From 02943424773980c44bced0096f69eef8ab7db198 Mon Sep 17 00:00:00 2001
From: Thomas Fetzer <thomas.fetzer@iws.uni-stuttgart.de>
Date: Tue, 17 Apr 2018 13:18:26 +0200
Subject: [PATCH] [navierstokes] Implement an unsymmetrized version of the
velocity gradient
---
.../navierstokes/staggered/fluxvariables.hh | 56 +++++++++++--------
1 file changed, 33 insertions(+), 23 deletions(-)
diff --git a/dumux/freeflow/navierstokes/staggered/fluxvariables.hh b/dumux/freeflow/navierstokes/staggered/fluxvariables.hh
index 996bf049b2..84168c3e03 100644
--- a/dumux/freeflow/navierstokes/staggered/fluxvariables.hh
+++ b/dumux/freeflow/navierstokes/staggered/fluxvariables.hh
@@ -234,7 +234,11 @@ public:
// The velocity gradient already accounts for the orientation
// of the staggered face's outer normal vector.
const Scalar gradV = (velocityOpposite - velocitySelf) / scvf.selfToOppositeDistance();
- normalFlux -= insideVolVars.effectiveViscosity() * 2.0 * gradV;
+
+ static const bool enableUnsymmetrizedVelocityGradient
+ = getParamFromGroup<bool>(GET_PROP_VALUE(TypeTag, ModelParameterGroup), "FreeFlow.EnableUnsymmetrizedVelocityGradient", false);
+ Scalar factor = enableUnsymmetrizedVelocityGradient ? 1.0 : 2.0;
+ normalFlux -= factor * insideVolVars.effectiveViscosity() * gradV;
// The pressure term.
// If specified, the pressure can be normalized using the initial value on the scfv of interest.
@@ -426,6 +430,9 @@ private:
{
FacePrimaryVariables normalDiffusiveFlux(0.0);
+ static const bool enableUnsymmetrizedVelocityGradient
+ = getParamFromGroup<bool>(GET_PROP_VALUE(TypeTag, ModelParameterGroup), "FreeFlow.EnableUnsymmetrizedVelocityGradient", false);
+
// Get the volume variables of the own and the neighboring element. The neighboring
// element is adjacent to the staggered face normal to the current scvf
// where the dof of interest is located.
@@ -437,33 +444,36 @@ private:
? insideVolVars.effectiveViscosity()
: (insideVolVars.effectiveViscosity() + outsideVolVars.effectiveViscosity()) * 0.5;
- // For the normal gradient, get the velocities perpendicular to the velocity at the current scvf.
- // The inner one is located at staggered face within the own element,
- // the outer one at the respective staggered face of the element on the other side of the
- // current scvf.
- const Scalar innerNormalVelocity = faceVars.velocityNormalInside(localSubFaceIdx);
-
- // Lambda to conveniently get the outer normal velocity for faces that are on the boundary
- // and therefore have no neighbor. Calls the problem to retrieve a fixed value set on the boundary.
- auto getNormalVelocityFromBoundary = [&]()
+ if (!enableUnsymmetrizedVelocityGradient)
{
- const auto ghostFace = makeNormalGhostFace_(scvf, localSubFaceIdx);
- return problem.dirichlet(element, ghostFace)[Indices::velocity(normalFace.directionIndex())];
- };
+ // For the normal gradient, get the velocities perpendicular to the velocity at the current scvf.
+ // The inner one is located at staggered face within the own element,
+ // the outer one at the respective staggered face of the element on the other side of the
+ // current scvf.
+ const Scalar innerNormalVelocity = faceVars.velocityNormalInside(localSubFaceIdx);
+
+ // Lambda to conveniently get the outer normal velocity for faces that are on the boundary
+ // and therefore have no neighbor. Calls the problem to retrieve a fixed value set on the boundary.
+ auto getNormalVelocityFromBoundary = [&]()
+ {
+ const auto ghostFace = makeNormalGhostFace_(scvf, localSubFaceIdx);
+ return problem.dirichlet(element, ghostFace)[Indices::velocity(normalFace.directionIndex())];
+ };
- const Scalar outerNormalVelocity = scvf.hasFrontalNeighbor(localSubFaceIdx)
- ? faceVars.velocityNormalOutside(localSubFaceIdx)
- : getNormalVelocityFromBoundary();
+ const Scalar outerNormalVelocity = scvf.hasFrontalNeighbor(localSubFaceIdx)
+ ? faceVars.velocityNormalOutside(localSubFaceIdx)
+ : getNormalVelocityFromBoundary();
- // Calculate the velocity gradient in positive coordinate direction.
- const Scalar normalDeltaV = scvf.normalInPosCoordDir()
- ? (outerNormalVelocity - innerNormalVelocity)
- : (innerNormalVelocity - outerNormalVelocity);
+ // Calculate the velocity gradient in positive coordinate direction.
+ const Scalar normalDeltaV = scvf.normalInPosCoordDir()
+ ? (outerNormalVelocity - innerNormalVelocity)
+ : (innerNormalVelocity - outerNormalVelocity);
- const Scalar normalGradient = normalDeltaV / scvf.pairData(localSubFaceIdx).normalDistance;
+ const Scalar normalGradient = normalDeltaV / scvf.pairData(localSubFaceIdx).normalDistance;
- // Account for the orientation of the staggered normal face's outer normal vector.
- normalDiffusiveFlux -= muAvg * normalGradient * normalFace.directionSign();
+ // Account for the orientation of the staggered normal face's outer normal vector.
+ normalDiffusiveFlux -= muAvg * normalGradient * normalFace.directionSign();
+ }
// For the parallel derivative, get the velocities at the current (own) scvf
// and at the parallel one at the neighboring scvf.
--
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