Research
Granular Matter
Physics of granular matter has been a main research topic in this research group. A collection of dissipative solid particles (granular matter) shows various intriguing phenomena such as size segregation, convective flow, pattern formation, flow clogging, non-Gaussian statistics, etc. We are striving to reveal the fundamental physics of granular behaviors. In particular, we are interested in the relation between granular physics and planetary and/or geophysical phenomena. Because a lot of astronomical bodies are covered with granular matter called regolith, granular physics is a necessary part for properly understanding planetary surface terrains. Moreover, granular behaviors relate to many other geological and industrial issues. Our goal is to build the granular physics which is relevant to various issues on science and technology. Usually, we perform a simple tabletop experiment.
Mechanical characterization of dust aggregates:
Granular convection and asteroidal resurfacing:
Granular heap relaxation and terrain relaxation:
Mechanical characterization of a hole in wet granular layer for understanding crab's burrow:
Geometry-dpendent granular friction in very slow slip regime:
Orientational ordering in a tapped granular force chain structure:
Force chain characterization in tapped 2D granular lyaer
Obstacle shape effect on granular silo flow:
Previously studied topics are:
Granular impact drag force: paper 1, paper 2, paper 3
Droplet-granular impact cratering: paper 1, paper 2
Jamming and granular heap flow: paper 1, paper 2
Pressure in a vibrated granular bed: paper 1
Granular slow penetration: paper 1, paper 2
Fingering instability in water infiltration to a dry granular layer:
Droplet impact
Relatively old works relating to soft matter and/or nonlinear physics
Polymer gel (surface pattern formation and impact drag force)
Fragmentation (power-law, log-normal, and multi-scaling property)
Rough surface (multi-affine fractal analysis)
