[Marpole]

I have worked on this for a few days. I need to output mu during an interFoam run so I can see mu field change as water wave shape changes. I wrote the following code and put it in createField.H. I expect that mixture.mu() calculate mu field at each output time. But I found (viewing using paraFoam) that mu field at each output time doesn't change and is the initial mu field where I set it using setFields. Any help is appreciated!

volScalarField mu
(
    IOobject
    (
        "mu",
        runTime.timeName(),
        mesh,
        IOobject::READ_IF_PRESENT,
        IOobject::AUTO_WRITE
    ),
      mixture.mu()*1.0
);