Starting from the stochastic differential equations corresponding to the updating algorithm of dissipative particle dynamics we derive, with a standard technique of projection operators, the hydrodynamic equations for the mass and momentum density fields. The connection of the original parameters of the model with the viscosity and speed of sound of the fluid is clarified.

• Received 17 March 1995

DOI:https://doi.org/10.1103/PhysRevE.52.1734