From 85fdc400eb7b7e5f56e0eb8e768aea053aa668ca Mon Sep 17 00:00:00 2001
From: Katharina Heck <katharina.heck@iws.uni-stuttgart.de>
Date: Wed, 25 Jul 2018 11:09:42 +0200
Subject: [PATCH] [cleanup][freeflow] calculate molar flux to mass flux in case
of useMoles false in fluxvariables instead of in ficks law. diffusion laws
should always return the molar flux
---
.../staggered/freeflow/fickslaw.hh | 16 ++++------------
.../compositional/staggered/fluxvariables.hh | 7 +++++--
2 files changed, 9 insertions(+), 14 deletions(-)
diff --git a/dumux/discretization/staggered/freeflow/fickslaw.hh b/dumux/discretization/staggered/freeflow/fickslaw.hh
index 102ce6d88a..f56fde0bd6 100644
--- a/dumux/discretization/staggered/freeflow/fickslaw.hh
+++ b/dumux/discretization/staggered/freeflow/fickslaw.hh
@@ -19,7 +19,7 @@
/*!
* \file
* \brief This file contains the data which is required to calculate
- * diffusive mass fluxes due to molecular diffusion with Fick's law.
+ * diffusive molar fluxes due to molecular diffusion with Fick's law.
*/
#ifndef DUMUX_DISCRETIZATION_STAGGERED_FICKS_LAW_HH
#define DUMUX_DISCRETIZATION_STAGGERED_FICKS_LAW_HH
@@ -118,19 +118,11 @@ public:
flux[compIdx] = avgDensity * tij * (insideMoleFraction - outsideMoleFraction);
}
- const Scalar cumulativeFlux = std::accumulate(flux.begin(), flux.end(), 0.0);
- flux[FluidSystem::getMainComponent(0)] = - cumulativeFlux;
-
// Fick's law (for binary systems) states that the net flux of moles within the bulk phase has to be zero:
// If a given amount of molecules A travel into one direction, the same amount of molecules B have to
- // go into the opposite direction. This, however, means that the net mass flux whithin the bulk phase
- // (given different molecular weigths of A and B) does not have to be zero. We account for this:
- if(!useMoles)
- {
- //convert everything to a mass flux
- for(int compIdx = 0; compIdx < numComponents; ++compIdx)
- flux[compIdx] *= FluidSystem::molarMass(compIdx);
- }
+ // go into the opposite direction.
+ const Scalar cumulativeFlux = std::accumulate(flux.begin(), flux.end(), 0.0);
+ flux[FluidSystem::getMainComponent(0)] = - cumulativeFlux;
return flux;
}
diff --git a/dumux/freeflow/compositional/staggered/fluxvariables.hh b/dumux/freeflow/compositional/staggered/fluxvariables.hh
index 4bfaea1854..9a0d891210 100644
--- a/dumux/freeflow/compositional/staggered/fluxvariables.hh
+++ b/dumux/freeflow/compositional/staggered/fluxvariables.hh
@@ -52,6 +52,7 @@ class FreeflowNCFluxVariablesImpl<TypeTag, DiscretizationMethod::staggered>
using Element = typename FVGridGeometry::GridView::template Codim<0>::Entity;
using SubControlVolumeFace = typename FVElementGeometry::SubControlVolumeFace;
using CellCenterPrimaryVariables = typename GET_PROP_TYPE(TypeTag, CellCenterPrimaryVariables);
+ using FluidSystem = typename GET_PROP_TYPE(TypeTag, FluidSystem);
using ModelTraits = typename GET_PROP_TYPE(TypeTag, ModelTraits);
public:
@@ -73,6 +74,8 @@ public:
{
CellCenterPrimaryVariables flux(0.0);
+ const auto diffusiveFluxes = MolecularDiffusionType::flux(problem, element, fvGeometry, elemVolVars, scvf);
+
for (int compIdx = 0; compIdx < numComponents; ++compIdx)
{
auto upwindTerm = [compIdx](const auto& volVars)
@@ -83,9 +86,9 @@ public:
};
flux[compIdx] = ParentType::advectiveFluxForCellCenter(problem, elemVolVars, elemFaceVars, scvf, upwindTerm);
- }
- flux += MolecularDiffusionType::flux(problem, element, fvGeometry, elemVolVars, scvf);
+ flux[compIdx] += useMoles ? diffusiveFluxes[compIdx] : diffusiveFluxes[compIdx]*FluidSystem::molarMass(compIdx);
+ }
// in case one balance is substituted by the total mass balance
if (ModelTraits::replaceCompEqIdx() < numComponents)
--
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