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Merry Christmas and a Happy New Year from the Department for Geodynamics and Sedimentology

After a scientifically very successful year, the executive of the Department for Geodynamics and Sedimentology wishes all our members, students and collaborators a peaceful and joyous holiday season and a prosperous New Year.


Unsuccessful landing of Santa and his reindeers at the Cliffs of Moher.
Click image to start movie (animated gif; 8.4 MB).

About our Season’s Greeting Movie:

Distinct Element Method model implementing the interaction of clumped circular particles. Santa and the sledge, the reindeers and harness pieces are unbreakable clumps. Initially their horizontal velocity is fixed to 10 m/s. The cliff top is 20 m above sea level. Once a clump is beyond the edge of the cliff, translation and rotation are freed (a small random spin is applied for a more dramatic fall!). During free-fall acceleration is not damped, but contact forces arising upon impact between clumps and the sea bed are heavily damped (dissipation of kinetic energy). Once a clump enters the water acceleration is also damped (simulating energy dissipated by the drag force of water resistance) and a buoyancy force is applied (density of water = 1g/cc; density of particles comprising the clumps = 0.5 g/cc, suggesting that Santa and the reindeers are rather bloated!). The dynamics in the water are not accurately captured using this simple approach, but both the freefall and the final (equilibrium) state are physically sound.

The model was designed by Martin Schöpfer and run using the PFC2D software.

Department for Geodynamics and Sedimentology
University of Vienna

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