yade-users team mailing list archive

[Jan Stránský <question692719@xxxxxxxxxxxxxxxxxxxxx>]

Question #692719 on Yade changed:
https://answers.launchpad.net/yade/+question/692719

    Status: Open => Answered

Jan Stránský proposed the following answer:
Hello,

I have no specific background, but your explanation seems incorrect to
me.

> pump in at a rate Q = 0.05mm^2/s

does this mean that you add 0.05 mm^2/s of new liquid inside the pore?
Below I assume that yes.

> this pore now has ... 0.55 mm^2. The change in volume is 0.05mm^2.
This change in volume will be converted to a change in pressure via the
fluid bulk modulus.

No. The change of volume of the original material causes stress
difference, not change of volume of original + added material.

Also, If you have pore and you enlarge it, how can it convert to pore
pressure? Normally it would lead to pressure decrease / vanishing.

Or you mean that the new liquid causes pressure? It would be the case
for zero (or less then added) volume change (i.e. preserving 0.5 mm^2
also for the new liquid). But if you have original 0.5 volume, you add
0.05 volume and in total you have 0.55 volume, there is no reason for
pressure change..

Am I missing something?

In reality, the surrounding structure does not allow the "pressure-free" expansion, making the real volume less than 0.55.
Then yes, the difference between actual volume and "stress-free" volume (dV) causes pressure. And the proportionality parameter between dV and pressure is liquid bulk modulus.

cheers
Jan

-- 
You received this question notification because your team yade-users is
an answer contact for Yade.