreement wit…

Evidence: 42 • authority: 92

Dynamics of internal bore migration within turbidity currents under variable dam slopes.. Reservoir sedimentation and turbidity currents present persistent challenges to water resources management by reducing storage capacity, degrading water quality, and increasing risks to hydraulic infrastructure. This study provides a spatiotemporal investigation of submerged muddy lake deformation, focusing on estimating the travel time of turbidity current head velocity between the plunge point and the dam. Such estimates are critical for optimizing sediment venting operations and mitigating sediment-related hazards. Additionally, the run-up height of forward-propagating turbidity currents and the dyn…