Class which creates a boundary with Lees-Edwards type periodic boundary conditions. More...

#include <LeesEdwardsBoundary.h>

Inheritance diagram for LeesEdwardsBoundary:

Public Member Functions
void	set (std::function< double(double)> shift, std::function< double(double)> velocity, Mdouble left, Mdouble right, Mdouble down, Mdouble up)
	Sets all boundary properties. More...

void	read (std::istream &is)
	Reads all boundary properties from a stream. More...

void	write (std::ostream &os) const
	Writes all boundary properties to a stream. More...

virtual std::string	getName () const
	Returns the name of the object. More...

LeesEdwardsBoundary *	copy () const
	Creates a copy of the object. More...

Mdouble	getHorizontalDistance (BaseParticle &p, bool &positive)
	Returns distance from given particle to the closest horizontal wall. More...

Mdouble	getVerticalDistance (BaseParticle &p, bool &positive)
	Returns distance from given particle to the closest vertical wall. More...

void	shiftHorizontalPosition (BaseParticle *p, bool positive)
	Applies a horizontal shift to the given particle. More...

void	shiftVerticalPosition (BaseParticle *p, bool positive)
	Applies a vertical shift to the given particle. More...

bool	checkBoundaryAfterParticleMoved (BaseParticle *p, ParticleHandler &pH UNUSED)
	Checks if particle crossed a boundary wall and if so, applies periodic shift. More...

void	createPeriodicParticles (BaseParticle *p, ParticleHandler &pH)
	Creates horizontal and vertical periodic copies of given particle, if needed. More...

void	createHorizontalPeriodicParticles (BaseParticle *p, ParticleHandler &pH)
	Creates horizontal periodic copies of given particle, if needed. More...

void	createVerticalPeriodicParticles (BaseParticle *p, ParticleHandler &pH)
	Creates vertical periodic copies of given particle, if needed. More...

Public Member Functions inherited from BaseBoundary
	BaseBoundary ()
	default constructor. More...

	BaseBoundary (const BaseBoundary &b)
	copy constructor More...

virtual	~BaseBoundary ()
	destructor More...

virtual void	createPeriodicParticles (BaseParticle *P UNUSED, ParticleHandler &pH UNUSED)
	Creates periodic copies of given particle in case of periodic boundaries. More...

virtual bool	checkBoundaryAfterParticleMoved (BaseParticle *P UNUSED, ParticleHandler &pH UNUSED)
	Checks if given particle passed the boundary. More...

virtual void	checkBoundaryBeforeTimeStep (DPMBase *md UNUSED)
	Fills a (3D) boundary with particles. More...

void	setHandler (BoundaryHandler *handler)
	Sets the boundary's BoundaryHandler. More...

BoundaryHandler *	getHandler () const
	Returns the boundary's BoundaryHandler. More...

Public Member Functions inherited from BaseObject
	BaseObject ()
	Default constructor. More...

	BaseObject (const BaseObject &p)
	Copy constructor, copies all the objects BaseObject contains. More...

virtual	~BaseObject ()
	virtual destructor More...

virtual void	moveInHandler (const unsigned int index)
	Except that it is virtual, it does the same thing as setIndex() does. More...

void	setIndex (const unsigned int index)
	Allows one to assign an index to an object in the handler/container. More...

void	setId (const unsigned int id)
	Assigns a unique identifier to each object in the handler (container) which remains constant even after the object is deleted from the container/handler. More...

unsigned int	getIndex () const
	Returns the index of the object in the handler. More...

unsigned int	getId () const
	Returns the unique identifier of any particular object. More...

Private Attributes
Mdouble	left_

Mdouble	right_
	(signed) Horizontal distance between the left wall and the origin More...

Mdouble	down_
	(signed) Horizontal distance between the right wall and the origin More...

Mdouble	up_
	(signed) Vertical distance between the bottom wall and the origin More...

std::function< double(double)>	shift_
	(signed) Vertical distance between the top wall and the origin More...

std::function< double(double)>	velocity_

Detailed Description

Class which creates a boundary with Lees-Edwards type periodic boundary conditions.

See also [insert link to the original paper by LE]. Inherits from BaseBoundary.

Todo:

Add link to paper by Lees-Edwards in the documentation of this class.

Is implemented for 2D only now. Needs extension to 3D.

Definition at line 42 of file LeesEdwardsBoundary.h.

Member Function Documentation

bool LeesEdwardsBoundary::checkBoundaryAfterParticleMoved	(	BaseParticle *	p,
		ParticleHandler &pH	UNUSED
	)

Checks if particle crossed a boundary wall and if so, applies periodic shift.

Checks if the particle has to be shifted into the main domain (i.e., if the particle has crossed any of the boundary walls) and if so performs the shift

Parameters

[in] p A pointer to the BaseParticle that is checked

Definition at line 263 of file LeesEdwardsBoundary.cc.

References getHorizontalDistance(), getVerticalDistance(), shiftHorizontalPosition(), and shiftVerticalPosition().

 {
     bool positive;
     while (getVerticalDistance(*p, positive) < 0)
     {
         shiftVerticalPosition(p, positive);
     }
     while (getHorizontalDistance(*p, positive) < 0)
     {
         shiftHorizontalPosition(p, positive);
     }
     return false;
 }

LeesEdwardsBoundary * LeesEdwardsBoundary::copy ( ) const

virtual

Creates a copy of the object.

Copy method; creates a copy on the heap and returns its pointer.

Returns: pointer to the copy on the heap

Implements BaseBoundary.

Definition at line 87 of file LeesEdwardsBoundary.cc.

 {
     return new LeesEdwardsBoundary(*this);
 }

void LeesEdwardsBoundary::createHorizontalPeriodicParticles	(	BaseParticle *	p,
		ParticleHandler &	pH
	)

Creates horizontal periodic copies of given particle, if needed.

Check if periodic copies of the particle in horizontal direction have to be made (i.e., if the distance of the particle to either of the horizontal boundary walls is smaller than its radius plus the radius of the largest particle in the system), and if so makes them

Parameters

[in]	p	A pointer to the BaseParticle that is checked
[out]	pH	A reference to the ParticleHandler where periodic copies will be added

Definition at line 181 of file LeesEdwardsBoundary.cc.

References ParticleHandler::addObject(), BaseParticle::copy(), BaseInteractable::copyInteractionsForPeriodicParticles(), getHorizontalDistance(), BaseParticle::getInteractionRadius(), ParticleHandler::getLargestParticle(), BaseParticle::getPeriodicFromParticle(), BaseParticle::setPeriodicFromParticle(), and shiftHorizontalPosition().

Referenced by createPeriodicParticles(), and createVerticalPeriodicParticles().

 {
     bool positive;      // TRUE if the particle is closest to the left boundary 
                         // wall (set by getVerticalDistance in the following if-statement)
     // check if particle is close enough to either of the walls
     if (getHorizontalDistance(*p, positive) < p->getInteractionRadius() + pH.getLargestParticle()->getInteractionRadius())
     {
         // create a periodic copy of the particle
         BaseParticle* F0 = p->copy();
         pH.addObject(F0);
         F0->copyInteractionsForPeriodicParticles(*p);
 
         // If Particle is doubly shifted, get correct original particle
         BaseParticle* From = p;
         while (From->getPeriodicFromParticle() != nullptr)
             From = From->getPeriodicFromParticle();
         F0->setPeriodicFromParticle(From);
         
         // shift the copy to the 'periodic' position
         shiftHorizontalPosition(F0, positive);
         
         // NB: No extra creation of possible vertical copies of the horizontal copy 
         // here (as compared to createVerticalPeriodicParticles), because these would
         // overlap with the extra creation of horizontal copies in createVerticalPeriodicParticles.
     }
 }

void LeesEdwardsBoundary::createPeriodicParticles	(	BaseParticle *	p,
		ParticleHandler &	pH
	)

Creates horizontal and vertical periodic copies of given particle, if needed.

Check if periodic copies of the particle have to be made for the contact detection and if so makes them

Parameters

[in]	p	A pointer to the BaseParticle that is checked
[out]	pH	A reference to the ParticleHandler where periodic copies will be added

Definition at line 252 of file LeesEdwardsBoundary.cc.

References createHorizontalPeriodicParticles(), and createVerticalPeriodicParticles().

 {
     createVerticalPeriodicParticles(p, pH);
     createHorizontalPeriodicParticles(p, pH);
 }

void LeesEdwardsBoundary::createVerticalPeriodicParticles	(	BaseParticle *	p,
		ParticleHandler &	pH
	)

Creates vertical periodic copies of given particle, if needed.

Check if periodic copies of the particle in vertical direction have to be made (i.e., if the distance of the particle to either of the vertical boundary walls is smaller than its radius plus the radius of the largest particle in the system), and if so makes them

Parameters

[in]	p	A pointer to the BaseParticle that is checked
[out]	pH	A reference to the ParticleHandler where periodic copies will be added

Definition at line 216 of file LeesEdwardsBoundary.cc.

References ParticleHandler::addObject(), BaseParticle::copy(), BaseInteractable::copyInteractionsForPeriodicParticles(), createHorizontalPeriodicParticles(), getHorizontalDistance(), BaseParticle::getInteractionRadius(), ParticleHandler::getLargestParticle(), BaseHandler< T >::getLastObject(), BaseParticle::getPeriodicFromParticle(), getVerticalDistance(), BaseParticle::setPeriodicFromParticle(), shiftHorizontalPosition(), and shiftVerticalPosition().

Referenced by createPeriodicParticles().

 {
     bool positive;      // TRUE if the particle is closest to the bottom boundary 
                         // wall (set by getVerticalDistance in the following if-statement)
     // check if particle is close enough to either of the walls
     if (getVerticalDistance(*p, positive) < p->getInteractionRadius() + pH.getLargestParticle()->getInteractionRadius())
     {   
         // create a periodic copy of the particle
         BaseParticle* F0 = p->copy();
         pH.addObject(F0);
         F0->copyInteractionsForPeriodicParticles(*p);
 
         // If Particle is doubly shifted, get correct original particle
         BaseParticle* From = p;
         while (From->getPeriodicFromParticle() != nullptr)
             From = From->getPeriodicFromParticle();
         F0->setPeriodicFromParticle(From);
         
         // shift the copy to the 'periodic' position
         shiftVerticalPosition(F0, positive);
         while (getHorizontalDistance(*F0, positive) < 0)
         {
             shiftHorizontalPosition(F0, positive);
         }
         
         // Create horizontal periodic copies of the copy particle, if needed (i.e.,
         // if the original particle is in one of the boundary corners).
         createHorizontalPeriodicParticles(pH.getLastObject(), pH);
     }
 }

Mdouble LeesEdwardsBoundary::getHorizontalDistance	(	BaseParticle &	p,
		bool &	positive
	)

Returns distance from given particle to the closest horizontal wall.

Returns the distance between BaseParticle p and the closest boundary wall in horizontal direction

Parameters

[in]	p	A reference to the BaseParticle
[out]	positive	A boolean which is true when the left wall is closest

Returns: The distance to the closes wall in horizontal direction

Definition at line 98 of file LeesEdwardsBoundary.cc.

References BaseInteractable::getPosition(), left_, right_, and Vec3D::X.

Referenced by checkBoundaryAfterParticleMoved(), createHorizontalPeriodicParticles(), and createVerticalPeriodicParticles().

 {
     Mdouble left = p.getPosition().X - left_;
     Mdouble right = right_ - p.getPosition().X;
     if (left < right)
     {
         positive = true;
         return left;
     } else
     {
         positive = false;
         return right;
     }
 }

std::string LeesEdwardsBoundary::getName ( ) const

virtual

Returns the name of the object.

Returns: The name of this object (i.e. "LeesEdwardsBoundary")

Implements BaseObject.

Definition at line 78 of file LeesEdwardsBoundary.cc.

 {
     return "LeesEdwardsBoundary";
 }

Mdouble LeesEdwardsBoundary::getVerticalDistance	(	BaseParticle &	p,
		bool &	positive
	)

Returns distance from given particle to the closest vertical wall.

Returns the distance between BaseParticle p and the closest wall in vertical direction

Parameters

[in]	p	A reference to the BaseParticle
[out]	positive	A boolean which is true when the bottom wall is closest

Returns: The distance to the closes wall in vertical direction

Definition at line 119 of file LeesEdwardsBoundary.cc.

References down_, BaseInteractable::getPosition(), up_, and Vec3D::Y.

Referenced by checkBoundaryAfterParticleMoved(), and createVerticalPeriodicParticles().

 {
     Mdouble down = p.getPosition().Y - down_;
     Mdouble up = up_ - p.getPosition().Y;
     if (down < up)
     {
         positive = true;
         return down;
     } else
     {
         positive = false;
         return up;
     }
 }

void LeesEdwardsBoundary::read ( std::istream & is )

virtual

Reads all boundary properties from a stream.

Reads all the properties of the LeesEdwardsBoundary from an std::istream

Parameters

[in,out] is The stream from which the parameters are read

Implements BaseBoundary.

Definition at line 53 of file LeesEdwardsBoundary.cc.

References down_, left_, BaseBoundary::read(), right_, shift_, UNUSED, up_, and velocity_.

 {
     std::string dummy;
     BaseBoundary::read(is);
     Mdouble shift;
     Mdouble velocity;
     is>>dummy>>left_>>dummy>>right_>>dummy>>down_>>dummy>>up_>>dummy>>shift>>dummy>>velocity;
     shift_=[shift] (double time UNUSED) { return shift;};
     velocity_=[velocity] (double time UNUSED) {return velocity;};
 }

void LeesEdwardsBoundary::set	(	std::function< double(double)>	shift,
		std::function< double(double)>	velocity,
		Mdouble	left,
		Mdouble	right,
		Mdouble	down,
		Mdouble	up
	)

Sets all boundary properties.

Allows the user to set all the properties of the LeesEdwardsBoundary at once.

Parameters

[in]	velocity	The difference in velocities at which the bottom and to wall move
[in]	left	The (signed) distance between the origin and the left wall
[in]	right	The (signed) distance between the origin and the right wall
[in]	down	The (signed) distance between the origin and the top wall
[in]	up	The (signed) distance between the origin and the bottom wall

Definition at line 39 of file LeesEdwardsBoundary.cc.

References down_, left_, right_, shift_, up_, and velocity_.

 {
     shift_ = shift;
     velocity_ = velocity;
     left_ = left;
     right_ = right;
     down_ = down;
     up_ = up;
 }

void LeesEdwardsBoundary::shiftHorizontalPosition	(	BaseParticle *	p,
		bool	positive
	)

Applies a horizontal shift to the given particle.

Shifts the BaseParticle p in horizontal direction to its 'periodic' position, i.e. over the horizontal length of the boundary.

Parameters

[in]	p	A reference to the BaseParticle that has to be shifted
[in]	positive	A boolean which determines the direction of the shift NB: TRUE if particle is closest to the left boundary wall

Definition at line 141 of file LeesEdwardsBoundary.cc.

References left_, BaseInteractable::move(), and right_.

Referenced by checkBoundaryAfterParticleMoved(), createHorizontalPeriodicParticles(), and createVerticalPeriodicParticles().

 {
     if (positive)
     {
         p->move(Vec3D(right_ - left_, 0.0, 0.0));
     } else
     {
         p->move(Vec3D(left_ - right_, 0.0, 0.0));
     }
 }

void LeesEdwardsBoundary::shiftVerticalPosition	(	BaseParticle *	p,
		bool	positive
	)

Applies a vertical shift to the given particle.

Shifts the BaseParticle p in vertical direction to its 'periodic' position, i.e. over the vertical length of the boundary.

Parameters

[in]	p	A reference to the BaseParticle that has to be shifted
[in]	positive	A boolean which determines the direction of the shift NB: TRUE if particle is closest to the bottom boundary wall

Definition at line 159 of file LeesEdwardsBoundary.cc.

References BaseInteractable::addVelocity(), down_, BaseHandler< T >::getDPMBase(), BaseBoundary::getHandler(), DPMBase::getTime(), BaseInteractable::move(), shift_, up_, and velocity_.

Referenced by checkBoundaryAfterParticleMoved(), and createVerticalPeriodicParticles().

 {
     Mdouble time = getHandler()->getDPMBase()->getTime();
     if (positive)
     {
         p->move(Vec3D(shift_(time), up_ - down_, 0.0));
         p->addVelocity(Vec3D(velocity_(time), 0.0, 0.0));
     } else
     {
         p->move(Vec3D(-shift_(time), down_ - up_, 0.0));
         p->addVelocity(Vec3D(-velocity_(time), 0.0, 0.0));
     }
 }

void LeesEdwardsBoundary::write ( std::ostream & os ) const

virtual

Writes all boundary properties to a stream.

Writes all the properties of the LeesEdwardsBoundary to an std::ostream

Parameters

[out] os The stream to which the parameters are written

Implements BaseBoundary.

Definition at line 68 of file LeesEdwardsBoundary.cc.

References down_, BaseHandler< T >::getDPMBase(), BaseBoundary::getHandler(), DPMBase::getTime(), left_, right_, shift_, up_, velocity_, and BaseBoundary::write().

 {
     BaseBoundary::write(os);
     Mdouble time = getHandler()->getDPMBase()->getTime();
     os<<" left "<<left_<<" right "<<right_<<" down "<<down_<<" up "<<up_<<" shift "<<shift_(time)<<" vel "<<velocity_(time);
 }