FLUID DYNAMICS SIMULATION

Hi,

I'm working with fluid dynamics, with air simulation. I haven't been working with grasshopper for a long time, so I'm a little bit lost. I'm trying to model a simulation with a group of points so to be able to see what could happen if I they are moving and they find obstacles in their way, like happens with the movement of the air.
I attached a sketch of what I'm want to do more less. With a mesh of points in the space, wich are being moving in a tube finding obstacles.
Someone could help me with this?
thanks very much ! :)