fvModels: Added maxDeltaT() function to provide a time-step limiter

fvModels.maxDeltaT() calls are now included in the setDeltaT.H files to
additionally limit the time-step if any fvModel require it.

applications/solvers/combustion/XiFoam/PDRFoam/setDeltaT.H

@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     | Website:  https://openfoam.org
-    \\  /    A nd           | Copyright (C) 2011-2021 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2011-2022 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -33,17 +33,14 @@ Description
 
 if (adjustTimeStep)
 {
-    scalar maxDeltaTFact = maxCo/(CoNum + StCoNum + small);
+    scalar maxDeltaT = maxCo*runTime.deltaTValue()/(CoNum + StCoNum + small);
-    scalar deltaTFact = min(min(maxDeltaTFact, 1.0 + 0.1*maxDeltaTFact), 1.2);
 
-    runTime.setDeltaT
+    maxDeltaT = min(maxDeltaT, fvModels.maxDeltaT());
-    (
+
-        min
+    const scalar deltaT =
-        (
+        min(min(maxDeltaT, 1.0 + 0.1*maxDeltaT), 1.2*runTime.deltaTValue());
-            deltaTFact*runTime.deltaTValue(),
+
-            maxDeltaT
+    runTime.setDeltaT(min(deltaT, maxDeltaT));
-        )
-    );
 
     Info<< "deltaT = " <<  runTime.deltaTValue() << endl;
 }

applications/solvers/compressible/rhoCentralFoam/setDeltaT.H

@@ -0,0 +1,46 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     | Website:  https://openfoam.org
+    \\  /    A nd           | Copyright (C) 2011-2022 OpenFOAM Foundation
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+Global
+    setDeltaT
+
+Description
+    Reset the timestep to maintain a constant maximum courant Number.
+    Reduction of time-step is immediate, but increase is damped to avoid
+    unstable oscillations.
+
+\*---------------------------------------------------------------------------*/
+
+if (adjustTimeStep)
+{
+    scalar maxDeltaT = maxCo*runTime.deltaTValue()/(CoNum + small);
+
+    const scalar deltaT =
+        min(min(maxDeltaT, 1.0 + 0.1*maxDeltaT), 1.2*runTime.deltaTValue());
+
+    runTime.setDeltaT(min(deltaT, maxDeltaT));
+
+    Info<< "deltaT = " <<  runTime.deltaTValue() << endl;
+}
+
+// ************************************************************************* //

applications/solvers/multiphase/twoLiquidMixingFoam/setDeltaT.H

@@ -0,0 +1,48 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     | Website:  https://openfoam.org
+    \\  /    A nd           | Copyright (C) 2011-2022 OpenFOAM Foundation
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+Global
+    setDeltaT
+
+Description
+    Reset the timestep to maintain a constant maximum courant Number.
+    Reduction of time-step is immediate, but increase is damped to avoid
+    unstable oscillations.
+
+\*---------------------------------------------------------------------------*/
+
+if (adjustTimeStep)
+{
+    scalar maxDeltaT =
+        min(maxCo/(CoNum + small), maxAlphaCo/(alphaCoNum + small))
+       *runTime.deltaTValue();
+
+    const scalar deltaT =
+        min(min(maxDeltaT, 1.0 + 0.1*maxDeltaT), 1.2*runTime.deltaTValue());
+
+    runTime.setDeltaT(min(deltaT, maxDeltaT));
+
+    Info<< "deltaT = " <<  runTime.deltaTValue() << endl;
+}
+
+// ************************************************************************* //

src/finiteVolume/cfdTools/general/fvModels/fvModel.C

@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     | Website:  https://openfoam.org
-    \\  /    A nd           | Copyright (C) 2021 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2021-2022 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -146,6 +146,12 @@ bool Foam::fvModel::addsSupToField(const word& fieldName) const
 }
 
 
+Foam::scalar Foam::fvModel::maxDeltaT() const
+{
+    return great;
+}
+
+
 FOR_ALL_FIELD_TYPES(IMPLEMENT_FV_MODEL_ADD_SUP, fvModel);
 
 

src/finiteVolume/cfdTools/general/fvModels/fvModel.H

@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     | Website:  https://openfoam.org
-    \\  /    A nd           | Copyright (C) 2021 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2021-2022 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -258,6 +258,9 @@ public:
             //  field's transport equation
             virtual bool addsSupToField(const word& fieldName) const;
 
+            //- Return the maximum time-step for stable operation
+            virtual scalar maxDeltaT() const;
+
 
         // Sources
 

src/finiteVolume/cfdTools/general/fvModels/fvModels.C

@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     | Website:  https://openfoam.org
-    \\  /    A nd           | Copyright (C) 2021 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2021-2022 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -237,6 +237,21 @@ bool Foam::fvModels::addsSupToField(const word& fieldName) const
 }
 
 
+Foam::scalar Foam::fvModels::maxDeltaT() const
+{
+    const PtrListDictionary<fvModel>& modelList(*this);
+
+    scalar maxDeltaT = great;
+
+    forAll(modelList, i)
+    {
+        maxDeltaT = min(maxDeltaT, modelList[i].maxDeltaT());
+    }
+
+    return maxDeltaT;
+}
+
+
 void Foam::fvModels::preUpdateMesh()
 {
     PtrListDictionary<fvModel>& modelList(*this);

src/finiteVolume/cfdTools/general/fvModels/fvModels.H

@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     | Website:  https://openfoam.org
-    \\  /    A nd           | Copyright (C) 2021 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2021-2022 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -130,6 +130,9 @@ public:
             //  field's transport equation
             virtual bool addsSupToField(const word& fieldName) const;
 
+            //- Return the maximum time-step for stable operation
+            virtual scalar maxDeltaT() const;
+
 
         // Sources
 

src/finiteVolume/cfdTools/general/include/setDeltaT.H

@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     | Website:  https://openfoam.org
-    \\  /    A nd           | Copyright (C) 2011-2018 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2011-2022 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -33,17 +33,14 @@ Description
 
 if (adjustTimeStep)
 {
-    scalar maxDeltaTFact = maxCo/(CoNum + small);
+    scalar maxDeltaT = maxCo*runTime.deltaTValue()/(CoNum + small);
-    scalar deltaTFact = min(min(maxDeltaTFact, 1.0 + 0.1*maxDeltaTFact), 1.2);
 
-    runTime.setDeltaT
+    maxDeltaT = min(maxDeltaT, fvModels.maxDeltaT());
-    (
+
-        min
+    const scalar deltaT =
-        (
+        min(min(maxDeltaT, 1.0 + 0.1*maxDeltaT), 1.2*runTime.deltaTValue());
-            deltaTFact*runTime.deltaTValue(),
+
-            maxDeltaT
+    runTime.setDeltaT(min(deltaT, maxDeltaT));
-        )
-    );
 
     Info<< "deltaT = " <<  runTime.deltaTValue() << endl;
 }

src/twoPhaseModels/twoPhaseMixture/VoF/setDeltaT.H

@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     | Website:  https://openfoam.org
-    \\  /    A nd           | Copyright (C) 2011-2020 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2011-2022 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -33,19 +33,16 @@ Description
 
 if (adjustTimeStep)
 {
-    scalar maxDeltaTFact =
+    scalar maxDeltaT =
-        min(maxCo/(CoNum + small), maxAlphaCo/(alphaCoNum + small));
+        min(maxCo/(CoNum + small), maxAlphaCo/(alphaCoNum + small))
+       *runTime.deltaTValue();
 
-    scalar deltaTFact = min(min(maxDeltaTFact, 1.0 + 0.1*maxDeltaTFact), 1.2);
+    maxDeltaT = min(maxDeltaT, fvModels.maxDeltaT());
 
-    runTime.setDeltaT
+    const scalar deltaT =
-    (
+        min(min(maxDeltaT, 1.0 + 0.1*maxDeltaT), 1.2*runTime.deltaTValue());
-        min
+
-        (
+    runTime.setDeltaT(min(deltaT, maxDeltaT));
-            deltaTFact*runTime.deltaTValue(),
-            maxDeltaT
-        )
-    );
 
     Info<< "deltaT = " <<  runTime.deltaTValue() << endl;
 }