BUG: Delay the call to solidThermo in Radiation BC constructor

in case the solid region has not being constructed yet

src/thermophysicalModels/radiationModels/derivedFvPatchFields/greyDiffusiveRadiation/greyDiffusiveRadiationMixedFvPatchScalarField.C

@@ -102,8 +102,10 @@ greyDiffusiveRadiationMixedFvPatchScalarField
         const scalarField& Tp =
             patch().lookupPatchField<volScalarField, scalar>(TName_);
 
+        //NOTE: Assumes emissivity = 1 as the solidThermo might
+        // not be constructed yet
         refValue() =
-            4.0*physicoChemical::sigma.value()*pow4(Tp)*emissivity()/pi;
+            4.0*physicoChemical::sigma.value()*pow4(Tp)/pi;
         refGrad() = 0.0;
         valueFraction() = 1.0;
 

tutorials/heatTransfer/chtMultiRegionSimpleFoam/multiRegionHeaterRadiation/system/bottomAir/changeDictionaryDict

@@ -174,7 +174,6 @@ dictionaryReplacement
                 type            greyDiffusiveRadiation;
                 T               T;
                 emissivityMode  lookup;
-                Qro             uniform 0;
                 emissivity      uniform 1.0;
                 value           uniform 0;
             }
@@ -184,7 +183,6 @@ dictionaryReplacement
                 type            greyDiffusiveRadiation;
                 T               T;
                 emissivityMode  solidThermo;
-                Qro             uniform 0;
                 value           uniform 0;
             }
         }

tutorials/heatTransfer/chtMultiRegionSimpleFoam/multiRegionHeaterRadiation/system/topAir/changeDictionaryDict

@@ -221,7 +221,6 @@ dictionaryReplacement
                 type            greyDiffusiveRadiation;
                 T               T;
                 emissivityMode  lookup;
-                Qro             uniform 0;
                 emissivity      uniform 1.0;
                 value           uniform 0;
             }
@@ -231,7 +230,6 @@ dictionaryReplacement
                 type            greyDiffusiveRadiation;
                 T               T;
                 emissivityMode  solidThermo;
-                Qro             uniform 0;
                 value           uniform 0;
             }
         }