Hello,
I have just implemented a simple spline to interpolate raw data of
capillarity and permeability but I found that there is already such a
function in Dumux.
Which type of spline is implemented? Something like cubic monotonicity
preserving?
How can I use it? For example, would be convenient to call it from the
material laws definition in
/dumux/material/fluidmatrixinteractions/2p
Is there any example?
Kind regards,
Lorenzo
On 03.12.2018 15:41, Gläser, Dennis
Hi Lorenzo,DUMUX/dumux/dumux/material/fluidmatrixinteractions/2p
regarding your point (3):
Let us consider the mass balance equation for one of the phases. Then,
for outflow BCs the flux across the boundary is computed by using the
current pressure gradients. For a darcy flux this would mean
-(K*gradP)*normal is evaluated on the boundary. Afterwards, the flux
is turned into a mass flux by multiplying with the mobility and the
density, for which we typically use a simple upwind scheme. Thus,
these values are obtained from inside the domain, which means that
this only works well as long as you really have a flux leaving the
domain. If the sign flips (essentially an inflow boundary), mobility
and density are not defined.
With respect to your question what the difference is: you could
achieve the same thing manually by implementing the above mentioned
stuff into the neumann() function:
But note that especially for cell-centered schemes the outflow BCs are
rather tricky to realize and personally I would try to avoid them and
restrict myself to Neumann and/or Dirichlet BCs where you actually
know what exactly happens.
Best wishes,
Dennis
------------------------------------------------------------------------
*Von:* Dumux <[email protected]> im Auftrag von
lc <[email protected]>
*Gesendet:* Montag, 3. Dezember 2018 12:37:19
*An:* [email protected]
*Betreff:* [DuMuX] on IMPES, grid adaptation and BCs
Hello,
I have the following questions:
1) Is it possible to run IMPES algorithm in sequential (not implicit)
mode without considering capillarity forces (pressure)?
2) Is it possible to do some sort of grid adaptation, for example
locally refine the (unstructrured) mesh where the water saturation front
becomes steeper? If yes, how, is there any example?
3) What actually the Outflow BC does? What is the difference with Neumann?
Thank you very much!
Kind regards,
Lorenzo
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