Dissipation of supersonic turbulence in interstellar clouds
J. M. Scalo, W. A. Pumphrey;
ApJ, 1982, 258, L29
ABSTRACT:The dissipation of supersonic turbulent motions in interstellar clouds is reconsidered using N-body
simulations of systems of interacting gas fragments.
The adopted collision rules
are based on recent hydrodynamical studies of cloud collisions.
It is
shown that the preponderance of oblique collisions which dissipate
relatively little kinetic energy results in a dissipation time scale which
exceeds the geometrical collision time scale by a factor of about 20 or
more.
The process of turbulent virialization, whereby cloud gravitational
potential energy is converted into random internal motions, leading to a slow
cloud contraction controlled by the turbulent dissipation rate is also
discussed.
The cloud lifetime can be extended significantly beyond the free-fall
time by this process, without the need for any additional source of
turbulent energy.
This result also suggests an explanation for the apparently
large age difference between globular clusters and the oldest disk stars.
KEYWORDS: interstellar matter, molecular clouds, particle interactions, supersonic flow, turbulent flow, globular clusters, gravitational effects, hydrodynamics, kinetic energy, late stars, many body problem, potential energy
PERSOKEY:turbulence, ,
CODE: scalo82