[Hgholami]

Dear Foamer
In the source code of newMovingWallVelocityFvPatch, I saw

forAll(Fc_, i)
{
Fc_[i] = patch().patch()[i].centre(points);
}

That seen save position of each center of patch boundary in Fc variable, then base on ddtScheme "Euler" calculate velocity base on difference of two position in old time and present time divided to deltaT.

Up = (Fc_ - oldFc_)/mesh.time().deltaT().value();

For ddtScheme "backward", it also use old.old.Time.
finally replace normal direction of velocity with phi

scalarField phip =
p.patchField<surfaceScalarField, scalar>(fvc::meshPhi(U));

vectorField n = p.nf();
const scalarField& magSf = p.magSf();
scalarField Un = phip/(magSf + VSMALL);

Up += n*(Un - (n & Up));

Do you confirm my realize?