From af178649b587214430343343d90d97659bf914cf Mon Sep 17 00:00:00 2001
From: Katharina Heck <katharina.heck@iws.uni-stuttgart.de>
Date: Thu, 5 Sep 2019 15:22:44 +0200
Subject: [PATCH] [freeflow] change diffusive flux computation to mass averaged
reference system and adapt units of fluxes accordingly
---
dumux/freeflow/compositional/navierstokesncmodel.hh | 4 ++--
dumux/freeflow/compositional/staggered/fluxvariables.hh | 8 +++++++-
dumux/freeflow/compositional/volumevariables.hh | 8 ++++++++
dumux/freeflow/nonisothermal/localresidual.hh | 9 +++++----
4 files changed, 22 insertions(+), 7 deletions(-)
diff --git a/dumux/freeflow/compositional/navierstokesncmodel.hh b/dumux/freeflow/compositional/navierstokesncmodel.hh
index c909318257..b7958d0155 100644
--- a/dumux/freeflow/compositional/navierstokesncmodel.hh
+++ b/dumux/freeflow/compositional/navierstokesncmodel.hh
@@ -26,7 +26,7 @@
* \f[
* \frac{\partial \left(\varrho X^\kappa\right)}{\partial t}
* + \nabla \cdot \left( \varrho {\boldsymbol{v}} X^\kappa
- * - (D^\kappa + D_\text{t}) \varrho \frac{M^\kappa}{M} \textbf{grad}\, x^\kappa \right)
+ * - (D^\kappa + D_\text{t}) \varrho \textbf{grad}\, X^\kappa \right)
* - q^\kappa = 0
* \f]
*
@@ -35,7 +35,7 @@
* \frac{\partial \varrho_g}{\partial t}
* + \nabla \cdot \left(
* \varrho {\boldsymbol{v}}
- * - \sum_\kappa (D^\kappa + D_\text{t}) \varrho \frac{M^\kappa}{M} \textbf{grad}\, x^\kappa
+ * - \sum_\kappa (D^\kappa + D_\text{t}) \varrho \textbf{grad}\, X^\kappa
* \right)
* - q = 0
* \f]
diff --git a/dumux/freeflow/compositional/staggered/fluxvariables.hh b/dumux/freeflow/compositional/staggered/fluxvariables.hh
index 32ae6f4610..de283bab6f 100644
--- a/dumux/freeflow/compositional/staggered/fluxvariables.hh
+++ b/dumux/freeflow/compositional/staggered/fluxvariables.hh
@@ -86,7 +86,13 @@ public:
flux[compIdx] = ParentType::advectiveFluxForCellCenter(problem, elemVolVars, elemFaceVars, scvf, upwindTerm);
- flux[compIdx] += useMoles ? diffusiveFluxes[compIdx] : diffusiveFluxes[compIdx]*FluidSystem::molarMass(compIdx);
+ //check for the reference system and adapt units of the diffusive flux accordingly.
+ if (MolecularDiffusionType::referenceSystemFormulation() == ReferenceSystemFormulation::massAveraged)
+ {
+ flux[compIdx] += useMoles ? diffusiveFluxes[compIdx]/FluidSystem::molarMass(compIdx) : diffusiveFluxes[compIdx];
+ }
+ else
+ flux[compIdx] += useMoles ? diffusiveFluxes[compIdx] : diffusiveFluxes[compIdx]*FluidSystem::molarMass(compIdx);
}
// in case one balance is substituted by the total mass balance
diff --git a/dumux/freeflow/compositional/volumevariables.hh b/dumux/freeflow/compositional/volumevariables.hh
index a9ccb5ae87..8be88d881c 100644
--- a/dumux/freeflow/compositional/volumevariables.hh
+++ b/dumux/freeflow/compositional/volumevariables.hh
@@ -245,6 +245,14 @@ public:
return FluidSystem::molarMass(compIdx);
}
+ /*!
+ * \brief Returns the average molar mass \f$\mathrm{[kg/mol]}\f$$ the of the fluid phase.
+ *
+ * \param phaseIdx The phase index
+ */
+ Scalar averageMolarMass(const int phaseIdx = 0) const
+ { return fluidState_.averageMolarMass(phaseIdx); }
+
/*!
* \brief Returns the diffusion coefficient \f$\mathrm{[m^2/s]}\f$
*
diff --git a/dumux/freeflow/nonisothermal/localresidual.hh b/dumux/freeflow/nonisothermal/localresidual.hh
index 773157340b..0a5475a3a7 100644
--- a/dumux/freeflow/nonisothermal/localresidual.hh
+++ b/dumux/freeflow/nonisothermal/localresidual.hh
@@ -25,6 +25,7 @@
#define DUMUX_FREE_FLOW_ENERGY_LOCAL_RESIDUAL_HH
#include <dumux/discretization/method.hh>
+#include <dumux/flux/referencesystem.hh>
namespace Dumux {
@@ -158,11 +159,11 @@ public:
const bool insideIsUpstream = scvf.directionSign() == sign(diffusiveFlux[compIdx]);
const auto& upstreamVolVars = insideIsUpstream ? elemVolVars[scvf.insideScvIdx()] : elemVolVars[scvf.outsideScvIdx()];
- // always use a mass-based calculation for the energy balance
- if (FluxVariables::useMoles)
- diffusiveFlux[compIdx] *= elemVolVars[scvf.insideScvIdx()].molarMass(compIdx);
+ if (FluxVariables::MolecularDiffusionType::referenceSystemFormulation() == ReferenceSystemFormulation::massAveraged)
+ flux[localEnergyBalanceIdx] += diffusiveFlux[compIdx] * upstreamVolVars.componentEnthalpy(compIdx);
+ else
+ flux[localEnergyBalanceIdx] += diffusiveFlux[compIdx] * upstreamVolVars.componentEnthalpy(compIdx)* elemVolVars[scvf.insideScvIdx()].molarMass(compIdx);
- flux[localEnergyBalanceIdx] += diffusiveFlux[compIdx] * upstreamVolVars.componentEnthalpy(compIdx);
}
}
};
--
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