[1pnc] Adapt volVars and outputfields

dumux/porousmediumflow/1pnc/implicit/volumevariables.hh

@@ -266,6 +266,13 @@ public:
     Scalar mobility(int pIdx = 0) const
     { return 1.0/fluidState_.viscosity(phaseIdx); }
 
+    /*!
+     * \brief Return the dynamic viscosity \f$\mathrm{[Pa s]}\f$ of the fluid within the
+     *        control volume.
+     */
+    Scalar viscosity(int phaseIdx = 0) const
+    { return fluidState_.viscosity(phaseIdx); }
+
     /*!
      * \brief Return the average porosity \f$\mathrm{[-]}\f$ within the control volume.
      */

dumux/porousmediumflow/1pnc/implicit/vtkoutputfields.hh

@@ -43,9 +43,10 @@ public:
     template <class VtkOutputModule>
     static void init(VtkOutputModule& vtk)
     {
-        vtk.addVolumeVariable([](const auto& volVars){ return volVars.pressure(); }, "pressure");
+        vtk.addVolumeVariable([](const auto& volVars){ return volVars.pressure(phaseIdx); }, "pressure");
         vtk.addVolumeVariable([](const auto& volVars){ return volVars.density(phaseIdx); }, "rho");
-        vtk.addVolumeVariable([](const auto& volVars){ return volVars.porosity(); }, "porosity");
+        vtk.addVolumeVariable([](const auto& volVars){ return volVars.viscosity(phaseIdx); }, "mu");
+        vtk.addVolumeVariable([](const auto& volVars){ return volVars.pressure(phaseIdx) - 1e5; }, "delp");
 
         for (int i = 0; i < numComponents; ++i)
            vtk.addVolumeVariable([i](const auto& volVars){ return volVars.moleFraction(phaseIdx, i); },