Simulations of agglomerate collisions with Smooth Particle Hydrodynamics

The initial growth of planetary precursors is accomplished through a sequence of collisions of small meter-sized agglomerates, so called pre-planetesimals. A prerequisite for successful growth is a high sticking probability of the particles after colliding with each other. For solid bodies of cm size or larger the typical collision velocities in protoplanetary disks are in the range of around 1 m/s up to > 50 m/s, depending on the size ratio and the form factor of the bodies. Numerical simulations show that growth by collisions of rocky bodies under these conditions is rather unlikely, and erosion is the primary outcome. However, recent experiments indicate that pre-planetesimals consist of porous macroscopic dust agglomerates rather than solid rocky bodies which behave very differently from solid bodies in collisions. In this project, a comprehensive survey of three dimensional numerical simulations of collisions between dust agglomerates will be performed using porosity models which are calibrated by experimental data from dust experiments.

Principle Investigators

Prof. Dr. Wilhelm Kley
Dr. Roland Speith