Accounting for backflow in hydrodynamic-simulation interfaces
  Methods for building a consistent interface between hydrodynamic and simulation modules is presented. These methods account for the backflow across the hydrodynamic/simulation hyper-surface. The algorithms are efficient, relatively straight-forward to implement, and account for conservation laws across the hyper-surface. The methods also account for the spurious interactions between particles in the backflow and other particles by following the subsequent impact of such particles. Since the number of altered trajectories grows exponentially in time, a cutoff is built into the procedure so that the effects of the backflow are ignored beyond a certain number of collisions 
Scott Pratt
nucl-th