A recent Hrenya group publication titled “Kinetic-theory predictions of clustering instabilities in granular flows: beyond the small-Knudsen-number regime” (Journal of Fluid Mechanics, 738, R2, 2014) was selected as the focus article in a JFM Focus on Fluids piece written by Professor Michel Louge of Cornell University.
The original work, authored by Ph.D. candidate Peter Mitrano and collaborators, shows that kinetic-theory predictions of clustering instabilties perform well despite a violation of their low-Knudsen-number assumption (see figure). This surprising result, reminiscent of a debate in the gas dynamics community, bodes well for the widespread applicability of such models to practical systems – gasifiers used energy production, heat transfer in concentrating solar power plants, ejection of lunar soil upon spacecraft landing, dynamics of rings of Saturn, etc.