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Updated: May 18, 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
Sphere impact and penetration into wet sand.
J O Marston1, I U Vakarelski, S T Thoroddsen
1Division of Physical Sciences and Engineering, King Abdullah University of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia.
Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics
|September 26, 2012
Summary
Water in sand can surprisingly alter sphere penetration depth, sometimes making it deeper, sometimes shallower. This study quantifies how wet granular materials can lubricate or stiffen, affecting impact dynamics.
Area of Science:
- Physics of granular materials
- Fluid-solid interactions
Background:
- Understanding granular material behavior is crucial in various fields.
- The role of pore fluid in granular impacts is complex and not fully understood.
Purpose of the Study:
- To experimentally investigate the penetration depth of a solid sphere into wet granular material.
- To determine how water content affects the mechanical properties of sand and sphere impact dynamics.
Main Methods:
- Experimental setup involving releasing solid spheres onto varying moisture content sand beds.
- Measurement of final penetration depth for different release heights and sand moisture levels.
- Calculation of effective viscosity based on impact velocity and stopping force.
Main Results:
- Sphere penetration depth in wet sand is sensitive to water-induced cohesion.
- Water can act as a lubricant, reducing penetration, or stiffen the sand, increasing penetration.
- Effective viscosities for wet granular materials were derived, correlating with observed penetration behavior.
Conclusions:
- The presence of water significantly modifies the impact and penetration dynamics of spheres in granular media.
- Cohesion and lubrication effects induced by water must be considered for accurate modeling of wet sand impacts.
- This research provides a method for quantifying the rheological properties of wet granular materials under impact conditions.
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