Title: Can Planetesimals form by collisional fusion ?
by
Dhrubaditya Mitra
→
Europe/Stockholm
FA32
FA32
Description
As a test bed for the growth of protoplanetary bodies in a turbulent circumstellar disk we examine the fate of a boulder using direct numerical simulations of particle seeded gas flowing around it.
We provide an accurate description of the flow by imposing no-slip and non-penetrating boundary conditions on the boulder surface using the immersed boundary method of Peskin.
Advected by the turbulent disk flow, the dust grains collide with the boulder and we compute the probability density function (PDF) of the normal component of the collisional velocity.
Through an examination of the collisional statistics we test the recently developed concept of collisional fusion which provides a physical basis for a range of collisional velocities exhibiting perfect sticking.
A boulder can then grow sufficiently rapidly to settle into a Keplerian orbit on disk evolution time scales.
A movie showing the interaction of the boulder with the turbulence in the disk can be found here: http://youtu.be/-Fr5Q2Kp0wo
