Dynamics of elastic, nonheavy spheres sedimenting in a rectangular duct
Isabell Noichl1, Clarissa Schönecker1,2
1Technische Universität Kaiserslautern, D-67663 Kaiserslautern, Germany. schoenecker@mv.uni-kl.de.
Soft Matter
|March 13, 2022
Summary
Sedimentation dynamics of elastic spheres near walls differ from rigid spheres, showing a second acceleration phase. Softer spheres achieve higher terminal velocities, up to 9% greater than rigid ones.
Area of Science:
- Fluid dynamics
- Particle dynamics
- Rheology
Background:
- Sedimentation of rigid particles is well-understood.
- Sedimentation of elastic spheres in bounded fluids is not well-understood.
- Nonheavy spheres exhibit extended inertial effects.
Purpose of the Study:
- Investigate sedimentation dynamics of deformable, nonheavy spheres near walls.
- Compare elastic sphere sedimentation to rigid sphere behavior.
- Understand the influence of deformability on particle dynamics.
Main Methods:
- Model experiments using deformable, nonheavy spheres.
- Observation of sedimentation dynamics in the presence of walls.
- Analysis of particle acceleration and terminal velocity.
Main Results:
- Elastic spheres exhibit different dynamics compared to rigid spheres, even with small deformations.
- A characteristic onset position triggers deformability effects and a second acceleration.
- Terminal sedimentation velocity increases with decreasing sphere softness (Young's elastic modulus).
- Terminal velocities up to 9% higher than rigid spheres were observed.
Conclusions:
- Particle deformability fundamentally alters sedimentation dynamics in bounded fluids.
- Insights gained can inform models for elastic sphere dynamics.
- Deformable spheres can achieve higher terminal velocities than rigid counterparts.
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