---

While molecular gases are well described by established kinetic theories, when macroscopic granular particles replace molecules as the constituents in a granular gas, new challenges arise due to the dissipative nature of their collisions. Including dissipation into the theories leads to three main predictions: 1. non-Maxwellian velocity distributions, 2. homogeneous cooling following the algebraic Haff's law and 3. emergence of cluster instabilities. Experimental test of the theories requires (i) a low-gravity environment, and (ii) external excitation of the granular particles that can drive them into a homogeneous spatial distribution. An experiment - Magnetically Excited Granular Matter (MEGraMa) - was developed at DLR to meet these demands and flown on board of parabolic flights, in a drop tower, and on a sounding rocket. While the first two theoretical predictions can be demonstrated convincingly, quantitative deviations between theory and experiment are apparent.

---

Peidong Yu, DLR and ITP Cologne
Online via Zoom
Contact: Joachim Krug