multiphaseEulerFoam: mixerVessel2D: Made fully incompressible

This now serves as an example of a multiphaseEulerFoam case that
requires pressure referencing.

tutorials/multiphase/multiphaseEulerFoam/laminar/mixerVessel2D/0/p

@@ -16,7 +16,7 @@ FoamFile
 
 dimensions          [1 -1 -2 0 0 0 0];
 
-internalField       uniform 1e5;
+internalField       uniform 0;
 
 boundaryField
 {

tutorials/multiphase/multiphaseEulerFoam/laminar/mixerVessel2D/constant/phaseProperties

@@ -58,11 +58,10 @@ mercury
 air
 {
     type            purePhaseModel;
-    diameterModel   isothermal;
+    diameterModel   constant;
-    isothermalCoeffs
+    constantCoeffs
     {
-        d0              1e-3;
+        d               1e-3;
-        p0              1e5;
     }
 
     residualAlpha 1e-3;

tutorials/multiphase/multiphaseEulerFoam/laminar/mixerVessel2D/constant/thermophysicalProperties.air

@@ -21,7 +21,7 @@ thermoType
     mixture         pureMixture;
     transport       const;
     thermo          hConst;
-    equationOfState perfectGas;
+    equationOfState rhoConst;
     specie          specie;
     energy          sensibleInternalEnergy;
 }
@@ -32,6 +32,10 @@ mixture
     {
         molWeight   28.9;
     }
+    equationOfState
+    {
+        rho         1.16;
+    }
     thermodynamics
     {
         Cp          1007;

tutorials/multiphase/multiphaseEulerFoam/laminar/mixerVessel2D/constant/thermophysicalProperties.water

@@ -21,7 +21,7 @@ thermoType
     mixture         pureMixture;
     transport       const;
     thermo          eConst;
-    equationOfState rPolynomial;
+    equationOfState rhoConst;
     specie          specie;
     energy          sensibleInternalEnergy;
 }
@@ -34,7 +34,7 @@ mixture
     }
     equationOfState
     {
-        C (0.001278 -2.1055e-06 3.9689e-09 4.3772e-13 -2.0225e-16);
+        rho         1000;
     }
     thermodynamics
     {

tutorials/multiphase/multiphaseEulerFoam/laminar/mixerVessel2D/system/fvSolution

@@ -80,8 +80,6 @@ PIMPLE
     nCorrectors     3;
     nNonOrthogonalCorrectors 0;
 
-    pMin            1e4;
-
     pRefCell        0;
     pRefValue       0;
 }