localEuler rDeltaT
 

Hi,

I would like to use pimpleFoam in conjunction with "localEuler rDeltaT" as ddtScheme.

But when I start the simulation OF produces the following error message:

"request for volScalarField rDeltaT from objectRegistry region0 failed"

I've checked the tutorials that use this ddtScheme but none of them had a 0/rDeltaT nor did their Allrun-Scripts mention the creation of such a file. I assume the solver itself initializes the file. Why doesn't pimpleFoam do so?

Hope someone can help

Kaskade

When I search github, the solvers with a LTS in their name create the volScalarField rDeltaT themselves. Which probably means that pimpleFoam can't use localEuler.

Hi Kaskade,

I'm also getting the same error, with OF 4.1:
request for volScalarField rDeltaT from objectRegistry

Did you ever find a solution to localEuler for incompressible problems?

Any help is greatly appreciated,
Kind regards,
Kishore

http://www.openfoam.com/documentatio...cal-euler.html

As described in this documentation page, its available only for specific solvers. The solver itself creates a volScalarField rDeltaT object just like any other field for its later usage. If you are "not" using such solver then you will have to modify the solver you are using to include this.

More Info here:
https://www.cfd-online.com/Forums/op...ntralfoam.html

Thank you very much :)

Have you had any success with incorporating it to the pimpleFoam? I'm really new to OpenFOAM, do you think its if I follow the post you shared about localEuler in rhoCentralFoam I would be able to get it done? i.e. is there anything particular that I may have to account for when implementing it to the pimpleFoam?

Thanks again for the swift reply,
Kind regards,
Kishore

I have not implemented it, but it should be doable. Why don't you try and find out? :)
Do share if you implement it.

Regards,

To be honest I can't even remember posting this thread. (Then again, it IS old.)

I'm glad you posted it! Not sure how much benefit it would make on convergence. But if I do implement it I will surely share it here :)

I implemented it for pimpleFoam and buoyantPimpleFoam today but have not done exhaustive testing. You will find the source code and test case for pimpleFoam on my bitbucket repository.

https://bitbucket.org/khedar/pimplefoamlocaleuler/src

Try it out :)

P.S. You have to run using pimpleFoamUser or buoyantPimpleFoamUser

Oh wow! Thank you very much _/|\_ Will do a comparison against simpleFoam with the default relaxation factors and post the results here.

Any particular test case you might have in mind? Guess one of the simpleFoam tutorial case would be good right?

Kind regards,
Kishore

Hi Khedar,
I see the code is no longer available.
Anyone has done some testing with pimpleFoam using Khedar's or someone else's localEuler-able solver?
Kind regards,
-Louis

Hi Louis, I combined all my OpenFoam repos into one. You will find it here:


https://bitbucket.org/khedar/of-dev/src


Let me know if you have trouble finding it.


Regards,
khedar

Thank you Khedar,


By running a diff between your code and the latest OF-dev, I realized that the foundation's pimpleFoam solver already has the localEuler built-in, so I used that one.


I'm running it for a transient flow with a moving mesh within a PIMPLE loop having a fixed timestep set to match the maximal timestep of the localEuler intergation scheme.


I obtain apparently sound results and am able to run without divergence at much higher Courant number than with other ddtSchemes. (I leave all the other schemes unchanged.)

I will do further tests on the validity of the solution, but I am theoretically violating the guidelines which say to only run localEuler on steady flows, but PIMPLE already violates that...
Anyone has comments on this?



Kind regards,




-Louis

Well, I may have been optimistic in my previous post.
The mesh motion is apparently not taken into consideration by the localEuler ddtScheme.
Here are screenshots of the same case of a pitching airfoil computed with localEuler and with backward... I think they speak for themselves...