ENH: adding non-dimensional option to fanFvPatchField.C

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

@@ -3,7 +3,7 @@
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     |
     \\  /    A nd           | Copyright (C) 2011-2015 OpenFOAM Foundation
-     \\/     M anipulation  |
+     \\/     M anipulation  | Copyright (C) 2017 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -49,7 +49,10 @@ Foam::fanFvPatchField<Type>::fanFvPatchField
     uniformJumpFvPatchField<Type>(p, iF),
     phiName_("phi"),
     rhoName_("rho"),
-    uniformJump_(false)
+    uniformJump_(false),
+    nonDimensional_(false),
+    rpm_(0.0),
+    dm_(0.0)
 {}
 
 
@@ -64,8 +67,17 @@ Foam::fanFvPatchField<Type>::fanFvPatchField
     uniformJumpFvPatchField<Type>(p, iF, dict),
     phiName_(dict.lookupOrDefault<word>("phi", "phi")),
     rhoName_(dict.lookupOrDefault<word>("rho", "rho")),
-    uniformJump_(dict.lookupOrDefault<bool>("uniformJump", false))
+    uniformJump_(dict.lookupOrDefault<bool>("uniformJump", false)),
-{}
+    nonDimensional_(dict.lookupOrDefault<Switch>("nonDimensional", false)),
+    rpm_(dict.lookupOrDefault<scalar>("rpm", 0.0)),
+    dm_(dict.lookupOrDefault<scalar>("dm", 0.0))
+{
+    if (nonDimensional_)
+    {
+        dict.lookup("rpm") >> rpm_;
+        dict.lookup("dm") >> dm_;
+    }
+}
 
 
 template<class Type>
@@ -80,7 +92,10 @@ Foam::fanFvPatchField<Type>::fanFvPatchField
     uniformJumpFvPatchField<Type>(ptf, p, iF, mapper),
     phiName_(ptf.phiName_),
     rhoName_(ptf.rhoName_),
-    uniformJump_(ptf.uniformJump_)
+    uniformJump_(ptf.uniformJump_),
+    nonDimensional_(ptf.nonDimensional_),
+    rpm_(ptf.rpm_),
+    dm_(ptf.dm_)
 {}
 
 
@@ -93,7 +108,10 @@ Foam::fanFvPatchField<Type>::fanFvPatchField
     uniformJumpFvPatchField<Type>(ptf),
     phiName_(ptf.phiName_),
     rhoName_(ptf.rhoName_),
-    uniformJump_(ptf.uniformJump_)
+    uniformJump_(ptf.uniformJump_),
+    nonDimensional_(ptf.nonDimensional_),
+    rpm_(ptf.rpm_),
+    dm_(ptf.dm_)
 {}
 
 
@@ -107,7 +125,10 @@ Foam::fanFvPatchField<Type>::fanFvPatchField
     uniformJumpFvPatchField<Type>(ptf, iF),
     phiName_(ptf.phiName_),
     rhoName_(ptf.rhoName_),
-    uniformJump_(ptf.uniformJump_)
+    uniformJump_(ptf.uniformJump_),
+    nonDimensional_(ptf.nonDimensional_),
+    rpm_(ptf.rpm_),
+    dm_(ptf.dm_)
 {}
 
 
@@ -138,6 +159,12 @@ void Foam::fanFvPatchField<Type>::write(Ostream& os) const
     (
         os, "uniformJump", false, uniformJump_
     );
+    this->template writeEntryIfDifferent<bool>
+    (
+        os, "nonDimensional", false, nonDimensional_
+    );
+    this->template writeEntryIfDifferent<scalar>(os, "rpm", 0, rpm_);
+    this->template writeEntryIfDifferent<scalar>(os, "dm", 0, dm_);
 }
 
 

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

@@ -3,7 +3,7 @@
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     |
     \\  /    A nd           | Copyright (C) 2011-2016 OpenFOAM Foundation
-     \\/     M anipulation  |
+     \\/     M anipulation  | Copyright (C) 2017 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -34,6 +34,24 @@ Description
     The jump is specified as a \c Function1 type, to enable the use of, e.g.
     contant, polynomial, table values.
 
+    The switch nonDimensional can be used for a non-dimensional table. It needs
+    inputs rpm and dm of the fan. It should be used with uniformJump true.
+
+    The nonDimensional flux for the table is calculate as :
+
+        phi = 4.0*mDot/(rho*sqr(PI)*dm^3*omega)
+        where:
+            dm is the mean diameter.
+            omega is rad/sec.
+
+    The nonDimensinal pressure :
+
+        Psi = 2 deltaP/(rho*(sqr(PI*omega*dm)))
+        where:
+            deltaP is the pressure drop
+
+    The non-dimensional table should be given as Psi = F(phi).
+
 Usage
     \table
         Property     | Description             | Required    | Default value
@@ -43,6 +61,9 @@ Usage
         rho          | density field name      | no          | none
         uniformJump  | applies a uniform pressure based on the averaged
                        velocity | no | false
+        nonDimensional | uses non-dimensional table | no | false
+        rpm          | fan rpm for non-dimensional table | no | 0.0
+        dm           | mean diameter for non-dimensional table | no | 0.0
     \endtable
 
     Example of the boundary condition specification:
@@ -114,6 +135,17 @@ class fanFvPatchField
         //- Uniform pressure drop
         bool uniformJump_;
 
+        //- Swtich for using non-dimensional curve
+        Switch nonDimensional_;
+
+        // Parameters for non-dimensional table
+
+            //- Fan rpm
+            scalar rpm_;
+
+            //- Fan mean diameter
+            scalar dm_;
+
 
     // Private Member Functions
 

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

@@ -3,7 +3,7 @@
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     |
     \\  /    A nd           | Copyright (C) 2011-2017 OpenFOAM Foundation
-     \\/     M anipulation  |
+     \\/     M anipulation  | Copyright (C) 2017 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -48,6 +48,15 @@ void Foam::fanFvPatchField<Foam::scalar>::calcFanJump()
         {
             scalar area = gSum(patch().magSf());
             Un = gSum(Un*patch().magSf())/area;
+
+            if (nonDimensional_)
+            {
+                // Create an adimensional volumetric flow rate
+                Un =
+                    120.0*Un/pow3(constant::mathematical::pi)
+                  * patch().magSf()
+                  / pow3(dm_);
+            }
         }
 
         if (phi.dimensions() == dimDensity*dimVelocity*dimArea)
@@ -55,9 +64,20 @@ void Foam::fanFvPatchField<Foam::scalar>::calcFanJump()
             Un /= patch().lookupPatchField<volScalarField, scalar>(rhoName_);
         }
 
+        if (nonDimensional_)
+        {
+            scalarField deltap = this->jumpTable_->value(Un);
+            // Convert adimensional deltap from curve into deltaP
+            scalarField pdFan =
+                deltap*pow4(constant::mathematical::pi)*rpm_*sqr(dm_)/1800;
+            this->jump_ = max(pdFan, scalar(0));
+        }
+        else
+        {
             this->jump_ = max(this->jumpTable_->value(Un), scalar(0));
         }
     }
+}
 
 
 // * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
@@ -73,7 +93,10 @@ Foam::fanFvPatchField<Foam::scalar>::fanFvPatchField
     uniformJumpFvPatchField<scalar>(p, iF),
     phiName_(dict.lookupOrDefault<word>("phi", "phi")),
     rhoName_(dict.lookupOrDefault<word>("rho", "rho")),
-    uniformJump_(dict.lookupOrDefault<bool>("uniformJump", false))
+    uniformJump_(dict.lookupOrDefault<bool>("uniformJump", false)),
+    nonDimensional_(dict.lookupOrDefault<Switch>("nonDimensional", false)),
+    rpm_(dict.lookupOrDefault<scalar>("rpm", 0.0)),
+    dm_(dict.lookupOrDefault<scalar>("dm", 0.0))
 {
     if (this->cyclicPatch().owner())
     {