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Updated: Feb 20, 2026
08:49
Impacts of Free-falling Spheres on a Deep Liquid Pool with Altered Fluid and Impactor Surface Conditions
Published on: February 17, 2019
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Impacting spheres: from liquid drops to elastic beads.
Saumili Jana1, John Kolinski2, Detlef Lohse1,3
1Physics of Fluids Department, Max Planck Center Twente for Complex Fluid Dynamics, and J. M. Burgers Center for Fluid Dynamics, University of Twente, P.O. Box 217, 7500AE Enschede, The Netherlands. s.jana@utwente.nl.
Soft Matter
|February 18, 2026
Summary
This study unifies liquid and solid impact by exploring viscoelastic materials. It reveals how elasticity and relaxation time control impact forces, bridging classical liquid and solid theories.
Area of Science:
- Fluid dynamics
- Rheology
- Materials science
Background:
- Liquid drops spread, retract, and jump on impact.
- Elastic solids deform slightly and bounce.
- Impact forces are described by Wagner's (liquids) and Hertz's (solids) theories.
Purpose of the Study:
- To bridge the gap between liquid and solid impact theories using viscoelastic materials.
- To quantify the influence of elasticity number (El) and Weissenberg number (Wi) on impact forces.
- To establish a unified framework for the liquid-to-elastic transition.
Main Methods:
- Direct numerical simulations of a viscoelastic sphere impacting a rigid surface.
- Analysis of impact forces across varying elasticity (El) and relaxation time (Wi) parameters.
- Investigating three impact regimes: capillary-dominated, Wagner scaling, and Hertz scaling.
Main Results:
- Newtonian liquid behavior is recovered at low El or low Wi.
- Elastic-solid behavior emerges at high Wi and high El.
- A smooth transition from Wagner to Hertz scaling is observed in the elastic-memory limit.
- Continuous shift from non-memory to permanent memory materials observed with increasing Wi.
Conclusions:
- The study provides a unified framework for understanding impact dynamics across liquid and solid behaviors.
- The findings offer insights into controlling impact forces and transitions in viscoelastic systems.
- This research bridges classical fluid and solid mechanics theories for impact phenomena.
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