Jump to content

gas external force in FLIP solver


Recommended Posts

now i understand like this

gas External force is like gravity and someting affect to the field, Geometry

 

noting happen gravity if i turn off apply external force in FLIP solver

 

so i make my test hip file by using Gas external force

but gravity effect is noting happen

 

what a problem?

 

External force.hipnc

Link to comment
Share on other sites

tirst of all the gravity in your file is called Gravity_gravity1 (check the Details view) because Unique Data Name on gravity force is checked 

then it will work, but to see it more clearly

you can temporarily bypass your gasfieldvop1 as that is destroying almost all the input velocity thus making gravity effect almost invisible

Link to comment
Share on other sites

tirst of all the gravity in your file is called Gravity_gravity1 (check the Details view) because Unique Data Name on gravity force is checked 

then it will work, but to see it more clearly

you can temporarily bypass your gasfieldvop1 as that is destroying almost all the input velocity thus making gravity effect almost invisible

 

Thanks!!

i have one more question

case of surface field in gas external force

accroding help file

forces applied on the inside of surface

 

i force value in gravity dop set to positive

and then i can see the v.y attribute value getting increasing value in geometry (i set to geometry in gas externel force)

so like this reason

all i expect is disappear surface field and surfval attribute can get increasing value if positive force value applide to surface field(SDF)

but my expect is wrong..

 

maybe i don't think undestand about it

External force2.hipnc

Edited by sonppw
Link to comment
Share on other sites

the surface field acts as a mask

so geometry inside of the surface field receives the external force the geometry outside doesn't 

but the surface field itself is not modified by that node so you will not see increasing your surfval attribute

 

(on top of that you are recreating surface field at each timestep which would keep it from accumulating the value even if external forces node would modify it)

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...