Settling of inertial nonspherical particles in wavy flow

Rising and Sinking in Resonance: Mass Distribution Critically Affects Buoyancy-Driven Spheres via Rotational Dynamics

“…Clearly, such an offset can also be expected to occur in a host of practical applications, where particle properties are rarely ever uniform. This concerns, for example, the falling of dandelion seeds [30] and snowflakes [31][32][33][34][35], the sedimentation behavior of sand grains and stones [36,37], chemical and biological reactors with (inverse) fluidized beds [38], as well as the transport of microplastic in the oceans [39]. Moreover, the practical relevance is rooted in the fact that we find that even small values of γ can affect the kinematics and dynamics of spherical particles significantly.…”

Enhanced settling and dispersion of inertial particles in surface waves

“…Finally, we compare our theoretical results with the experimental data of settling spheres under surface waves reported in Clark et al (2020), where we have conducted a re-analysis of the previously reported data. The experiments investigated spheres with diameter 2.96 mm settling in three different wave conditions in water of depth 41.5 cm: a = 3.5 cm, ω = 2π rad s −1 ('shallow'; ka = 0.15, kh = 1.78), a = 3.3 cm, ω = 3π rad s −1 ('intermediate'; ka = 0.29, kh = 3.7) and a = 2.3 cm, ω = 4π rad s −1 ('deep'; ka = 0.32, kh = 5.9).…”

“…The data were originally reported in terms of an ensemble mean of the instantaneous particle vertical velocities as a function of a dimensionless 'velocity scale reflective of the local vertical flow velocities' and the results appear to show an increase with this quantity (see their figure 3). This analysis allowed Clark et al (2020) to combine data across wave conditions, scaled by relative wave strength. To compare with our drift predictions, we average the instantaneous vertical velocities of the particles in a similar way, but now as a function of both wave conditions and dimensionless depth.…”

“…Laboratory experiments have similarly measured enhanced settling (Clark et al 2020;De Leo et al 2021), although these experiments have been outside the regime of the low particle Reynolds number assumed in theoretical works, making it difficult to perform a direct comparison. Additionally, non-spherical particles have been shown to experience an angular analogue to Stokes drift that causes particles to adopt preferred orientations (DiBenedetto & Ouellette 2018; DiBenedetto, Koseff & Ouellette 2019) that alter their trajectories in shape-dependent ways (DiBenedetto, Ouellette & Koseff 2018;Clark et al 2020). The combined findings of these studies show the value of analysing particle dynamics from a Stokes drift framework.…”

Wake induced dynamics of buoyancy-driven and anisotropic particles

“…This concerns e.g. the falling of dandelion seeds [6] and snowflakes [44][45][46][47][48], the sedimentation behaviour of sand grains and stones [49,50], chemical and biological reactors with (inverse) fluidized beds [51], as well as the transport of micro-plastic in the oceans [52]. The practical relevance is moreover rooted in the fact that we find that even small values of W can a ect the kinematics and dynamics of spherical particles significantly.…”