Collisions between grains in a turbulent gas
H. J. Voelk, G. E. Morfill, S. Roeser, F. C. Jones;
AaA, 1980, 85, 316
ABSTRACT:Turbulent gas motions will induce random velocities of small dust grains that are imbedded in the gas.
Within large eddies the friction forces
from the gas lead to strongly correlated velocities for neighboring
grains, whereas small eddies cause uncorrelated grain motions.
The
nonlinear response of a grain to eddy motion is calculated.
This leads to a
turbulent pressure within the dust component as well as to collisions between
pairs of grains.
The results are evaluated numerically for a Kolmogoroff
spectrum and turbulent collision rates are calculated for molecular clouds and
protostellar environments.
Whereas grain-grain collisions should not modify the
initial size distribution in molecular clouds to a significant extent, they
will lead to an entirely different grain population in protostars.
KEYWORDS: cosmic dust, interstellar gas, particle collisions, turbulence effects, collision rates, grains, kinetic theory, particle size distribution, protostars
PERSOKEY:dust, turbulence, size distribution, ,
CODE: voelk80