how to prevent viscosity 0 to stick to viscosity 1000000

[ino]

i have a box one side has viscosity 0 and the other 100000

so basically one side is water the other some solid object

i cant get the water to run down

a big part of it sticks to the solid part

 

 

[paxsonsa]

I am not sure I understand the problem. You want the less viscous fluid to complete run off but the gradient is causing it to ease off? or do you want more of a solid edge?

[ino]

i want the blue part to complete run off

but its sticks to the white particles

the hole thing is one object whit attributes for viscosity the blue is 0 the white is 1000000

[paxsonsa]

What are you using to change the viscosity? Are you using a attribute transfer? SDF? 

Could you upload your hip if that possible?

[bandini]

Viscosity is solved on the volume grid, not particle to particle, I believe, which is why you are getting some mixed behavior at the intersection of the two values. You can try increasing the flip volume grid resolution and see if that helps.

[ino]

bandini not sure what you mean by flip volume grid resolution cant find any setting like this

if i play whit particle separation and particle radius scale i get better results but still fare away from what i am looking for and the simulations times getting total out of hand

 

test123.hipnc

[ikarus]

Why not just sim them separately since you dont want them to interact?

[ino]

 

never said they should not interact

 

here an exaple which goes more in the direction of my final goal

and showing the same problem

 

the red object has viscosity 10000 and density 200

the rest viscosity 0 and density 1000

 

i can let it simulate for ever if you render it you wont see the red because its covered by the blue

 

[bandini]

bandini not sure what you mean by flip volume grid resolution cant find any setting like this

if i play whit particle separation and particle radius scale i get better results but still fare away from what i am looking for and the simulations times getting total out of hand

 

 

Flip Object Grid Scale. Default of 2 means the grid is 1/2 the resolution of the particles. 1 means it should be the same res as the particles.

 

Also try playing with velocity smoothing in the flip solver. Turn off reseeding, as new particles will be interpolated.

 

Based on what I see in your example, you may also want to play with density. Lower density particles will rise above higher density particles.

[ino]

whit the blue/white box where i have input type of particle field

so the actual particle resolution is different from the particle separation

i can get some nice results by lowering the grid size and playing whit the particle separation

but sim times starts to get really heavy even on low resolutions 

 

whit a flip tank even a grid of .5 not helping but sim times starts to rise by factor 50-100

 

thanks every one so fare

 

hope some one comes whit some solution where i dont need a 1mill dollar computer for the simulation

[sekow]

Adam gave you some good advice already.

different density and the velocity smoothing should get you very far without going up with resolution.

you will never get a hunder percent seperation due how flip works. 

[ino]

what i want to achieve is drop some letters in to water which first submerge the float to the surface 

and then reduce the viscosity of the letters so they mix whit the water whit gas blur to mix the colors to

if i cant get a 100 percent separation well but the problem is currently i have a 100 percent water coverage of the letters

after they float to the surface

 

velocity smoothing has some marginal effect but its near to no effect

as i understood the density he mentioned for the floating and not for the stickiness

the floating works fine

[sekow]

give the floating points a smaller density.

[sekow]

ok tried it, and did not get satisfied results either.

what you could try is dropping rbds into the fluid (don't forget to set up feedback) and sourcing out of that. a bit complicated but I think worth a try.

[eetu]

As has been said, there won't be clear separation because of the way flip works (with volumes).

You could move the viscosity transition zone a bit towards towards the more viscous areas by massaging the viscosity field, but that means that the liquid particles will "corrode" the viscous part of the volume.

Depending on the case, that might be better or worse

 

test123e.hipnc