diff --git a/dumux/freeflow/stokes/localresidual.hh b/dumux/freeflow/stokes/localresidual.hh index 7951945fc9ad49b28c10fef6210f5e3faee809a4..5c9bfb4e85cee99941b7370d70346fa89fe84b9f 100644 --- a/dumux/freeflow/stokes/localresidual.hh +++ b/dumux/freeflow/stokes/localresidual.hh @@ -328,6 +328,12 @@ protected: { source[momentumXIdx + dimIdx] -= pressureGradAtSCVCenter[dimIdx]; source[momentumXIdx + dimIdx] += volVars.density()*this->problem_().gravity()[dimIdx]; + + // add a wall friction term to account for a dimensional reduction from 3d to 2d + const auto pos = this->element_().geometry().corner(scvIdx); + const Scalar height = this->problem_().extrusionFactorAtPos(pos); + const Scalar wallFriction = 12*volVars.velocity()[dimIdx]*volVars.dynamicViscosity()/(height*height); + source[momentumXIdx + dimIdx] -= wallFriction; } }