[KeiJun]

Dear Sir,

I am now calculating adsorption phenomenon of air (including N2, O2, Ar) using customized reactingFoam.

When executing the tutorial, residuals of U, p, Yi (N2, O2, Ar) change over time as attatched file.
Every residuals falls down at the same time, and after that it isn't be updated any more, though calculation on a terminal continues.

What does this mean?

I have already taken a second look at the equations of the solver, and chaned calculation conditions (maxCo is 0.3, 0.5, 1 / divSchemes is "limitedLinear" to "upwind" / laplacianSchemes is "orthogonal" to "correct" / nOuterCorrectors is 1 to 2, 4 / nNonOrthogonalCorrectors is 0 to 1, 2 / ...), but the result is the same.
Moreover, the time to fall down is almost same in various conditions.

According to the log file, q and Yi apparent valid, but U and p is three times of order as large as I assumed.

I have no idea what this residuals change means and where to have an eye to deal with this.

I am really apprecieated if you give me any advise.


Here, details that I customize are following:
・adsorption rate eqation "∂q/∂t = k*(qe - qi)" is added to the solver in stead of using the reaction rate equation of OF,
where q is the adsorption amount (mol-fluid/kg-adsorbent), k is adsorption rate coefficient (s^-1), qe is equilibrium adsorption amount (mol-fluid/kg-adsorbent).

・effect of decrease of each specie in fluid caused by adsorption is added like this:
・"rhop * Mi * ∂qi/∂t" to right hand side of YiEqn.H
　　　　・"-Σi (rhop * Mi * ∂qi/∂qt) * U" to right hand side of UEqn.H,
where rhop is adsorption density(kg/m3), Mi is molecular weight (kg/mol).

If necessary, I will attatch the source code and tutorial files.


Sincerely yours,

KeiJun

[KeiJun]

Dear Sir,

I have found that every residuals isn't be updated after falling down but it is kept calculated in much small Δt.

Because of much small Δt, it was apparently that every residuals isn't be updated.

Moreover, I have found that the time for every residuals to fall down is when "Final residual" of every YiEqn is equal to "Initial residual" of it.

In detail, "Final residual"s of Uy, Uz, p, N2 and Ar are already equal to "Initial residual"s of them before residuals falling down, respectively, and "Final residual" of O2 comes equal to "Initial residual" of it at the time for residuals to fall down. "Final residual" of Ux is equal to "Initial residual" of it after some time step of residuals falling down.

What does this mean?
Does this mean that every YiEqn has converged?

Indeed, I think composition in each cell ought to keep changing moment by moment due to adsorption, and YiEqn cannot be converged.

If converged, I want calculation to be kept in not much small Δt after convergence.

Could you advise me how to deal with?


Sincerely,

KeiJun




I am now calculating adsorption phenomenon of air (including N2, O2, Ar) using customized reactingFoam.

When executing the tutorial, residuals of U, p, Yi (N2, O2, Ar) change over time as attatched file.
Every residuals falls down at the same time, and after that it isn't be updated any more, though calculation on a terminal continues.

What does this mean?

I have already taken a second look at the equations of the solver, and chaned calculation conditions (maxCo is 0.3, 0.5, 1 / divSchemes is "limitedLinear" to "upwind" / laplacianSchemes is "orthogonal" to "correct" / nOuterCorrectors is 1 to 2, 4 / nNonOrthogonalCorrectors is 0 to 1, 2 / ...), but the result is the same.
Moreover, the time to fall down is almost same in various conditions.

According to the log file, q and Yi apparent valid, but U and p is three times of order as large as I assumed.

I have no idea what this residuals change means and where to have an eye to deal with this.

I am really apprecieated if you give me any advise.

[T.D.]

Hi,
can you send your source code files ?
thanks