apply some formatting changes [ci skip]

src/lagrangian/cfdemParticle/cfdTools/versionInfo.H

@@ -39,7 +39,7 @@ word compatibleLIGGGHTSversion="PFM 19.02";
 word OFversion="4.x";
 
 Info << "\nCFDEMcoupling version: " << CFDEMversion <<  endl;
-Info << ", compatible to LIGGGHTS version: " << compatibleLIGGGHTSversion <<  endl;
+Info << "compatible to LIGGGHTS version: " << compatibleLIGGGHTSversion <<  endl;
-Info << ", compatible to OpenFOAM version: " << OFversion <<  endl;
+Info << "compatible to OpenFOAM version: " << OFversion <<  endl;
 
 #endif

src/lagrangian/cfdemParticle/cfdemCloud/cfdemCloud.C

@@ -665,7 +665,7 @@ bool cfdemCloud::evolve
         }
 
         //============================================
-        //CHECK JUST TIME-INTERPOATE ALREADY SMOOTHENED VOIDFRACTIONNEXT AND UsNEXT FIELD
+        //CHECK JUST TIME-INTERPOLATE ALREADY SMOOTHENED VOIDFRACTIONNEXT AND UsNEXT FIELD
         //      IMPLICIT FORCE CONTRIBUTION AND SOLVER USE EXACTLY THE SAME AVERAGED
         //      QUANTITIES AT THE GRID!
         scalar timeStepFrac = dataExchangeM().timeStepFraction();

src/lagrangian/cfdemParticle/subModels/forceModel/BeetstraDrag/BeetstraDrag.H

@@ -17,6 +17,11 @@ Description
     drag law for monodisperse systems according to
     Beetstra et al. AIChE J 53.2 (2007)
 
+Reference
+    R. Beetstra, M.A. van der Hoef, J.A.M. Kuipers
+    "Drag force of intermediate Reynolds number flow past mono- and bidisperse arrays of spheres"
+    AIChE Journal, 53 (2007)
+
 SourceFiles
     BeetstraDrag.C
 \*---------------------------------------------------------------------------*/

src/lagrangian/cfdemParticle/subModels/forceModel/GidaspowDrag/GidaspowDrag.H

@@ -34,6 +34,11 @@ Description
     - splits off explicit drag component due to fluctuation in fluid and particle
       velocity (optional via forceSubModel "ImExCorr")
 
+Reference
+    D. Gidaspow
+    "Multiphase flow and fluidization: Continuum and kinetic theory description",
+    1994
+
 Class
     GidaspowDrag
 

src/lagrangian/cfdemParticle/subModels/forceModel/forceSubModels/forceSubModel/forceSubModel.H

@@ -82,6 +82,7 @@ protected:
 
         List<Switch> switchesList_;         // switches which are requested from dict
 
+        // a Switch is set to false in the default Switch constructor
         List<Switch> switches_;             // switch status
 
         mutable volScalarField nu_;

src/lagrangian/cfdemParticle/subModels/forceModel/interface/interface.H

@@ -28,6 +28,12 @@ Description
     This code is designed to realize coupled CFD-DEM simulations using LIGGGHTS
     and OpenFOAM(R). Note: this code is not part of OpenFOAM(R) (see DISCLAIMER).
 
+Reference
+    G. Wierink, C. Goniva, B. Niceno, K. Heiskanen,
+    "Mechanistic Modelling of Particle-Interface Interaction in Three-Phase Flows",
+    Proc. of the 8th Int. Conf. on CFD in Oil and Gas, Metallurgical and Process Industries,
+    Trondheim, 2011
+
 Class
     interface
 

src/lagrangian/cfdemParticle/subModels/forceModel/virtualMassForce/virtualMassForce.H

@@ -28,6 +28,10 @@ Description
     This code is designed to realize coupled CFD-DEM simulations using LIGGGHTS
     and OpenFOAM(R). Note: this code is not part of OpenFOAM(R) (see DISCLAIMER).
 
+Reference
+    Crowe, Clayton T.; Sommerfeld, Martin; Tsuji, Yutaka (1998).
+    "Multiphase flows with droplets and particles"
+
 Class
     virtualMassForce