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Updates to Aitkens relaxation

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Now completely handled from the sixDOFODE class
This commit is contained in:
Vuko Vukcevic 2017-03-01 16:47:34 +01:00 committed by Hrvoje Jasak
parent 7e0eee0f94
commit c3a38ac471
7 changed files with 180 additions and 239 deletions
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9
src/ODE/ODE/ODE.H
View file

@ -91,15 +91,6 @@ public:
//- Update ODE after the solution, advancing by delta
virtual void update(const scalar delta) = 0;
//- Member function for initialising the ODE state. Required for some
// ODE's (specifically sixDOFODE's) which might be called multiple
// times per single time-step. Called at the beginning of
// ODESolver::solve and does nothing by default
virtual void init()
{
// Does nothing by default
}
};

3
src/ODE/ODESolvers/ODESolver/ODESolver.C
View file

@ -54,9 +54,6 @@ void Foam::ODESolver::solve
scalar& hEst
)
{
// Initialize ODE before solving
ode_.init();
const label MAXSTP = 10000;
scalar x = xStart;

10
src/ODE/sixDOF/geometricSixDOF/geometricSixDOF.C
View file

@ -76,10 +76,8 @@ Foam::dimensionedVector Foam::geometricSixDOF::A
{
// Fix the total force in global coordinate system
dimensionedVector fAbs =
// Force in global coordinate system
// External force
force()
// Force in local coordinate system
+ (R.T() & forceRelative())
// Spring force in global coordinate system
- (linSpringCoeffs() & xR)
// Damping force in global coordinate system
@ -100,10 +98,8 @@ Foam::dimensionedVector Foam::geometricSixDOF::OmegaDot
{
// External moment (torque) in local coordinate system
dimensionedVector mRel =
// Moment in global coordinate system
(dimensionedTensor("R", dimless, R) & moment())
// Moment in local coordinate system
+ momentRelative();
// External moment
(dimensionedTensor("R", dimless, R) & moment());
// Note: constraints not implemented at the moment. They shall be
// implemented in terms of Lagrange multipliers.

5
src/ODE/sixDOF/quaternionSixDOF/quaternionSixDOF.C
View file

@ -62,10 +62,8 @@ Foam::dimensionedVector Foam::quaternionSixDOF::A
{
// Fix the total force in global coordinate system
dimensionedVector fAbs =
// Force in global coordinate system
// External force
force()
// Force in local coordinate system
+ (rotation.invR() & forceRelative())
// Spring force in global coordinate system
- (linSpringCoeffs() & xR)
// Damping force in global coordinate system
@ -96,7 +94,6 @@ Foam::dimensionedVector Foam::quaternionSixDOF::OmegaDot
E(omega)
// To relative
+ (rotation.R() & mAbs)
+ momentRelative()
);
}

262
src/ODE/sixDOF/sixDOFODE/sixDOFODE.C
View file

@ -50,11 +50,7 @@ defineRunTimeSelectionTable(sixDOFODE, dictionary);
// * * * * * * * * * * * * Private Member Functions * * * * * * * * * * * * * //
void Foam::sixDOFODE::aitkensRelaxation
(
const scalar min,
const scalar max
)
void Foam::sixDOFODE::updateRelaxFactors()
{
// Calculate translational relax factor
const scalar saveOldRelFacT = oldRelaxFactorT_;
@ -71,17 +67,17 @@ void Foam::sixDOFODE::aitkensRelaxation
}
else
{
relaxFactorT_ = min;
relaxFactorT_ = minRelaxFactor_;
}
// Bound the relaxation factor for stability
if (relaxFactorT_ > max)
if (relaxFactorT_ > maxRelaxFactor_)
{
relaxFactorT_ = max;
relaxFactorT_ = maxRelaxFactor_;
}
else if (relaxFactorT_ < min)
else if (relaxFactorT_ < minRelaxFactor_)
{
relaxFactorT_ = min;
relaxFactorT_ = minRelaxFactor_;
}
// Calculate rotational relax factor
@ -104,141 +100,35 @@ void Foam::sixDOFODE::aitkensRelaxation
}
else
{
relaxFactorR_ = min;
relaxFactorR_ = minRelaxFactor_;
}
// Bound the relaxation factor for stability
if(relaxFactorR_ > max)
if (relaxFactorR_ > maxRelaxFactor_)
{
relaxFactorR_ = max;
relaxFactorR_ = maxRelaxFactor_;
}
else if(relaxFactorR_ < min)
else if (relaxFactorR_ < minRelaxFactor_)
{
relaxFactorR_ = min;
relaxFactorR_ = minRelaxFactor_;
}
}
// * * * * * * * * * * * Protected Member Functions * * * * * * * * * * * * * //
void Foam::sixDOFODE::setState(const sixDOFODE& sd)
void Foam::sixDOFODE::relaxAcceleration()
{
// Set state does not copy AList_, AOld_, relaxFactor_ and relaxFactorOld_.
// In case of multiple updates, overwriting Aitkens relaxation parameters
// would invalidate the underrelaxation. IG, 5/May/2016
mass_ = sd.mass_;
momentOfInertia_ = sd.momentOfInertia_;
Xequilibrium_ = sd.Xequilibrium_;
linSpringCoeffs_ = sd.linSpringCoeffs_;
linDampingCoeffs_ = sd.linDampingCoeffs_;
force_ = sd.force_;
moment_ = sd.moment_;
forceRelative_ = sd.forceRelative_;
momentRelative_ = sd.momentRelative_;
}
// * * * * * * * * * * * * * * * * Constructors * * * * * * * * * * * * * * //
Foam::sixDOFODE::sixDOFODE(const IOobject& io)
:
ODE(),
dict_(io, *this),
mass_(dict_.lookup("mass")),
momentOfInertia_(dict_.lookup("momentOfInertia")),
Xequilibrium_(dict_.lookup("equilibriumPosition")),
linSpringCoeffs_(dict_.lookup("linearSpring")),
linDampingCoeffs_(dict_.lookup("linearDamping")),
relaxFactorT_(1.0),
relaxFactorR_(1.0),
oldRelaxFactorT_(1.0),
oldRelaxFactorR_(1.0),
A_(3, vector::zero),
OmegaDot_(3, vector::zero),
An_(3, vector::zero),
OmegaDotn_(3, vector::zero),
force_(dict_.lookup("force")),
moment_(dict_.lookup("moment")),
forceRelative_(dict_.lookup("forceRelative")),
momentRelative_(dict_.lookup("momentRelative")),
curTimeIndex_(-1),
oldStatePtr_()
{}
Foam::sixDOFODE::sixDOFODE(const word& name, const sixDOFODE& sd)
:
ODE(),
dict_(sd.dict_),
mass_(sd.mass_),
momentOfInertia_(sd.momentOfInertia_),
Xequilibrium_(sd.Xequilibrium_),
linSpringCoeffs_(sd.linSpringCoeffs_),
linDampingCoeffs_(sd.linDampingCoeffs_),
relaxFactorT_(1.0),
relaxFactorR_(1.0),
oldRelaxFactorT_(1.0),
oldRelaxFactorR_(1.0),
A_(3, vector::zero),
OmegaDot_(3, vector::zero),
An_(3, vector::zero),
OmegaDotn_(3, vector::zero),
force_(sd.force_),
moment_(sd.moment_),
forceRelative_(sd.forceRelative_),
momentRelative_(sd.momentRelative_),
curTimeIndex_(-1),
oldStatePtr_()
{}
// * * * * * * * * * * * * * * * * Destructor * * * * * * * * * * * * * * * //
Foam::sixDOFODE::~sixDOFODE()
{}
// * * * * * * * * * * * * * * * Member Functions * * * * * * * * * * * * * //
const Foam::OutputControlDictionary<Foam::sixDOFODE>&
Foam::sixDOFODE::dict() const
{
return dict_;
}
void Foam::sixDOFODE::relaxAcceleration
(
const scalar minRelFactor,
const scalar maxRelFactor
)
{
if (mag(minRelFactor - maxRelFactor) < SMALL)
if (mag(minRelaxFactor_ - maxRelaxFactor_) < SMALL)
{
// Fixed relaxation
relaxFactorT_ = minRelFactor;
relaxFactorR_ = minRelFactor;
relaxFactorT_ = minRelaxFactor_;
relaxFactorR_ = minRelaxFactor_;
}
else
{
// Use Aitkens relaxation
// Update Aitkens relaxation factor
aitkensRelaxation(minRelFactor, maxRelFactor);
updateRelaxFactors();
// Update non relaxed accelerations
An_[1] = An_[2];
@ -272,7 +162,7 @@ void Foam::sixDOFODE::relaxAcceleration
}
void Foam::sixDOFODE::init()
void Foam::sixDOFODE::initState()
{
// Get time index
const label timeIndex = dict().time().timeIndex();
@ -299,6 +189,113 @@ void Foam::sixDOFODE::init()
}
// * * * * * * * * * * * Protected Member Functions * * * * * * * * * * * * * //
void Foam::sixDOFODE::setState(const sixDOFODE& sd)
{
// Set state does not copy AList_, AOld_, relaxFactor_ and relaxFactorOld_.
// In case of multiple updates, overwriting Aitkens relaxation parameters
// would invalidate the underrelaxation. IG, 5/May/2016
mass_ = sd.mass_;
momentOfInertia_ = sd.momentOfInertia_;
Xequilibrium_ = sd.Xequilibrium_;
linSpringCoeffs_ = sd.linSpringCoeffs_;
linDampingCoeffs_ = sd.linDampingCoeffs_;
force_ = sd.force_;
moment_ = sd.moment_;
}
// * * * * * * * * * * * * * * * * Constructors * * * * * * * * * * * * * * //
Foam::sixDOFODE::sixDOFODE(const IOobject& io)
:
ODE(),
dict_(io, *this),
mass_(dict_.lookup("mass")),
momentOfInertia_(dict_.lookup("momentOfInertia")),
Xequilibrium_(dict_.lookup("equilibriumPosition")),
linSpringCoeffs_(dict_.lookup("linearSpring")),
linDampingCoeffs_(dict_.lookup("linearDamping")),
aitkensRelaxation_
(
dict_.lookupOrDefault<Switch>("useAitkensRelaxation", false)
),
minRelaxFactor_(dict_.lookupOrDefault<scalar>("minRelaxFactor", 0.1)),
maxRelaxFactor_(dict_.lookupOrDefault<scalar>("maxRelaxFactor", 0.5)),
relaxFactorT_(1.0),
relaxFactorR_(1.0),
oldRelaxFactorT_(1.0),
oldRelaxFactorR_(1.0),
A_(3, vector::zero),
OmegaDot_(3, vector::zero),
An_(3, vector::zero),
OmegaDotn_(3, vector::zero),
force_(dict_.lookup("force")),
moment_(dict_.lookup("moment")),
curTimeIndex_(-1),
oldStatePtr_()
{}
Foam::sixDOFODE::sixDOFODE(const word& name, const sixDOFODE& sd)
:
ODE(),
dict_(sd.dict_),
mass_(sd.mass_),
momentOfInertia_(sd.momentOfInertia_),
Xequilibrium_(sd.Xequilibrium_),
linSpringCoeffs_(sd.linSpringCoeffs_),
linDampingCoeffs_(sd.linDampingCoeffs_),
aitkensRelaxation_(sd.aitkensRelaxation_),
minRelaxFactor_(sd.minRelaxFactor_),
maxRelaxFactor_(sd.maxRelaxFactor_),
relaxFactorT_(1.0),
relaxFactorR_(1.0),
oldRelaxFactorT_(1.0),
oldRelaxFactorR_(1.0),
A_(3, vector::zero),
OmegaDot_(3, vector::zero),
An_(3, vector::zero),
OmegaDotn_(3, vector::zero),
force_(sd.force_),
moment_(sd.moment_),
curTimeIndex_(-1),
oldStatePtr_()
{}
// * * * * * * * * * * * * * * * * Destructor * * * * * * * * * * * * * * * //
Foam::sixDOFODE::~sixDOFODE()
{}
// * * * * * * * * * * * * * * * Member Functions * * * * * * * * * * * * * //
const Foam::OutputControlDictionary<Foam::sixDOFODE>&
Foam::sixDOFODE::dict() const
{
return dict_;
}
bool Foam::sixDOFODE::writeData(Ostream& os) const
{
os.writeKeyword("mass") << tab << mass_ << token::END_STATEMENT << nl;
@ -312,14 +309,17 @@ bool Foam::sixDOFODE::writeData(Ostream& os) const
os.writeKeyword("linearDamping") << tab << linDampingCoeffs_
<< token::END_STATEMENT << nl << nl;
os.writeKeyword("useAitkensRelaxation") << tab << aitkensRelaxation_
<< token::END_STATEMENT << nl;
os.writeKeyword("minRelaxFactor") << tab << minRelaxFactor_
<< token::END_STATEMENT << nl;
os.writeKeyword("maxRelaxFactor") << tab << maxRelaxFactor_
<< token::END_STATEMENT << nl;
os.writeKeyword("force") << tab << force_
<< token::END_STATEMENT << nl;
os.writeKeyword("moment") << tab << moment_
<< token::END_STATEMENT << nl;
os.writeKeyword("forceRelative") << tab << forceRelative_
<< token::END_STATEMENT << nl;
os.writeKeyword("momentRelative") << tab << momentRelative_
<< token::END_STATEMENT << endl;
return os.good();
}

73
src/ODE/sixDOF/sixDOFODE/sixDOFODE.H
View file

@ -48,6 +48,7 @@ SourceFiles
#include "autoPtr.H"
#include "OutputControlDictionary.H"
#include "runTimeSelectionTables.H"
#include "Switch.H"
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
@ -92,6 +93,15 @@ class sixDOFODE
// Aitkens relaxation data members
//- Switch to control whether to use Aitkens relaxation
Switch aitkensRelaxation_;
//- Minimum acceleration relaxation factor (default 0.1)
const scalar minRelaxFactor_;
//- Maximum acceleration relaxation factor (default 0.5)
const scalar maxRelaxFactor_;
//- Translational relaxation factor
scalar relaxFactorT_;
@ -116,18 +126,12 @@ class sixDOFODE
// External forces and moments
//- Force driving the motion in inertial coord. sys.
//- Force driving the motion in global (inertial) coord. sys.
dimensionedVector force_;
//- Moment driving the motion in inertial coord. sys.
//- Moment driving the motion in global (inertial) coord. sys.
dimensionedVector moment_;
//- Force driving the motion in relative coord. sys.
dimensionedVector forceRelative_;
//- Moment driving the motion in relative coord. sys.
dimensionedVector momentRelative_;
// Private data used to control multiple ODE updates per time step
// Note: Before solving the ODE from the top level, we will store the
@ -157,7 +161,18 @@ class sixDOFODE
// Aitkens relaxation helper function
//- Update Aitkens relaxation parameters
void aitkensRelaxation(const scalar min, const scalar max);
void updateRelaxFactors();
//- Relax the force (acceleration) using Aitkens or fixed relaxation
void relaxAcceleration();
// Helper function for controlling multiple ODE solver calls per
// time-step
//- Initialise ODE before setting external forces/moments and
// solving
virtual void initState();
protected:
@ -245,41 +260,17 @@ public:
// Access to forces and moments
//- Return force in inertial coord. sys.
//- Return force in global (inertial) coord. sys.
inline const dimensionedVector& force() const;
//- Return access to force in inertial coord. sys.
inline dimensionedVector& force();
//- Return moment in inertial coord. sys.
//- Return moment in global (inertial) coord. sys.
inline const dimensionedVector& moment() const;
//- Return access to moment in inertial coord. sys.
inline dimensionedVector& moment();
//- Return force in relative coord. sys.
inline const dimensionedVector& forceRelative() const;
//- Return access to force in relative coord. sys.
inline dimensionedVector& forceRelative();
//- Return moment in relative coord. sys.
inline const dimensionedVector& momentRelative() const;
//- Return access to moment in relative coord. sys.
inline dimensionedVector& momentRelative();
//- Return total force in inertial coord. sys.
inline dimensionedVector forceTotal() const;
//- Return total moment in inertial coord. sys.
inline dimensionedVector momentTotal() const;
//- Relax the force (acceleration) using Aitkens or fixed relaxation
void relaxAcceleration
//- Set external force and moment
inline void setExternalForceAndMoment
(
const scalar minRelFactor,
const scalar maxRelFactor
const vector& externalForce,
const vector& externalMoment
);
@ -358,10 +349,6 @@ public:
//- Update ODE after the solution, advancing by delta
virtual void update(const scalar delta) = 0;
//- Initialise ODE before solving, handling multiple calls per
// single time step
virtual void init();
// Write control

57
src/ODE/sixDOF/sixDOFODE/sixDOFODEI.H
View file

@ -91,57 +91,30 @@ const Foam::dimensionedVector& Foam::sixDOFODE::force() const
}
Foam::dimensionedVector& Foam::sixDOFODE::force()
{
return force_;
}
const Foam::dimensionedVector& Foam::sixDOFODE::moment() const
{
return moment_;
}
Foam::dimensionedVector& Foam::sixDOFODE::moment()
void Foam::sixDOFODE::setExternalForceAndMoment
(
const vector& externalForce,
const vector& externalMoment
)
{
return moment_;
}
// Initialise the state before setting external forces and moments
initState();
// Set forces and moments
force_ = externalForce;
moment_ = externalMoment;
const Foam::dimensionedVector& Foam::sixDOFODE::forceRelative() const
{
return forceRelative_;
}
Foam::dimensionedVector& Foam::sixDOFODE::forceRelative()
{
return forceRelative_;
}
const Foam::dimensionedVector& Foam::sixDOFODE::momentRelative() const
{
return momentRelative_;
}
Foam::dimensionedVector& Foam::sixDOFODE::momentRelative()
{
return momentRelative_;
}
Foam::dimensionedVector Foam::sixDOFODE::forceTotal() const
{
return force_ + (this->toAbsolute() & forceRelative_);
}
Foam::dimensionedVector Foam::sixDOFODE::momentTotal() const
{
return moment_ + (this->toAbsolute() & momentRelative_);
// Relax acceleration if the Aitkens relaxation is turned on
if (aitkensRelaxation_)
{
relaxAcceleration();
}
}