In a smoke simulation, how can I change the velocity over time?

[Masoud]

Hi;

In a smoke simulation (H18), the velocity seems the same in all areas, but I want the smoke to slow down after a while. Something like air resistance.

How can I change the velocity over time?

 

Thanks.

[Masoud]

Any idea?

[Atom]

Check out the drag by distance example file.

 

[bunker]

// simple drag
v@vel*=clamp(1-chf("drag"),0,1);

 

[schwungsau]

in my experience the best result are, if you handle it like real smoke, control the temperature.

at the source its quite hot --> buoyancy push up the smoke fast, and when it cools down the smoke slow's down, if the temperature drip too fast in some area's, the smoke goes down like in your reference image.