[zfaraday]

Hi foamers,

It's been quite a while since my last post here, so I know everyone has been missing me a lot since then... But don't worry, here I am again!

I am not foaming hard as I used to during my Master's Thesis but lately I have been doing some very simple tests with chtMultiRegion*Foam and swak4foam. I was trying to use some function objects in order to compute heats and energies in a very simple case and, just out of curiosity, I tried to visualize all the fields and stuff the solver uses by means of the following function object:

    listFields 
    { 
        type listRegisteredObjects; 
        region base;
        outputControlMode timeStep; //startup;
        outputInterval 1; 
    }

Firstly I was using startup mode, but suddenly I tried timeStep mode and something blew my mind. In the following output you will see what shocked me:

Content of object registry base
                                                              Name             Type Autowrite
================================================================== ================ =========
(vol*(-thermo:alpha_copyBySwak4Foam*laplacian(h_copyBySwak4Foam)))         IOobject No
         (vol*(thermo:rho_copyBySwak4Foam*ddt(h_copyBySwak4Foam)))         IOobject No
                                                                 T   volScalarField Yes
                                                        betavSolid         IOobject No
                                                          boundary polyBoundaryMesh No
                                                         cellZones      regIOobject No
                                                              data         IOobject No
                                                         faceZones      regIOobject No
                                                             faces         faceList No
                                                         fvOptions         IOobject No
                                                         fvSchemes       dictionary No
                                                        fvSolution       dictionary No
                                                                 h         IOobject No
                                                               h_0         IOobject No
                                                             h_0_0         IOobject No
                                                         neighbour        labelList No
                                                             owner        labelList No
                                                                 p   volScalarField Yes
                                                        pointZones      regIOobject No
                                                            points      vectorField No
                                               radiationProperties         IOobject No
                                                      thermo:alpha         IOobject No
                                                        thermo:rho         IOobject No
                                          thermophysicalProperties       dictionary No

What on earth are h_0 and h_0_0? These parameters don't show up in the first timestep so I deduce it is something created after the first calculation is done... Is anything related to enthalpy?

I would appreciate any hint you can give me since maybe I can use these parameters as a variable in a function object or something...

Many thanks in advance!

PD: BTW, I'm using OF2.3.x. I'm a little outdated, I know...

[ykanani]

Hi,
I don't know about that specific solver, but "_0" at the end of field names typically correspond to the old time steps. Openfoam stores those when you are using second order time scheme which requires knowledge of the previous timestep(s). That is why you don't have it in the 0 timestep.

see the following code and look for "_0":
OpenFOAM-5.x/src/OpenFOAM/fields/GeometricFields/GeometricField/GeometricField.C


Regards,
Yousef

[zfaraday]

Thanks Yousef for your valuable words. I guessed it was exactly what you said but I was unsure.