So I am playing around with using houdini to force smoke to take on shapes and flow where directed. While I think I have figured out how to control shape to a large extent by controlling the temperature and diffusion I keep getting wierd results when I try to use custom velocity fields to control the movement. In this case I want the velocity field to be blasting the smoke at a pretty high velocity, however I can never seem to get the smoke moving any faster then normal. Also if I set the velocity fields to copy in the simulation the smoke does not seem to move. Any ideas what I'm doing wrong?

you have your velocity volumes named N, so it doesn't bind it currently to velocity

so either put N into source_density_from_box/SOP to DOP Bindings/Velocity Volume
or change name of the volume in /obj/box/create_vel_volume1/Velocity Volumes to: vel

Doh! Should have seen that. Thanks!