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[Robert Caulk <question702133@xxxxxxxxxxxxxxxxxxxxx>]

Question #702133 on Yade changed:
https://answers.launchpad.net/yade/+question/702133

    Status: Open => Answered

Robert Caulk proposed the following answer:
Hey Zoheir,

I am assuming the relationship between your gas temperature and the pore
pressure is non-linear? If so, and you want a strong coupling, you'd
need to formulate the fully coupled discretization and solve the two
unknowns (pore temperature and pore pressure) simultaneously using an
iterative approach. We recently did something analogous using a newton-
raphson optimization for volume and pressure in partially saturated
media.

If the fluid flux is linearly related to the pressure field (and still
stoke's flow...big assumption), you could use a weak coupling and it
would be relatively trivial to implement. In this case, you would solve
pressure and temperature as is already implemented in ThermalEngine.
However, you'd then need to use the new temperature to compute mid-step
pore pressures with your non-linear relationship between temperature and
pressure <- this is the piece that would be a trivial implementation in
python or C++. All of this would be followed at the next time-step by
using the existing implementation of solving new pressure field to solve
the fluid fluxes and pressures (and temperatures) at the next timestep.
This weak coupling means you are never truly at equilibrium and you run
the risk of losing stability/accuracy on your solution.

If you wanted a strong coupling, I could advise you or implement it for
you - but it would require significant development hours, and therefore,
I would have little choice but to charge for that kind of software
development.

I hope it helps,

Robert

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