ENH: flowRateVelocityInlet: fall back to rhoInlet

src/finiteVolume/fields/fvPatchFields/derived/flowRateInletVelocity/flowRateInletVelocityFvPatchVectorField.C

@@ -72,7 +72,7 @@ flowRateInletVelocityFvPatchVectorField
 )
 :
     fixedValueFvPatchField<vector>(p, iF),
-    rhoInlet_(0.0)
+    rhoInlet_(dict.lookupOrDefault<scalar>("rhoInlet", -VGREAT))
 {
     if (dict.found("volumetricFlowRate"))
     {
@@ -107,14 +107,9 @@ flowRateInletVelocityFvPatchVectorField
             vectorField("value", dict, p.size())
         );
     }
-    else if (volumetric_)
-    {
-        evaluate(Pstream::blocking);
-    }
     else
     {
-        rhoInlet_ = readScalar(dict.lookup("rhoInlet"));
-        updateCoeffs(rhoInlet_);
+        evaluate(Pstream::blocking);
     }
 }
 
@@ -202,10 +197,30 @@ void Foam::flowRateInletVelocityFvPatchVectorField::updateCoeffs()
     else
     {
         // mass flow-rate
-        const fvPatchField<scalar>& rhop =
-            patch().lookupPatchField<volScalarField, scalar>(rhoName_);
-
-        operator==(n*avgU/rhop);
+        if
+        (
+            patch().boundaryMesh().mesh().foundObject<volScalarField>(rhoName_)
+        )
+        {
+            const fvPatchField<scalar>& rhop =
+                patch().lookupPatchField<volScalarField, scalar>(rhoName_);
+
+            operator==(n*avgU/rhop);
+        }
+        else
+        {
+            // Use constant density
+            if (rhoInlet_ < 0)
+            {
+                FatalErrorIn
+                (
+                    "flowRateInletVelocityFvPatchVectorField::updateCoeffs()"
+                )   << "Did not find registered density field " << rhoName_
+                    << " and no constant density 'rhoInlet' specified"
+                    << exit(FatalError);
+            }
+            operator==(n*avgU/rhoInlet_);
+        }
     }
 
     fixedValueFvPatchField<vector>::updateCoeffs();
@@ -219,7 +234,7 @@ void Foam::flowRateInletVelocityFvPatchVectorField::write(Ostream& os) const
     if (!volumetric_)
     {
         writeEntryIfDifferent<word>(os, "rho", "rho", rhoName_);
-        os.writeKeyword("rhoInlet") << rhoInlet_ << token::END_STATEMENT << nl;
+        writeEntryIfDifferent<scalar>(os, "rhoInlet", -VGREAT, rhoInlet_);
     }
     writeEntry("value", os);
 }

src/finiteVolume/fields/fvPatchFields/derived/flowRateInletVelocity/flowRateInletVelocityFvPatchVectorField.H

@@ -29,7 +29,7 @@ Description
     magnitude as an integral over its area.
 
     Either specify 'volumetricFlowRate' or 'massFlowRate' (requires additional
-    'rho' entry).
+    'rho' or 'rhoInlet' entry).
 
     Example of the boundary condition specification:
     \verbatim
@@ -44,9 +44,10 @@ Description
     inlet
     {
         type                flowRateInletVelocity;
-        volumetricFlowRate  0.2;  // mass flow rate [kg/s]
+        massFlowRate        0.2;  // mass flow rate [kg/s]
         rho                 rho;  // rho [m3/s or kg/s]
-        value               uniform (0 0 0); // placeholder
+        rhoInlet            1.0   // uniform rho if no rho field registered
+                                  // (e.g. at startup)
     }
     \endverbatim
 

tutorials/lagrangian/reactingParcelFoam/verticalChannel/0.org/U

@@ -33,17 +33,13 @@ boundaryField
     {
         type            flowRateInletVelocity;
         massFlowRate    constant 0.00379;
-        //volumetricFlowRate    constant 0.00379;
-        rhoInlet        1.0;
-        value           uniform (0 14.68 0);
+        rhoInlet        1.0;    // fallback value for e.g. potentialFoam
     }
     inletSides
     {
         type            flowRateInletVelocity;
         massFlowRate  constant 0.00832;
-        //volumetricFlowRate  constant 0.00832;
-        rhoInlet        1.0;
-        value           uniform (0 17.79 0);
+        rhoInlet        1.0;    // fallback value for e.g. potentialFoam
     }
     outlet
     {

tutorials/lagrangian/reactingParcelFoam/verticalChannel/Allrun

@@ -14,9 +14,6 @@ runApplication potentialFoam
 
 rm -f 0/phi
 
-# change flowRateInletVelocity to massFlowRate
-runApplication changeDictionary
-
 # run the solver
 runApplication `getApplication`