ENH: Adding optional uniform jump switch to fan BC

src/finiteVolume/fields/fvPatchFields/derived/fan/fanFvPatchField.C

@@ -48,7 +48,8 @@ Foam::fanFvPatchField<Type>::fanFvPatchField
 :
     uniformJumpFvPatchField<Type>(p, iF),
     phiName_("phi"),
-    rhoName_("rho")
+    rhoName_("rho"),
+    uniformJump_(false)
 {}
 
 
@@ -62,7 +63,8 @@ Foam::fanFvPatchField<Type>::fanFvPatchField
 :
     uniformJumpFvPatchField<Type>(p, iF, dict),
     phiName_(dict.lookupOrDefault<word>("phi", "phi")),
-    rhoName_(dict.lookupOrDefault<word>("rho", "rho"))
+    rhoName_(dict.lookupOrDefault<word>("rho", "rho")),
+    uniformJump_(dict.lookupOrDefault<bool>("uniformJump", "false"))
 {}
 
 
@@ -77,7 +79,8 @@ Foam::fanFvPatchField<Type>::fanFvPatchField
 :
     uniformJumpFvPatchField<Type>(ptf, p, iF, mapper),
     phiName_(ptf.phiName_),
-    rhoName_(ptf.rhoName_)
+    rhoName_(ptf.rhoName_),
+    uniformJump_(ptf.uniformJump_)
 {}
 
 
@@ -89,7 +92,8 @@ Foam::fanFvPatchField<Type>::fanFvPatchField
 :
     uniformJumpFvPatchField<Type>(ptf),
     phiName_(ptf.phiName_),
-    rhoName_(ptf.rhoName_)
+    rhoName_(ptf.rhoName_),
+    uniformJump_(ptf.uniformJump_)
 {}
 
 
@@ -102,7 +106,8 @@ Foam::fanFvPatchField<Type>::fanFvPatchField
 :
     uniformJumpFvPatchField<Type>(ptf, iF),
     phiName_(ptf.phiName_),
-    rhoName_(ptf.rhoName_)
+    rhoName_(ptf.rhoName_),
+    uniformJump_(ptf.uniformJump_)
 {}
 
 
@@ -129,6 +134,10 @@ void Foam::fanFvPatchField<Type>::write(Ostream& os) const
     uniformJumpFvPatchField<Type>::write(os);
     this->template writeEntryIfDifferent<word>(os, "phi", "phi", phiName_);
     this->template writeEntryIfDifferent<word>(os, "rho", "rho", rhoName_);
+    this->template writeEntryIfDifferent<bool>
+    (
+        os, "uniformJump", false, uniformJump_
+    );
 }
 
 

src/finiteVolume/fields/fvPatchFields/derived/fan/fanFvPatchField.H

@@ -42,6 +42,8 @@ Description
         jumpTable    | jump data, e.g. \c csvFile | yes      |
         phi          | flux field name         | no          | phi
         rho          | density field name      | no          | none
+        uniformJump  | applies a uniform pressure based on the averaged
+                       velocity | no | false
     \endtable
 
     Example of the boundary condition specification:
@@ -109,6 +111,9 @@ class fanFvPatchField
         //  if neccessary
         word rhoName_;
 
+        //- Uniform pressure drop
+        bool uniformJump_;
+
 
     // Private Member Functions
 

src/finiteVolume/fields/fvPatchFields/derived/fan/fanFvPatchFields.C

@@ -44,6 +44,10 @@ void Foam::fanFvPatchField<Foam::scalar>::calcFanJump()
             patch().patchField<surfaceScalarField, scalar>(phi);
 
         scalarField Un(max(phip/patch().magSf(), scalar(0)));
+        if (uniformJump_)
+        {
+             Un = gAverage(Un);
+        }
 
         if (phi.dimensions() == dimDensity*dimVelocity*dimArea)
         {
@@ -67,7 +71,8 @@ Foam::fanFvPatchField<Foam::scalar>::fanFvPatchField
 :
     uniformJumpFvPatchField<scalar>(p, iF),
     phiName_(dict.lookupOrDefault<word>("phi", "phi")),
-    rhoName_(dict.lookupOrDefault<word>("rho", "rho"))
+    rhoName_(dict.lookupOrDefault<word>("rho", "rho")),
+    uniformJump_(dict.lookupOrDefault<bool>("uniformJump", false))
 {
     if (this->cyclicPatch().owner())
     {