[victorconan]

Hi, everyone,
I am new to openfoam. I wanna interpolate the grad(p) but I don't know how to do this. I tried to use fvc::interpolate(fvc::grad(p)), but it does not work. Could anyone do me a favor to teach me how to do this?
Thanks!

PS:I also tried to build a volScalarField and interpolate it, but it did not work. I tried this:
volScalarField surfP
(
IOobject
(
"surfP",
runTime.timeName(),
mesh,
IOobject::NO_READ,
IOobject::AUTO_WRITE
),
mesh,
dimensionedScalar("zero",dimensionSet(0,1,-2,0,0,0,0),0.0)
);
surfP.internalField()=fvc::grad(p);
I suppose there is something wrong with the surfP.internalField()=fvc::grad(p), could anyone tell me how to correct it? Thanks!