This function defines an Archimedes' screw in the z-direction from a (constant) starting point, a (constant) length L, a (constant) radius r, a (constant) number or revelations N and a (constant) rotation speed (rev/s) More...

#include <Screw.h>

Inheritance diagram for Screw:

Public Member Functions
	Screw ()
	Default constructor: make a screw with default parameters. More...

	Screw (const Screw &other)
	Copy constructor, copies another Screw. More...

	Screw (Vec3D start, Mdouble l, Mdouble r, Mdouble n, Mdouble omega, Mdouble thickness, ScrewType screwType=ScrewType::doubleHelix)
	Constructor in which all parameters of the screw are set. More...

	~Screw () override
	Default destructor. More...

Screw *	copy () const final
	Copy this screw and return a pointer to the copy. More...

bool	getDistanceAndNormal (const BaseParticle &P, Mdouble &distance, Vec3D &normal_return) const final
	Compute the distance from the Screw for a given BaseParticle and return if there is a collision. If there is a collision, also return the normal vector of the interaction point. More...

bool	getDistanceAndNormalLabCoordinates (Vec3D position, Mdouble wallInteractionRadius, Mdouble &distance, Vec3D &normal_return) const

void	move_time (Mdouble dt)
	Rotate the Screw for a period dt, so that the offset_ changes with omega_*dt. More...

void	rotate (const Vec3D &angularVelocityDt) override

void	read (std::istream &is) override
	Reads a Screw from an input stream, for example a restart file. More...

void	oldRead (std::istream &is)
	Reads a Screw in the old style from an input stream, for example a restart file old style. More...

void	write (std::ostream &os) const override
	Writes this Screw to an output stream, for example a restart file. More...

std::string	getName () const final
	Returns the name of the object, here the string "Screw". More...

void	writeVTK (VTKContainer &vtk) const override

void	writeVTK (std::string filename) const

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

	BaseWall (const BaseWall &w)
	Copy constructor. More...

	~BaseWall () override
	Default destructor. More...

virtual bool	getDistanceNormalOverlap (const BaseParticle &P, Mdouble &distance, Vec3D &normal_return, Mdouble &overlap) const

virtual bool	getDistanceNormalOverlapSuperquadric (const SuperQuadricParticle &p, Mdouble &distance, Vec3D &normal_return, Mdouble &overlap) const

virtual Vec3D	getFurthestPointSuperQuadric (const Vec3D &normalBodyFixed, const Vec3D &axes, Mdouble eps1, Mdouble eps2) const

virtual void	setHandler (WallHandler *handler)
	A function which sets the WallHandler for this BaseWall. More...

WallHandler *	getHandler () const
	A function which returns the WallHandler that handles this BaseWall. More...

void	setIndSpecies (unsigned int indSpecies) override
	Define the species of this wall using the index of the species in the SpeciesHandler in this DPMBase. More...

void	setSpecies (const ParticleSpecies *species)
	Defines the species of the current wall. More...

bool	isFixed () const override

void	setForceControl (Vec3D forceGoal, Vec3D gainFactor, Vec3D baseVelocity={0, 0, 0})
	Slowly adjusts the force on a wall towards a specified goal, by adjusting (prescribing) the velocity of the wall. More...

virtual bool	isLocal (Vec3D &min, Vec3D &max) const

bool	getLinePlaneIntersect (Vec3D &intersect, const Vec3D &p0, const Vec3D &p1, const Vec3D &n, const Vec3D &p)

bool	isInsideWallVTK (const Vec3D &point, const Vec3D &normal, const Vec3D &position) const

void	projectOntoWallVTK (Vec3D &point0, const Vec3D &point1, const Vec3D &normal, const Vec3D &position) const

void	intersectVTK (std::vector< Vec3D > &points, Vec3D normal, Vec3D position) const

virtual BaseInteraction *	getInteractionWithSuperQuad (SuperQuadricParticle p, unsigned timeStamp, InteractionHandler interactionHandler)

void	getVTK (std::vector< Vec3D > &points, std::vector< std::vector< double >> &triangleStrips)

const Vec3D	getAxis () const

BaseInteraction *	getInteractionWith (BaseParticle p, unsigned timeStamp, InteractionHandler interactionHandler) override
	Returns the interaction between this wall and a given particle, nullptr if there is no interaction. More...

virtual void	actionsOnRestart ()
	No implementation but can be overidden in its derived classes. More...

virtual void	actionsAfterParticleGhostUpdate ()
	No implementation but can be overidden in its derived classes. More...

virtual void	handleParticleAddition (unsigned int id, BaseParticle *p)
	Handles the addition of particles to the particleHandler. More...

virtual void	handleParticleRemoval (unsigned int id)
	Handles the addition of particles to the particleHandler. More...

virtual void	checkInteractions (InteractionHandler *interactionHandler, unsigned int timeStamp)
	Check if all interactions are valid. More...

bool	getVTKVisibility () const

void	setVTKVisibility (bool vtkVisibility)

void	addRenderedWall (BaseWall *w)

BaseWall *	getRenderedWall (size_t i) const

std::vector< BaseWall * >	getRenderedWalls () const

void	removeRenderedWalls ()

void	renderWall (VTKContainer &vtk)

void	addParticlesAtWall (unsigned numElements=50)

void	setVelocityControl (Vec3D forceGoal, Vec3D gainFactor, Vec3D baseVelocity)

virtual void	writeWallDetailsVTK (VTKData &data) const

virtual void	computeWear ()

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

	BaseInteractable (const BaseInteractable &p)
	Copy constructor. More...

	~BaseInteractable () override
	Destructor, it simply destructs the BaseInteractable and all the objects it contains. More...

unsigned int	getIndSpecies () const
	Returns the index of the species associated with the interactable object. More...

const ParticleSpecies *	getSpecies () const
	Returns a pointer to the species of this BaseInteractable. More...

void	setSpecies (const ParticleSpecies *species)
	Sets the species of this BaseInteractable. More...

const Vec3D &	getForce () const
	Returns the force on this BaseInteractable. More...

const Vec3D &	getTorque () const
	Returns the torque on this BaseInteractable. More...

void	setForce (const Vec3D &force)
	Sets the force on this BaseInteractable. More...

void	setTorque (const Vec3D &torque)
	Sets the torque on this BaseInteractable. More...

void	addForce (const Vec3D &addForce)
	Adds an amount to the force on this BaseInteractable. More...

void	addTorque (const Vec3D &addTorque)
	Adds an amount to the torque on this BaseInteractable. More...

virtual void	resetForceTorque (int numberOfOMPthreads)

void	sumForceTorqueOMP ()

const Vec3D &	getPosition () const
	Returns the position of this BaseInteractable. More...

const Quaternion &	getOrientation () const
	Returns the orientation of this BaseInteractable. More...

virtual void	setPosition (const Vec3D &position)
	Sets the position of this BaseInteractable. More...

void	setOrientationViaNormal (Vec3D normal)
	Sets the orientation of this BaseInteractable by defining the vector that results from the rotation of the (1,0,0) vector. More...

void	setOrientationViaEuler (Vec3D eulerAngle)
	Sets the orientation of this BaseInteractable by defining the euler angles. More...

virtual void	setOrientation (const Quaternion &orientation)
	Sets the orientation of this BaseInteractable. More...

virtual void	move (const Vec3D &move)
	Moves this BaseInteractable by adding an amount to the position. More...

const std::vector< BaseInteraction * > &	getInteractions () const
	Returns a list of interactions which belong to this interactable. More...

void	addInteraction (BaseInteraction *I)
	Adds an interaction to this BaseInteractable. More...

bool	removeInteraction (BaseInteraction *I)
	Removes an interaction from this BaseInteractable. More...

void	copyInteractionsForPeriodicParticles (const BaseInteractable &p)
	Copies interactions to this BaseInteractable whenever a periodic copy made. More...

void	setVelocity (const Vec3D &velocity)
	set the velocity of the BaseInteractable. More...

void	setAngularVelocity (const Vec3D &angularVelocity)
	set the angular velocity of the BaseInteractble. More...

void	addVelocity (const Vec3D &velocity)
	adds an increment to the velocity. More...

void	addAngularVelocity (const Vec3D &angularVelocity)
	add an increment to the angular velocity. More...

virtual const Vec3D &	getVelocity () const
	Returns the velocity of this interactable. More...

virtual const Vec3D &	getAngularVelocity () const
	Returns the angular velocity of this interactable. More...

void	setPrescribedPosition (const std::function< Vec3D(double)> &prescribedPosition)
	Allows the position of an infinite mass interactable to be prescribed. More...

void	applyPrescribedPosition (double time)
	Computes the position from the user defined prescribed position function. More...

void	setPrescribedVelocity (const std::function< Vec3D(double)> &prescribedVelocity)
	Allows the velocity of an infinite mass interactable to be prescribed. More...

void	applyPrescribedVelocity (double time)
	Computes the velocity from the user defined prescribed velocity function. More...

void	setPrescribedOrientation (const std::function< Quaternion(double)> &prescribedOrientation)
	Allows the orientation of the infinite mass interactbale to be prescribed. More...

void	applyPrescribedOrientation (double time)
	Computes the orientation from the user defined prescribed orientation function. More...

void	setPrescribedAngularVelocity (const std::function< Vec3D(double)> &prescribedAngularVelocity)
	Allows the angular velocity of the infinite mass interactable to be prescribed. More...

void	applyPrescribedAngularVelocity (double time)
	Computes the angular velocity from the user defined prescribed angular velocity. More...

virtual const Vec3D	getVelocityAtContact (const Vec3D &contact) const
	Returns the velocity at the contact point, use by many force laws. More...

void	integrateBeforeForceComputation (double time, double timeStep)
	This is part of integrate routine for objects with infinite mass. More...

void	integrateAfterForceComputation (double time, double timeStep)
	This is part of the integration routine for objects with infinite mass. More...

virtual Mdouble	getInvMass () const

virtual Mdouble	getCurvature (const Vec3D &labFixedCoordinates) const

virtual bool	isFaceContact (const Vec3D &normal) const

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

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

virtual	~BaseObject ()=default
	virtual destructor More...

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

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

void	setId (unsigned long 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...

void	setGroupId (unsigned groupId)

unsigned	getGroupId () const

Private Attributes
Vec3D	start_
	The centre of the lower end of the screw. More...

Mdouble	l_
	The length of the Screw. More...

Mdouble	maxR_
	The outer radius of the Screw. More...

Mdouble	n_
	The number of revelations. More...

Mdouble	omega_
	Rotation speed in rev/s. More...

Mdouble	offset_
	The angle that describes how much the Screw has turned, going from 0 to 1 for a rotation. More...

Mdouble	thickness_
	The thickness of the Screw. More...

ScrewType	screwType_
	Single or double helix screw. More...

Additional Inherited Members
Static Public Member Functions inherited from BaseWall
static void	addToVTK (const std::vector< Vec3D > &points, VTKContainer &vtk)
	Takes the points provided and adds a triangle strip connecting these points to the vtk container. More...

Detailed Description

This function defines an Archimedes' screw in the z-direction from a (constant) starting point, a (constant) length L, a (constant) radius r, a (constant) number or revelations N and a (constant) rotation speed (rev/s)

q is a new coordinate going from 0 to 1 and t is the time, x=xs+r*cos(2*pi*(offset+N*q)), y=ys+r*sin(2*pi*(offset+N*q)), z=zs+q*L

Todo:: IFCD: Can these details about class Screw be made more clear? I don't understand them.

Constructor & Destructor Documentation

◆ Screw() [1/3]

Screw::Screw ( )

Default constructor: make a screw with default parameters.

Make a Screw which is centered in the origin, has a length of 1, one revelation, a radius of 1, turns with 1 revelation per second, is infinitely thin and starts at its normal initial point.

 {
     start_.setZero();
     l_ = 1.0;
     maxR_ = 1.0;
     n_ = 1.0;
     omega_ = 1.0;
     offset_ = 0.0;
     thickness_ = 0.0;
     screwType_ = ScrewType::doubleHelix;
     setOrientationViaNormal({0, 0, 1});//default screw is in z-direction
     logger(DEBUG, "Screw() constructor finished.");
 }

References DEBUG, doubleHelix, l_, logger, maxR_, n_, offset_, omega_, screwType_, BaseInteractable::setOrientationViaNormal(), Vec3D::setZero(), start_, and thickness_.

Referenced by copy().

◆ Screw() [2/3]

Screw::Screw ( const Screw & other )

Copy constructor, copies another Screw.

Parameters

[in] other The Screw that has to be copied.

         : BaseWall(other)
 {
     start_ = other.start_;
     l_ = other.l_;
     maxR_ = other.maxR_;
     n_ = other.n_;
     omega_ = other.omega_;
     thickness_ = other.thickness_;
     offset_ = other.offset_;
     screwType_ = other.screwType_;
     logger(DEBUG, "Screw(const Screw&) copy constructor finished.");
 }

References DEBUG, l_, logger, maxR_, n_, offset_, omega_, screwType_, start_, and thickness_.

◆ Screw() [3/3]

Screw::Screw	(	Vec3D	start,
		Mdouble	l,
		Mdouble	r,
		Mdouble	n,
		Mdouble	omega,
		Mdouble	thickness,
		ScrewType	screwType = `ScrewType::doubleHelix`
	)

Constructor in which all parameters of the screw are set.

Parameters

[in]	start	A Vec3D which denotes the centre of the lower end of the Screw.
[in]	l	The length of the Screw, must be positive.
[in]	r	The radius of the Screw, must be positive.
[in]	n	The number of revelations of the Screw, must be positive.
[in]	omega	The rotation speed of the Screw in rev/s.
[in]	thickness	The thickness of the Screw, must be non-negative.

Make a Screw by assigning all input parameters to the data-members of this class, and setting the offset_ to 0.

 {
     start_ = start;
     l_ = l;
     maxR_ = r;
     n_ = n;
     omega_ = omega;
     thickness_ = thickness;
     offset_ = 0.0;
     screwType_ = screwType;
     logger(DEBUG, "Screw(Vec3D, Mdouble, Mdouble, Mdouble, Mdouble, Mdouble) constructor finished.");
 }

References DEBUG, l_, logger, maxR_, n, n_, offset_, omega_, screwType_, start_, and thickness_.

◆ ~Screw()

Screw::~Screw ( )

override

Default destructor.

 {
     logger(DEBUG, "~Screw() finished, destroyed the Screw.");
 }

References DEBUG, and logger.

Member Function Documentation

◆ copy()

Screw * Screw::copy ( ) const

finalvirtual

Copy this screw and return a pointer to the copy.

Returns: A pointer to a copy of this Screw.

Implements BaseWall.

 {
     return new Screw(*this);
 }

References Screw().

◆ getDistanceAndNormal()

bool Screw::getDistanceAndNormal	(	const BaseParticle &	P,
		Mdouble &	distance,
		Vec3D &	normal_return
	)		const

finalvirtual

Compute the distance from the Screw for a given BaseParticle and return if there is a collision. If there is a collision, also return the normal vector of the interaction point.

Todo:: do this for all walls

Implements BaseWall.

 {
     //transform coordinates into position-orientation frame
     Vec3D position = P.getPosition() - getPosition();
     getOrientation().rotateBack(position);
     BaseSpecies* s = getHandler()->getDPMBase()->speciesHandler.getMixedObject(P.getSpecies(), getSpecies());
     if (getDistanceAndNormalLabCoordinates(position, P.getRadius() + s->getInteractionDistance(), distance,
                                            normal_return))
     {
         getOrientation().rotate(normal_return);
         return true;
     }
     else
     {
         return false;
     }
 }

References getDistanceAndNormalLabCoordinates(), BaseHandler< T >::getDPMBase(), BaseWall::getHandler(), BaseSpecies::getInteractionDistance(), SpeciesHandler::getMixedObject(), BaseInteractable::getOrientation(), BaseInteractable::getPosition(), BaseInteractable::getSpecies(), Global_Physical_Variables::P, Quaternion::rotate(), Quaternion::rotateBack(), and DPMBase::speciesHandler.

◆ getDistanceAndNormalLabCoordinates()

bool Screw::getDistanceAndNormalLabCoordinates	(	Vec3D	position,
		Mdouble	wallInteractionRadius,
		Mdouble &	distance,
		Vec3D &	normal_return
	)		const

Parameters

[in]	p	BaseParticle we want to calculate the distance and whether it collided of.
[out]	distance	The distance of the BaseParticle to this wall.
[out]	normal_return	If there was a collision, the normal vector to this wall will be placed here.

Returns: A boolean which says whether or not there was a collision.

This function computes whether or not there is a collision between a given BaseParticle and this Screw. If there is a collision, this function also computes the distance between the BaseParticle and Screw and the normal of the IntersectionOfWalls at the intersection point.

Todo:: Make this function readable and explain the steps in the details.

 {
     // compute the square of the radial distance (in yz-plane) between particle and screw.
     const Mdouble RSquared = square(position.Y - start_.Y) + square(position.Z - start_.Z);
     const Mdouble X = position.X - start_.X;
  
     //first do a simple check if particle is within the cylindrical hull of the screw
     if (RSquared > square(maxR_ + wallInteractionRadius + thickness_)
         || X > l_ + wallInteractionRadius + thickness_
         || X < -wallInteractionRadius - thickness_)
     {
         return false;
     }
     
     //else compute radial distance, and angle in yz-plane
     const Mdouble R = sqrt(RSquared);
     const Mdouble A = atan2(position.Z - start_.Z, position.Y - start_.Y);
     
     //after subtracting the start position and transforming the particle position from (XYZ) into (XRA)
     //coordinates, we compute the distance to the wall at, located at (r,a,z)=(q*L,r,2*pi*(offset+N*q+k/2)), 0<q<1.
     
     //To find the contact point we have to minimize (with respect to r and q)
     //distance^2=(x-x0-r*cos(2*pi*(offset+N*q)))^2+(y-y0-r*sin(2*pi*(offset+N*q)))^2+(z-z0-q*L)^2
     //Using polar coordinates (i.e. x-x0=R*cos(A), y-y0=R*sin(A) and Z=z-z0)
     //distance^2=R^2+r^2-2*R*r*cos(A-2*pi*(offset+N*q))+(Z-q*L)^2
     
     //Assumption: d(distance)/dr=0 at minDistance (should there be also a q-derivative?)
     //Differentiate with respect to r and solve for zero:
     //0=2*r-2*R*cos(A-2*pi*(offset+N*q)
     //r=R*cos(A-2*pi*(offset+N*q))
     
     //Substitue back
     //distance^2=R^2+R^2*cos^2(A-2*pi*(offset+N*q))-2*R^2*cos^2(A-2*pi*(offset+N*q))+(Z-q*L)^2
     //distance^2=R^2*sin^2(A-2*pi*(offset+N*q))+(Z-q*L)^2
     
     //So we have to minimize:
     //distance^2=R^2*sin^2(A-2*pi*(offset+N*q))^2 + (Z-q*L)^2 = f(q)
     //f'(q)=(-2*pi*N)*R^2*sin(2*A-4*pi*(offset+N*q)) + 2*L*(Z-q*L)    (D[Sin[x]^2,x]=Sin[2x])
     //f''(q)=(4*pi^2*N^2)*R^2*cos(2*A-4*pi*(offset+N*q)) - 2*L*L
     //For this we use the Euler algoritm
     
     Mdouble q; //Current guess
     Mdouble dd; //Derivative at current guess
     Mdouble ddd; //Second derivative at current guess
  
     //Set initial q to the closest position on the screw with the same angle as A
     //The initial guess will be in the minimum of the sin closest to q0
     //Minima of the sin are at
     //A-2*pi*(offset+N*q)=k*pi (k=integer)
     //q=A/(2*pi*N)-k/(2*N)-offset/N (k=integer)
     {
         const Mdouble q0 = X / l_; //assume closest point q0 is at same z-location as the particle
         const Mdouble k = round(A / constants::pi - 2.0 * (offset_ + n_ * q0)); // k: |A-a(q0)-k*pi|=min
         q = A / (2.0 * constants::pi * n_) - k / (2.0 * n_) - offset_ / n_; // q: a(q)=A
     }
     
     //Now apply Newton's method
     unsigned count = 0;
     const unsigned maxCount = 30;
     do
     {
         Mdouble arg = 2.0 * A - 4.0 * constants::pi * (n_ * q + offset_);
         dd = -2.0 * constants::pi * n_ * RSquared * sin(arg) - 2.0 * l_ * (X - q * l_);
         ddd = 8.0 * constants::sqr_pi * n_ * n_ * RSquared * cos(arg) + 2.0 * l_ * l_;
         q -= dd / ddd;
         if(++count>maxCount) {
             logger(WARN,"Screw % contact detection did not converge (err=%); continuing with approximate contact point",getId(),fabs(dd/ddd));
             break;
         }
     } while (fabs(dd / ddd) > 5e-14);
     
     //Calculate r
     Mdouble r = R * cos(2.0 * constants::pi * (offset_ + n_ * q) - A);
     
     //If the particle touches the single screw center
     if (screwType_==ScrewType::singleHelix && r>0) {
         distance = R-thickness_;
         if (distance>wallInteractionRadius) {
             return false;
         } else {
             normal_return = Vec3D(0,-position.Y/R,-position.Z/R);
             return true;
         }
     }
  
     //Check if the location is actually on the screw:
     //First posibility is that the radius is too large:
     Mdouble distanceSquared = 0;
     if (fabs(r) > maxR_) //Left boundary of the coil
     {
         r = mathsFunc::sign(r) * maxR_;
         distanceSquared = mathsFunc::square(R-maxR_);
         count = 0;
         //This case reduces to the coil problem
         do
         {
             dd = -4.0 * R * r * constants::pi * n_ * sin(A - 2.0 * constants::pi * (n_ * q + offset_)) -
                  2.0 * l_ * (X - q * l_);
             ddd = 8.0 * R * r * constants::sqr_pi * n_ * n_ * cos(A - 2.0 * constants::pi * (n_ * q + offset_)) +
                   2.0 * l_ * l_;
             q -= dd / ddd;
             if(++count>maxCount) {
                 logger(WARN,"Screw % contact detection at left boundary did not converge (err=%); continuing with approximate contact point",getId(),fabs(dd/ddd));
                 break;
             }
         } while (fabs(dd / ddd) > 1e-13);
     }
     //Second possibility is that it occured before the start of after the end
     if (q < 0)
     {
         q = 0;
         r = R * cos(A - 2.0 * constants::pi * (offset_ + q * n_));
         if (fabs(r) > maxR_)
         {
             r = mathsFunc::sign(r) * maxR_;
         }
     }
     else if (q > 1)
     {
         q = 1;
         r = R * cos(A - 2.0 * constants::pi * (offset_ + q * n_));
         if (fabs(r) > maxR_)
         {
             r = mathsFunc::sign(r) * maxR_;
         }
     }
     
     //compute squared distance between particle and contact point
     distanceSquared += square(X - q * l_) + square(R*sin(A - 2 * constants::pi * (offset_ + n_ * q)));
     
     //If distance is too large there is no contact
     if (distanceSquared >= square(wallInteractionRadius + thickness_))
     {
         return false;
     }
     
     //Else
     Vec3D ContactPoint;
     distance = sqrt(distanceSquared) - thickness_;
     ContactPoint.Y = start_.Y + r * cos(2.0 * constants::pi * (offset_ + n_ * q));
     ContactPoint.Z = start_.Z + r * sin(2.0 * constants::pi * (offset_ + n_ * q));
     ContactPoint.X = start_.X + q * l_;
     normal_return = (ContactPoint - position);
     normal_return.normalise();
     return true;
 }

References A, mathsFunc::cos(), BaseObject::getId(), l_, logger, maxR_, n_, Vec3D::normalise(), offset_, constants::pi, R, helpers::round(), screwType_, mathsFunc::sign(), mathsFunc::sin(), singleHelix, constants::sqr_pi, mathsFunc::square(), start_, thickness_, WARN, Vec3D::X, X, Vec3D::Y, and Vec3D::Z.

Referenced by getDistanceAndNormal().

◆ getName()

std::string Screw::getName ( ) const

finalvirtual

Returns the name of the object, here the string "Screw".

Returns: The string "Screw".

Implements BaseObject.

 {
     return "Screw";
 }

Referenced by writeVTK().

◆ move_time()

void Screw::move_time ( Mdouble dt )

Rotate the Screw for a period dt, so that the offset_ changes with omega_*dt.

Parameters

[in] dt The time for which the Screw has to be turned.

 {
     //offset_ += omega_ * dt;
 }

◆ oldRead()

void Screw::oldRead ( std::istream & is )

Reads a Screw in the old style from an input stream, for example a restart file old style.

Parameters

[in,out] is Input stream from which the Screw must be read.

Read the Screw in old style, please note that the thickness is not read in this function, so it has either to be set manually or it is 0.0 from the default constructor.

 {
     std::string dummy;
     is >> dummy >> start_
        >> dummy >> l_
        >> dummy >> maxR_
        >> dummy >> n_
        >> dummy >> omega_
        >> dummy >> offset_;
 }

References l_, maxR_, n_, offset_, omega_, and start_.

◆ read()

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

overridevirtual

Reads a Screw from an input stream, for example a restart file.

Parameters

[in,out] is Input stream from which the Screw must be read.

Reimplemented from BaseWall.

 {
     BaseWall::read(is);
     std::string dummy;
     unsigned screwType;
     is >> dummy >> start_
        >> dummy >> l_
        >> dummy >> maxR_
        >> dummy >> n_
        >> dummy >> omega_
        >> dummy >> thickness_
        >> dummy >> offset_
        >> dummy >> screwType;
     screwType_ = static_cast<ScrewType>(screwType);
 }

References l_, maxR_, n_, offset_, omega_, BaseWall::read(), screwType_, start_, and thickness_.

◆ rotate()

void Screw::rotate ( const Vec3D & angularVelocityDt )

overridevirtual

Todo:: the move and rotate functions should only pass the time step, as teh velocity can be accessed directly by the object

Parameters

angularVelocityDt

Reimplemented from BaseInteractable.

 {
     BaseInteractable::rotate(angularVelocityDt);
     offset_ += omega_ * getHandler()->getDPMBase()->getTimeStep();
 }

References BaseHandler< T >::getDPMBase(), BaseWall::getHandler(), DPMBase::getTimeStep(), offset_, omega_, and BaseInteractable::rotate().

◆ write()

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

overridevirtual

Writes this Screw to an output stream, for example a restart file.

Parameters

[in,out] os Output stream to which the Screw must be written.

Reimplemented from BaseWall.

 {
     BaseWall::write(os);
     os << " start " << start_
        << " Length " << l_
        << " Radius " << maxR_
        << " Revolutions " << n_
        << " Omega " << omega_
        << " Thickness " << thickness_
        << " Offset " << offset_
        << " ScrewType " << static_cast<unsigned>(screwType_);
 }

References l_, maxR_, n_, offset_, omega_, screwType_, start_, thickness_, and BaseWall::write().

◆ writeVTK() [1/2]

void Screw::writeVTK ( std::string filename ) const

 {
     VTKContainer vtk;
     writeVTK(vtk);
     
     std::stringstream file;
     file << "# vtk DataFile Version 2.0\n"
          << getName() << "\n"
                          "ASCII\n"
                          "DATASET UNSTRUCTURED_GRID\n"
                          "POINTS " << vtk.points.size() << " double\n";
     for (const auto& vertex : vtk.points)
         file << vertex << '\n';
     file << "\nCELLS " << vtk.triangleStrips.size() << ' ' << 4 * vtk.triangleStrips.size() << "\n";
     for (const auto& face : vtk.triangleStrips)
         file << "3 " << face[0] << ' ' << face[1] << ' ' << face[2] << '\n';
     file << "\nCELL_TYPES " << vtk.triangleStrips.size() << "\n";
     for (const auto& face UNUSED : vtk.triangleStrips)
         file << "5\n";
     helpers::writeToFile(filename, file.str());
 }

References getName(), VTKContainer::points, VTKContainer::triangleStrips, UNUSED, helpers::writeToFile(), and writeVTK().

◆ writeVTK() [2/2]

void Screw::writeVTK ( VTKContainer & vtk ) const

overridevirtual

adds extra information to the points and triangleStrips vectors needed to plot the wall in vtk format

Parameters

points	Coordinates of the vertices of the triangulated surfaces (in the VTK file this is called POINTS)
triangleStrips	Indices of three vertices forming one triangulated surface (in the VTK file this is called CELL)

Reimplemented from BaseWall.

 {
     //number of points in radial direction (for one side of the screw)
     unsigned nr = 5;
     //number of points in axial direction
     unsigned nz = static_cast<unsigned int>(99 * fabs(n_));
     
     unsigned long nPoints = vtk.points.size();
     Vec3D contactPoint;
     // either one or two helices
     for (Mdouble offset = offset_; offset<=offset_+(screwType_==ScrewType::doubleHelix?0.5:0); offset+=0.5)
     {
         for (unsigned iz = 0; iz < nz; iz++)
         {
             for (unsigned ir = 0; ir < nr; ir++)
             {
                 double q = (double) iz / nz;
                 double r = (double) ir / (nr - 1) * maxR_;
                 contactPoint.Y = start_.Y - r * cos(2.0 * constants::pi * (offset + n_ * q));
                 contactPoint.Z = start_.Z - r * sin(2.0 * constants::pi * (offset + n_ * q));
                 contactPoint.X = start_.X + q * l_ - thickness_;
                 getOrientation().rotate(contactPoint);
                 contactPoint += getPosition();
                 vtk.points.push_back(contactPoint);
             }
             for (unsigned ir = 0; ir < nr; ir++)
             {
                 double q = (double) iz / nz;
                 double r = (double) (nr - 1 - ir) / (nr - 1) * maxR_;
                 contactPoint.Y = start_.Y - r * cos(2.0 * constants::pi * (offset + n_ * q));
                 contactPoint.Z = start_.Z - r * sin(2.0 * constants::pi * (offset + n_ * q));
                 contactPoint.X = start_.X + q * l_ + thickness_;
                 getOrientation().rotate(contactPoint);
                 contactPoint += getPosition();
                 vtk.points.push_back(contactPoint);
             }
         }
     }
     
     for (unsigned iz = 0; iz < (screwType_==ScrewType::doubleHelix?2:1)*nz-1; iz++)
     {
         //skip step that would connect the two screw parts
         if (iz==nz-1) ++iz;
         std::vector<double> cell;
         cell.reserve(2 * nr);
         for (unsigned ir = 0; ir < 2*nr; ir++)
         {
             cell.push_back(nPoints + ir + 2*iz * nr);
             cell.push_back(nPoints + ir + 2*(iz + 1) * nr);
         }
         vtk.triangleStrips.push_back(cell);
     }
 }