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functionObject: Fixed bugs in function object time-step adjustment

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The logic governing function objects' ability to change the time-step
has been modified so that it is compatible with the time-step adjustment
done in the Time class. The behaviour has been split into a method which
sets the step directly, and another which moidifies the time until the
next write operation (i.e., the time that the solver "aims" for).

This fixes an issue where the adjustments in Time and the function
objects interfere and cause the time step to decrease exponentially down
to machine precision. It also means that the set-time-step function
object now does not break the adjustable run-time setting.

This resolves bug report https://bugs.openfoam.org/view.php?id=2820
This commit is contained in:
Will Bainbridge
2018-02-05 15:49:14 +00:00
parent 2b76b83343
commit 139ffcc112
10 changed files with 131 additions and 118 deletions
Download Patch File Download Diff File Expand all files Collapse all files

76
src/OpenFOAM/db/Time/Time.C
View File

@ -83,44 +83,34 @@ Foam::word Foam::Time::controlDictName("controlDict");
void Foam::Time::adjustDeltaT()
{
bool adjustTime = false;
scalar timeToNextWrite = vGreat;
scalar timeToNextWrite = max
(
0.0,
(writeTimeIndex_ + 1)*writeInterval_ - (value() - startTime_)
);
if (writeControl_ == wcAdjustableRunTime)
timeToNextWrite = min(timeToNextWrite, functionObjects_.timeToNextWrite());
scalar nSteps = timeToNextWrite/deltaT_;
// For tiny deltaT the label can overflow!
if (nSteps < labelMax)
{
adjustTime = true;
timeToNextWrite = max
(
0.0,
(writeTimeIndex_ + 1)*writeInterval_ - (value() - startTime_)
);
}
label nStepsToNextWrite = label(nSteps + 0.5);
if (adjustTime)
{
scalar nSteps = timeToNextWrite/deltaT_ - small;
scalar newDeltaT = timeToNextWrite/nStepsToNextWrite;
// For tiny deltaT the label can overflow!
if (nSteps < labelMax)
// Control the increase of the time step to within a factor of 2
// and the decrease within a factor of 5.
if (newDeltaT >= deltaT_)
{
label nStepsToNextWrite = label(nSteps) + 1;
scalar newDeltaT = timeToNextWrite/nStepsToNextWrite;
// Control the increase of the time step to within a factor of 2
// and the decrease within a factor of 5.
if (newDeltaT >= deltaT_)
{
deltaT_ = min(newDeltaT, 2.0*deltaT_);
}
else
{
deltaT_ = max(newDeltaT, 0.2*deltaT_);
}
deltaT_ = min(newDeltaT, 2.0*deltaT_);
}
else
{
deltaT_ = max(newDeltaT, 0.2*deltaT_);
}
}
functionObjects_.adjustTimeStep();
}
@ -921,28 +911,32 @@ void Foam::Time::setEndTime(const scalar endTime)
}
void Foam::Time::setDeltaT
(
const dimensionedScalar& deltaT,
const bool bAdjustDeltaT
)
void Foam::Time::setDeltaT(const dimensionedScalar& deltaT)
{
setDeltaT(deltaT.value(), bAdjustDeltaT);
setDeltaT(deltaT.value());
}
void Foam::Time::setDeltaT(const scalar deltaT, const bool bAdjustDeltaT)
void Foam::Time::setDeltaT(const scalar deltaT)
{
deltaT_ = deltaT;
deltaTchanged_ = true;
setDeltaTNoAdjust(deltaT);
if (bAdjustDeltaT)
functionObjects_.setTimeStep();
if (writeControl_ == wcAdjustableRunTime)
{
adjustDeltaT();
}
}
void Foam::Time::setDeltaTNoAdjust(const scalar deltaT)
{
deltaT_ = deltaT;
deltaTchanged_ = true;
}
Foam::TimeState Foam::Time::subCycle(const label nSubCycles)
{
subCycling_ = true;

16
src/OpenFOAM/db/Time/Time.H
View File

@ -516,18 +516,14 @@ public:
virtual void setEndTime(const scalar);
//- Reset time step
virtual void setDeltaT
(
const dimensionedScalar&,
const bool adjustDeltaT = true
);
virtual void setDeltaT(const dimensionedScalar&);
//- Reset time step
virtual void setDeltaT
(
const scalar,
const bool adjustDeltaT = true
);
virtual void setDeltaT(const scalar);
//- Reset time step without additional adjustment or modification
// by function objects
virtual void setDeltaTNoAdjust(const scalar);
//- Set time to sub-cycle for the given number of steps
virtual TimeState subCycle(const label nSubCycles);

10
src/OpenFOAM/db/functionObjects/functionObject/functionObject.C
View File

@ -2,7 +2,7 @@
========= |
\\ / F ield | OpenFOAM: The Open Source CFD Toolbox
\\ / O peration |
\\ / A nd | Copyright (C) 2011-2016 OpenFOAM Foundation
\\ / A nd | Copyright (C) 2011-2018 OpenFOAM Foundation
\\/ M anipulation |
-------------------------------------------------------------------------------
License
@ -140,12 +140,18 @@ bool Foam::functionObject::end()
}
bool Foam::functionObject::adjustTimeStep()
bool Foam::functionObject::setTimeStep()
{
return false;
}
Foam::scalar Foam::functionObject::timeToNextWrite()
{
return vGreat;
}
void Foam::functionObject::updateMesh(const mapPolyMesh&)
{}

12
src/OpenFOAM/db/functionObjects/functionObject/functionObject.H
View File

@ -2,7 +2,7 @@
========= |
\\ / F ield | OpenFOAM: The Open Source CFD Toolbox
\\ / O peration |
\\ / A nd | Copyright (C) 2011-2016 OpenFOAM Foundation
\\ / A nd | Copyright (C) 2011-2018 OpenFOAM Foundation
\\/ M anipulation |
-------------------------------------------------------------------------------
License
@ -230,8 +230,14 @@ public:
// By default it simply calls execute().
virtual bool end();
//- Called at the end of Time::adjustDeltaT() if adjustTime is true
virtual bool adjustTimeStep();
//- Called by Time::setDeltaT(). Allows the function object to override
// the time-step value. Returns whether or not the value was overriden.
virtual bool setTimeStep();
//- Called by Time::adjustTimeStep(). Allows the function object to
// insert a write time earlier than that already in use by the run
// time. Returns the write time, or vGreat.
virtual scalar timeToNextWrite();
//- Update for changes of mesh
virtual void updateMesh(const mapPolyMesh& mpm);

45
src/OpenFOAM/db/functionObjects/functionObjectList/functionObjectList.C
View File

@ -565,9 +565,46 @@ bool Foam::functionObjectList::end()
}
bool Foam::functionObjectList::adjustTimeStep()
bool Foam::functionObjectList::setTimeStep()
{
bool ok = true;
bool set = true;
if (execution_)
{
if (!updated_)
{
read();
}
wordList names;
forAll(*this, objectI)
{
if (operator[](objectI).setTimeStep())
{
names.append(operator[](objectI).name());
set = true;
}
}
if (names.size() > 1)
{
WarningInFunction << "Multiple function objects (" << names[0];
for (label i = 1; i < names.size(); ++ i)
{
WarningInFunction << ", " << names[i];
}
WarningInFunction << ") are setting the time step." << endl;
}
}
return set;
}
Foam::scalar Foam::functionObjectList::timeToNextWrite()
{
scalar result = vGreat;
if (execution_)
{
@ -578,11 +615,11 @@ bool Foam::functionObjectList::adjustTimeStep()
forAll(*this, objectI)
{
ok = operator[](objectI).adjustTimeStep() && ok;
result = min(result, operator[](objectI).timeToNextWrite());
}
}
return ok;
return result;
}

7
src/OpenFOAM/db/functionObjects/functionObjectList/functionObjectList.H
View File

@ -274,8 +274,11 @@ public:
//- Called when Time::run() determines that the time-loop exits
bool end();
//- Called at the end of Time::adjustDeltaT() if adjustTime is true
bool adjustTimeStep();
//- Override the time-step value
bool setTimeStep();
//- Return the time to the next write
scalar timeToNextWrite();
//- Update for changes of mesh
void updateMesh(const mapPolyMesh& mpm);

41
src/OpenFOAM/db/functionObjects/timeControl/timeControlFunctionObject.C
View File

@ -119,48 +119,27 @@ bool Foam::functionObjects::timeControl::end()
bool Foam::functionObjects::timeControl::adjustTimeStep()
Foam::scalar Foam::functionObjects::timeControl::timeToNextWrite()
{
if
(
active()
&& writeControl_.control()
== Foam::timeControl::ocAdjustableRunTime
&& writeControl_.control() == Foam::timeControl::ocAdjustableRunTime
)
{
const label writeTimeIndex = writeControl_.executionIndex();
const scalar writeInterval = writeControl_.interval();
scalar timeToNextWrite = max
(
0.0,
(writeTimeIndex + 1)*writeInterval
- (time_.value() - time_.startTime().value())
);
scalar deltaT = time_.deltaTValue();
scalar nSteps = timeToNextWrite/deltaT - small;
// functionObjects modify deltaT within nStepsToStartTimeChange
// NOTE: Potential problems arise if two function objects dump within
// the same interval
if (nSteps < nStepsToStartTimeChange_)
{
label nStepsToNextWrite = label(nSteps) + 1;
scalar newDeltaT = timeToNextWrite/nStepsToNextWrite;
// Adjust time step
if (newDeltaT < deltaT)
{
deltaT = max(newDeltaT, 0.2*deltaT);
const_cast<Time&>(time_).setDeltaT(deltaT, false);
}
}
return
max
(
0.0,
(writeTimeIndex + 1)*writeInterval
- (time_.value() - time_.startTime().value())
);
}
return true;
return vGreat;
}

4
src/OpenFOAM/db/functionObjects/timeControl/timeControlFunctionObject.H
View File

@ -158,8 +158,8 @@ public:
//- Called when Time::run() determines that the time-loop exits
virtual bool end();
//- Called at the end of Time::adjustDeltaT() if adjustTime is true
virtual bool adjustTimeStep();
//- Return the time to the next write
virtual scalar timeToNextWrite();
//- Read and set the function object if its data have changed
virtual bool read(const dictionary&);

32
src/functionObjects/utilities/setTimeStep/setTimeStepFunctionObject.C
View File

@ -2,7 +2,7 @@
========= |
\\ / F ield | OpenFOAM: The Open Source CFD Toolbox
\\ / O peration |
\\ / A nd | Copyright (C) 2013-2016 OpenFOAM Foundation
\\ / A nd | Copyright (C) 2013-2018 OpenFOAM Foundation
\\/ M anipulation |
-------------------------------------------------------------------------------
License
@ -75,12 +75,11 @@ Foam::functionObjects::setTimeStepFunctionObject::time() const
}
bool Foam::functionObjects::setTimeStepFunctionObject::adjustTimeStep()
bool Foam::functionObjects::setTimeStepFunctionObject::setTimeStep()
{
const_cast<Time&>(time()).setDeltaT
const_cast<Time&>(time()).setDeltaTNoAdjust
(
timeStepPtr_().value(time_.timeOutputValue()),
false
timeStepPtr_().value(time_.timeOutputValue())
);
return true;
@ -94,27 +93,20 @@ bool Foam::functionObjects::setTimeStepFunctionObject::read
{
timeStepPtr_ = Function1<scalar>::New("deltaT", dict);
// Check that adjustTimeStep is active
const dictionary& controlDict = time_.controlDict();
Switch adjust;
if
(
!controlDict.readIfPresent<Switch>("adjustTimeStep", adjust)
|| !adjust
)
{
FatalIOErrorInFunction(dict)
<< "Need to set 'adjustTimeStep' true to allow timestep control"
<< exit(FatalIOError);
}
return true;
}
bool Foam::functionObjects::setTimeStepFunctionObject::execute()
{
bool adjustTimeStep =
time().controlDict().lookupOrDefault("adjustTimeStep", false);
if (!adjustTimeStep)
{
return setTimeStep();
}
return true;
}

6
src/functionObjects/utilities/setTimeStep/setTimeStepFunctionObject.H
View File

@ -2,7 +2,7 @@
========= |
\\ / F ield | OpenFOAM: The Open Source CFD Toolbox
\\ / O peration |
\\ / A nd | Copyright (C) 2013-2017 OpenFOAM Foundation
\\ / A nd | Copyright (C) 2013-2018 OpenFOAM Foundation
\\/ M anipulation |
-------------------------------------------------------------------------------
License
@ -104,8 +104,8 @@ public:
//- Return time database
const Time& time() const;
//- Called at the end of Time::adjustDeltaT() if adjustTime is true
virtual bool adjustTimeStep();
//- Override the time-step value
virtual bool setTimeStep();
//- Read and set the function object if its data have changed
virtual bool read(const dictionary&);