Space shuttle exhaust -

[cwalrus]

Hey there -

 

I have a nice plume of exhaust squirting out - I want it to curl upwards..... or slow down at the edges. 

 

If it were particles I'd apply POP Axis Force in the shape of a torus... What's the compliment in a voxel sim?

 

thanks!

 

 

cameron

 

 

ps other ideas welcome! - maybe a drag that only applies to an area outside of the primary flame? How do you do that????

 

 

[Annon]

If you close off x/y +/- domains it should do this automagically because of the pressure calculation.

Otherwise there's no reason you can't do the same thing as you do with particles, either in a gasFieldWrangle, vopForce, sopSolver etc... Just apply the velocities to the vel field.

[cwalrus]

Thank you so much for the advice -   can you pretend you're talking to a four year-old? 

 

For example, how do you 'close off x/y +/- domains?'  (maybe you're talking about on the Resize container... which I will try)

 

And how would you use a "gasFieldWrangle, vopForce, sopSolver etc."  specifically? Of course I can find the nodes, but how do I implement that effect with them? 

 

Attached is the project if anyone wants to have a whack at it... 

ExhaustDown_03.hipnc.hiplc.zip

[bluciensky]

Make a field that has the vector information (curl shape), and use the field to advect the smoke - Gas Advect Field.

[cwalrus]

Here's the "HOW TO" that I figured out, in case someone else comes across this and wants specific instructions (like me) :

 

create a particle sim that does what you want the gas to do - in my case, I made a torus of particles, with a POP Axis Force in the shape of a torus spinning them around  .

 

Create that in a POP Network, then pipe that network into a VDB from Particles node. Choose 'velocity trail' from "particle footprint", and click plus to add attribute  - choose v, type in vel in the VDB name bok, and choose Displacement...etc from the Vector Type.

 

Then back in your Pyro network, add a "source volume' and choose the output of above. Choose none for source volume and temp, and choose "add" for velocity. pipe that into the first merge node ... should work!

 

I know there are other ways to do this - but this worked for me

 

thanks!