Nvidia has released a nice little video showing off some of the new APEX Turbulence features of its PhysX physics system, using footage from the free-to-play mech shooter Hawken.
Unlike the SPH-like (Smoothed Particle Hydrodynamics) systems commonly used in games, APEX Turbulence is a grid-based fluid solver, and calculates only surface turbulence and velocity fields.
These forces can then be applied to particles generated with other systems: in this case the APEX Particles module. The result is more detailed fluid flow for things like smoke, dust, fog and plasma effects.
For more info visit: nVidia