Forums Technical Discussion weird viscosity behaviour

weird viscosity behaviour

   1075   3   1
User Avatar
NAHASSIA
Member
125 posts
Joined: 6月 2008
Offline
 
Hi

I have this very simple setup wit a flip sphere falling. When I enable viscosity on the solver even wit very low viscosity value on the flip object as one in this example, the fluid get struc in the air and does not keep on falling. As you can see in the mp4, first part without viscosity , second part with.

I'm probably toing somthing wrong but I cant figure out what ?

any help very appreciated
Thanks
Edited by NAHASSIA - 2022年5月17日 07:37:28

Attachments:
GOUTT.mp4 (178.7 KB)
GOUTTE.hipnc (667.6 KB)

 Report
User Avatar
sajadalavi
Member
30 posts
Joined: 5月 2017
Offline
 
Your voxel size is so large that it reacts with the collagen before it hits
It is created by reducing particle separation

Attachments:
Capture.JPG (168.9 KB)

 Report
User Avatar
NAHASSIA
Member
125 posts
Joined: 6月 2008
Offline
 
Thanx a lot for the hint Sajadalavi

But I still don't understand why it has a different behaviour with and without viscosity.
 Report
User Avatar
sajadalavi
Member
30 posts
Joined: 5月 2017
Offline
 
This is due to the concept of fluid function in Houdini
In Houdini, speed, collission, etc. are calculated by volume and then transferred to the particle, which is why this happens.
viscosity works almost like vdb smooth. And as the body softens, the function of the collission is disrupted.
 Report
  • Quick Links