diff --git a/src/fieldSources/basicSource/rotorDiskSource/rotorDiskSource.C b/src/fieldSources/basicSource/rotorDiskSource/rotorDiskSource.C
index 6014b623fb..c3f042fe01 100644
--- a/src/fieldSources/basicSource/rotorDiskSource/rotorDiskSource.C
+++ b/src/fieldSources/basicSource/rotorDiskSource/rotorDiskSource.C
@@ -465,22 +465,15 @@ Foam::rotorDiskSource::~rotorDiskSource()
 void Foam::rotorDiskSource::calculate
 (
     const vectorField& U,
-    const scalarField& alphag,
+    const scalarField& thetag,
     vectorField& force,
     const bool divideVolume,
     const bool output
 ) const
 {
     const scalarField& V = mesh_.V();
-    const bool compressible = rhoName_ != "none";
-
-    tmp<volScalarField> trho
-    (
-        compressible
-      ? mesh_.lookupObject<volScalarField>(rhoName_)
-      : volScalarField::null()
-    );
-
+    const bool compressible = this->compressible();
+    tmp<volScalarField> trho(rho());
 
     // logging info
     scalar dragEff = 0.0;
@@ -518,7 +511,7 @@ void Foam::rotorDiskSource::calculate
             blade_.interpolate(radius, twist, chord, i1, i2, invDr);
 
             // flip geometric angle if blade is spinning in reverse (clockwise)
-            scalar alphaGeom = alphag[i] + twist;
+            scalar alphaGeom = thetag[i] + twist;
             if (omega_ < 0)
             {
                 alphaGeom = mathematical::pi - alphaGeom;
@@ -685,7 +678,7 @@ bool Foam::rotorDiskSource::read(const dictionary& dict)
 
         if (debug)
         {
-            writeField("alphag", trim_->thetag()(), true);
+            writeField("thetag", trim_->thetag()(), true);
             writeField("faceArea", area_, true);
         }
 
diff --git a/src/fieldSources/basicSource/rotorDiskSource/rotorDiskSource.H b/src/fieldSources/basicSource/rotorDiskSource/rotorDiskSource.H
index a2f856988d..7fd7d33964 100644
--- a/src/fieldSources/basicSource/rotorDiskSource/rotorDiskSource.H
+++ b/src/fieldSources/basicSource/rotorDiskSource/rotorDiskSource.H
@@ -253,7 +253,11 @@ public:
     // Member Functions
 
         // Access
-            
+
+            //- Return the rotational speed [rad/s]
+            //  Positive anti-clockwise when looking along -ve lift direction
+            inline scalar omega() const;
+
             //- Return the cell centre positions in local rotor frame
             // (Cylindrical r, theta, z)
             inline const List<point>& x() const;
@@ -261,6 +265,12 @@ public:
             //- Return the rotor co-ordinate system (r, theta, z)
             inline const cylindricalCS& coordSys() const;
 
+            //- Return true if solving a compressible case
+            inline bool compressible() const;
+
+            //- Return the density field [kg/m3]
+            inline tmp<volScalarField> rho() const;
+
 
         // Evaluation
 
@@ -268,7 +278,7 @@ public:
             void calculate
             (
                 const vectorField& U,
-                const scalarField& alphag,
+                const scalarField& thetag,
                 vectorField& force,
                 const bool divideVolume = true,
                 const bool output = true
diff --git a/src/fieldSources/basicSource/rotorDiskSource/rotorDiskSourceI.H b/src/fieldSources/basicSource/rotorDiskSource/rotorDiskSourceI.H
index 23ca3b0e80..7c194e8713 100644
--- a/src/fieldSources/basicSource/rotorDiskSource/rotorDiskSourceI.H
+++ b/src/fieldSources/basicSource/rotorDiskSource/rotorDiskSourceI.H
@@ -25,6 +25,13 @@ License
 
 #include "rotorDiskSource.H"
 
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+Foam::scalar Foam::rotorDiskSource::omega() const
+{
+    return omega_;
+}
+
 const Foam::List<Foam::point>& Foam::rotorDiskSource::x() const
 {
     return x_;
@@ -37,5 +44,23 @@ const Foam::cylindricalCS& Foam::rotorDiskSource::coordSys() const
 }
 
 
+bool Foam::rotorDiskSource::compressible() const
+{
+    return rhoName_ != "none";
+}
+
+
+Foam::tmp<Foam::volScalarField> Foam::rotorDiskSource::rho() const
+{
+    if (compressible())
+    {
+        return mesh_.lookupObject<volScalarField>(rhoName_);
+    }
+    else
+    {
+        return volScalarField::null();
+    }
+}
+
 // ************************************************************************* //