Theoretical considerations on colliding clumped winds
  First attempts are made to derive astrophysical implications of the collision of clumped stellar winds from order of magnitude estimates and preliminary numerical simulations. Compared to colliding smooth winds, we find that the most significant differences occur in widely separated systems like WR 140. Clumped winds de-stabilize the wind-wind interaction zone of such systems. Highly compressed, cold knots of WR-wind material can form. Hydrogen rich material is likely to be mixed into these knots by the excited turbulence. Such knots, therefore, are good candidates to form dust. We briefly discuss to what degree our results can be applied to other systems and look at different possibilities for the origin and nature of the inhomogeneities in hot star winds. 
R. Walder, D. Folini