Cloud-cloud collisions

The viscous layer of a stellar cloud is simulated numerically, in order to describe the collision of two clouds at supersonic speeds. The viscosity was constructed using a Smoothed Particle Hydrodynamic (SPH) technique. A series of computer-generated profiles of the velocity fields in the clouds at the moment of collision is given. Analysis of the profiles showed that the collisions generally disrupted and dispersed the clouds instead of coalescing them. Coalescence tended to occur in collisions involving Mach numbers less than about 4, and in clouds with radii greater than 10 pc. It is concluded that the artificial viscosity used in the SPH-scheme model shocks provided an adequate simulation of cloud collision processes. The possibility of including energy effects in future collision simulations is briefly discussed.