> we should use directly crackAperture*crackArea as Vo in dV/Vo, no? That's more or less what I wanted to suggest. I can't explain why I wrote that strange formula. However I also wanted to skip the calculation of crackAperture*crackArea, namely because there can be multiple cracks, as you point out. So my idea was to store the initial value of the numerical porosity in one cell (call it V(t=0)) and to define the cracked volume as the difference V(t)-V(t=0). It makes multiple cracks less a problem I think.
However, an obvious problem of this is that it result in a reference equal to zero when the crack occurs, and we need to divide by this volume... that was the reason to introduce an initial amount of liquid via matrixPorosity (could also depend on slotInitialAperture). Just an idea anyway. The problem of fluid flow inside an advancing crack tip seems fundamentally tough... I can't imagine a perfect answer yet. Bruno -- You received this bug notification because you are a member of Yade developers, which is subscribed to Yade. https://bugs.launchpad.net/bugs/1734653 Title: DFN+fluid compressibility not using the correct reference volume Status in Yade: New Bug description: In the basic PFV scheme the incremental change of density of a pore fluid after a change of pore volume is dependent on dV/Vo where Vo is the reference pore space within a tetrahedral cell [1], i.e. V(tetrahedron)-V(spheres). In DFNFlow "V" should reflect the fact that porosity may be mainly due to a crack an its opening. Typically V=V(tetrahedron)-opening*area-matrixPorosity. Currently it is using the same formula, hence overestimating the compressibility effect (because the DEM porosity is larger than a typical rock porosity). What should be the reference "opening" in above formula is to be clarified though, it has physical as well as numerical implications. Maybe slotInitialAperture is a candidate? Let you DFN people tell what it should be. Note that the "dV" is less a problem because it is a difference (independent on the choice of the reference volume), so the incompressible scheme is not affected. Bruno [1] https://github.com/yade/trunk/blob/master/pkg/pfv/FlowEngine.ipp.in#L439 To manage notifications about this bug go to: https://bugs.launchpad.net/yade/+bug/1734653/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~yade-dev Post to : [email protected] Unsubscribe : https://launchpad.net/~yade-dev More help : https://help.launchpad.net/ListHelp
