Dynamical and Pressure Structures in Winds with Multiple Embedded   Evaporating Clumps I. 2D Numerical Simulations
  Because of its key role in feedback in star formation and galaxy formation, we examine the nature of the interaction of a flow with discrete sources of mass injection. We show the results of two-dimensional numerical simulations in which we explore a range of configurations for the mass sources and study the effects of their proximity on the downstream flow. The mass sources act effectively as a single source of mass injection if they are so close together that the ratio of their combined mass injection rate is comparable to or exceeds the mass flux of the incident flow into the volume that they occupy. The simulations are relevant to many diffuse sources, such as planetary nebulae and starburst superwinds, in which a global flow interacts with material evaporating or being ablated from the surface of globules of cool, dense gas. 
J. M. Pittard, J. E. Dyson, S. A. E. G. Falle, T. W. Hartquist