Viscosity not ending by the parameter 1, real Object Friction

[themaxxer]

Hi There

I have a Question. I work with one of the newest Version of Phoenix FD. I tried to achieve a really vicous Fluid stick to a rotating Torus. Is there a Parameter like Friction for Objects? Why is the Viscosty Parameter restricted to 1? I tried alot of Versions but can't achieve what i want.

Kind Regards

David

[Ivaylo Katev]

a didn't see that you started a separate thread and answered in the wishlist thread, but will provide a short answer here too:
use the sticky effect of the wetting (dynamics), and use the per object wetting on/off if some objects must have no liquid friction, unfortunately there is no per object sticky param.

[Fragster]

currently viscosity 1 is almost solid state, but if you have no wetting enabled or the physical effect of the wetting is disabled, the behavior in some cases may be mistaken as not enough viscosity, for example when a source is directed against a wall.

bummer. That's exactly what I'm dealing with. As can be seen here

liquid with viscosity 1 is melting away.
Any hints?

Uh, I should have read the "Can't get the viscosity high enough" thread in advance. So I will try to decrease the gravity...

[Fragster]

So, according to the advises from "Can't get the viscosity high enough" thread, I reduced gravity to 0,1 / 0,0 - this only helped little to improve the sim. The melting was reduced a bit but shape got lost again.
As a 2nd approach, I increased the scene scale to 10. This took much longer. And although this prevents the melt of the liquid, but again the shape gets lost.

- What can I do to preserve the shape?

- SPF is 10, cell size is 0,001m, total cells 48.483.774 and there is still boiling visible. Any hint?

[Ivaylo Katev]

i think the problems are not related, try to simulate with disabled gravity, this may point to the reason for the shape loss
about the boiling, try to use particle based smooth if still not used.

[Fragster]

Here is another try. As you can see, I cranked up the settings.
Overall, it looks better but far from good yet. The cream keeps its shape slightly longer than before... but is still melting.
Maybe there's a workaround to kind of freeze the emitted liquid to avoid melting and boiling?

Preferable would be to achieve that without other 3rd party plugins like Frost.
Is the Phoenix mesher capable of that?

[Ivaylo Katev]

ok, disable the gravity (dynamics) and export the liquid particles (output), then use particle based smooth with value about 30 (rendering)
the particle based smooth will eventually solve the flickering, and the gravity will show us the reason for the shape loss

[Paul Oblomov]

Try to use object, that totaly disables fluid velocity (inject velocity=0 to grid), right after your emitter (u have to enable any channel, called "velocity"). That will solve any issues, ur having atm. I think so.

P.S. I think u can even ask chaos guys to script simple gradient mapped grid as a source, for velocity injection, or any other flip attribute, like viscosity amount or whatever. Or make a lil tutorial

[Fragster]

So, I did another sim with gravity deactivated. Unfortunately, this has brought no improvement. It looks pretty similar to the previous version.
Did not check for the boiling yet but this is not my major concern anyway since the particle based smoothing worked well for previous tests.

Just to clarify, I have to increase the surface tension to get more stiffness, right? Or is it the other way around?

@Paul, do you mean the Motion Velocity Effect in the Phoenix Object Properties?
Your suggestion of script / tutorial sounds good. Ivaylo? Would that be an option?

[Ivaylo Katev]

Just to clarify, I have to increase the surface tension to get more stiffness, right? Or is it the other way around?

if in the test the surface tension is on, 100% this is the reason for the shape loss.
the surface tension pushes any edges inward, disable it if you want to keep the shape.

[Fragster]

checking...

I'll be damned! That does the trick.
So, I have obviously interpreted that parameter the other way around.

Thank you!

[themaxxer]

hi there

the animation below is what i wanted to copy. but in my simulation the fluid got cut in pieces. i will post some pics here.
kind regards david

[themaxxer]

maybe i found out what i did wrong i cranked the "motion velocity effect" all the way down to 0.0 and in other tests to 0.1. then the fluid was cut into pieces. now i tried to crank up the motion velocity effect in the right click menu for my object and it worked. what exactly does this parameter mean?

cheers

[Svetlin.Nikolov]

Hey,

This is the pushing effect of a moving body over the fluid - 1 is the natural effect, and by setting it to less than one or more than one you can make an object push the fluid more strongly or weakly than it should in reality.

Cheers!

[Fragster]

Just a quick update on the latest approach.
Here is the rendered version:

Liquid still has some down movement but I guess that could be fixed by decreasing the gravity.