DropletBoundary Class Reference

Supplies a 'constant heat flux' to a cuboidal region (specified by two corner points) by adding a random velocity at each time step to each particle therein, increasing the granular temperature (velocity variance). More...

#include <DropletBoundary.h>

Inheritance diagram for DropletBoundary:

Classes
struct	Droplet

Public Member Functions
	DropletBoundary ()
	DropletBoundary (const DropletBoundary &other)
	~DropletBoundary () override
DropletBoundary *	copy () const override
	Used to create a copy of the object NB: purely virtual function. More...
std::string	getName () const override
	A purely virtual function. More...
void	checkBoundaryAfterParticlesMove (ParticleHandler &pH) override
	Runs at the end of each time step. More...
void	read (std::istream &is) override
	Reads some boundary properties from an std::istream. More...
void	write (std::ostream &os) const override
	Writes the boundary properties to an std::ostream. More...
void	setGenerateDroplets (std::function< void(DropletBoundary &)> generateDroplets)
void	writeVTK (std::fstream &file) override
void	setRemoveDropletsAtWalls (bool removeDroplets)
void	setDropletSpecies (const ParticleSpecies *species)
void	actionsBeforeTimeLoop () override
	Virtual function that does something after DPMBase::setupInitialConditions but before the first time step. More...
Public Member Functions inherited from BaseBoundary
	BaseBoundary ()
	default constructor. More...
	BaseBoundary (const BaseBoundary &b)
	copy constructor More...
	~BaseBoundary () override
	destructor More...
virtual void	createPeriodicParticle (BaseParticle *p UNUSED, ParticleHandler &pH UNUSED)
	Creates a periodic particle in case of periodic boundaries in serial build. More...
virtual void	createPeriodicParticles (ParticleHandler &pH UNUSED)
	Creates periodic copies of given particle in case of periodic boundaries. More...
virtual void	checkBoundaryBeforeTimeStep (DPMBase *md)
	Virtual function that does things before each time step. More...
virtual void	modifyGhostAfterCreation (BaseParticle *particle, int i)
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
	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

Public Attributes
std::vector< Droplet >	droplets_
double	dropletVolume = 0
double	absorbedVolume = 0
double	lostVolume = 0
unsigned	checkCount = 3

Private Attributes
std::function< void(DropletBoundary &)>	generateDroplets_ = [] (DropletBoundary&) {}
bool	removeDropletsAtWalls_ = true
const ParticleSpecies *	dropletSpecies_ = nullptr

Detailed Description

Supplies a 'constant heat flux' to a cuboidal region (specified by two corner points) by adding a random velocity at each time step to each particle therein, increasing the granular temperature (velocity variance).

Note, you need to create a species for the droplets that has liquidVolumeMax-0, or the contact happens at a non-zero distance

Constructor & Destructor Documentation

DropletBoundary() [1/2]

DropletBoundary::DropletBoundary ( )

inline

{}

Referenced by copy().

DropletBoundary() [2/2]

DropletBoundary::DropletBoundary ( const DropletBoundary &  other )

inline

                                                  {
        droplets_ = other.droplets_;
        generateDroplets_ = other.generateDroplets_;
        removeDropletsAtWalls_ = other.removeDropletsAtWalls_;
        dropletSpecies_ = other.dropletSpecies_;
    }

References droplets_, dropletSpecies_, generateDroplets_, and removeDropletsAtWalls_.

~DropletBoundary()

DropletBoundary::~DropletBoundary ( )

inlineoverride

                                {
        logger(VERBOSE, "A DropletBoundary has been destroyed.");
    }

References logger, and VERBOSE.

Member Function Documentation

actionsBeforeTimeLoop()

void DropletBoundary::actionsBeforeTimeLoop ( )

inlineoverridevirtual

Virtual function that does something after DPMBase::setupInitialConditions but before the first time step.

Can be used to perform actions before the time loop, but after setupInitialConditions.

Reimplemented from BaseBoundary.

    {
        // When no droplet species were set, use the last species from the handler.
        // This is fine for when the droplets are removed at the walls, if not, a warning is shown.
        if (!dropletSpecies_)
        {
            dropletSpecies_ = getHandler()->getDPMBase()->speciesHandler.getLastObject();
            if (!removeDropletsAtWalls_)
                logger(WARN, "DropletBoundary: Droplets should repel from wall, but no droplet species was set. Using last species from the species handler instead.");
        }
 
        // When droplets should repel from the wall, it requires to be checked every time step.
        if (!removeDropletsAtWalls_)
            checkCount = 1;
    }

References checkCount, dropletSpecies_, BaseHandler< T >::getDPMBase(), BaseBoundary::getHandler(), BaseHandler< T >::getLastObject(), logger, removeDropletsAtWalls_, DPMBase::speciesHandler, and WARN.

checkBoundaryAfterParticlesMove()

void DropletBoundary::checkBoundaryAfterParticlesMove ( ParticleHandler &  pH )

overridevirtual

Runs at the end of each time step.

Reimplemented from BaseBoundary.

{
    MercuryBase* dpm = dynamic_cast<MercuryBase*>(getHandler()->getDPMBase());
    logger.assert_always(dpm,"You can only run DropletBoundary with Mercury2D or Mercury3D, not DPMBase");
    // generate new droplets
    generateDroplets_(*this);
    // integrate Newtons equation of motion
    Vec3D g = dpm->getGravity();
    double dt = dpm->getTimeStep();
    for (auto& d : droplets_) {
        Mdouble m = dropletSpecies_->getMassFromRadius(d.radius);
        d.velocity += dt * (d.force + m * g) / m;
        d.force.setZero();
        d.position += dt*d.velocity;
    }
    // check for interaction with particles; this is costly, so we only do iit every 50 time steps
    if (dpm->getNumberOfTimeSteps()%checkCount==0) {
        LiquidFilmParticle p;
        p.setSpecies(dropletSpecies_);
        for (auto &d : droplets_) {
            p.setPosition(d.position);
            p.setVelocity(d.velocity);
            p.setRadius(d.radius);
            auto q = dpm->hGridFindParticleContacts(&p);
            if (q.size() > 0) {
                double liquidVolume = std::pow(2.0 * d.radius, 3) * constants::pi / 6.0;
                for (auto particle : q) {
                    // should that be a static cast?
                    auto lfp = static_cast<LiquidFilmParticle *>(particle);
                    lfp->addLiquidVolume(liquidVolume/q.size());
                }
                absorbedVolume += liquidVolume;
                dropletVolume -= liquidVolume;
                d.radius = 0;
            }
            // check for interactions with walls
            for (BaseWall* w : dpm->wallHandler) {
                //Checks if the particle is interacting with the current wall
                BaseInteraction* i = w->getInteractionWith(&p, dpm->getNumberOfTimeSteps() + 1, &dpm->interactionHandler);
                // if there is a wall interacting with the droplet
                if (i != nullptr) {
                    if (removeDropletsAtWalls_) {
                        //set droplet radius to zero
                        double liquidVolume = std::pow(2.0 * d.radius, 3) * constants::pi / 6.0;
                        lostVolume += liquidVolume;
                        dropletVolume -= liquidVolume;
                        d.radius = 0;
                    } else {
                        // For some reason the species have to be set here, otherwise the force is always 0.
                        i->setSpecies(dropletSpecies_);
                        i->computeForce();
                        d.force += i->getForce();
                    }
                }
            }
        }
        // erase all droplets of radius 0
        droplets_.erase(std::remove_if(droplets_.begin(), droplets_.end(),
                                       [](const Droplet &d) { return d.radius == 0; }), droplets_.end());
    }
}

References absorbedVolume, LiquidFilm< Particle >::addLiquidVolume(), checkCount, droplets_, dropletSpecies_, dropletVolume, generateDroplets_, BaseHandler< T >::getDPMBase(), DPMBase::getGravity(), BaseBoundary::getHandler(), BaseWall::getInteractionWith(), ParticleSpecies::getMassFromRadius(), DPMBase::getNumberOfTimeSteps(), DPMBase::getTimeStep(), MercuryBase::hGridFindParticleContacts(), constants::i, DPMBase::interactionHandler, logger, lostVolume, constants::pi, removeDropletsAtWalls_, and DPMBase::wallHandler.

copy()

DropletBoundary* DropletBoundary::copy ( ) const

inlineoverridevirtual

Used to create a copy of the object NB: purely virtual function.

Implements BaseBoundary.

                                           {
        return new DropletBoundary(*this);
    }

References DropletBoundary().

getName()

std::string DropletBoundary::getName ( ) const

inlineoverridevirtual

A purely virtual function.

Implements BaseObject.

                                       {
        return "DropletBoundary";
    }

read()

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

overridevirtual

Reads some boundary properties from an std::istream.

Reads a number of boundary properties from the given std::istream.

Parameters

[in,out]

is

the istream

Implements BaseBoundary.

{
    BaseBoundary::read(is);
    std::string dummy;
    size_t n;
    Vec3D position, velocity;
    double radius;
    is >> dummy >> checkCount;
    is >> dummy >> n;
    droplets_.reserve(n);
    droplets_.resize(0);
    for (int i = 0; i < n; ++i) {
        is >> position >> velocity >> radius;
        droplets_.emplace_back(Droplet{position,velocity,radius});
    }
}

References checkCount, droplets_, constants::i, n, and BaseBoundary::read().

setDropletSpecies()

void DropletBoundary::setDropletSpecies ( const ParticleSpecies *  species )

inline

                                                           {
        dropletSpecies_ = species;
    }

References dropletSpecies_.

setGenerateDroplets()

void DropletBoundary::setGenerateDroplets ( std::function< void(DropletBoundary &)>  generateDroplets )

inline

                                                                                   {
        generateDroplets_=generateDroplets;
    }

References generateDroplets_.

Referenced by main(), NozzleDemo::setupInitialConditions(), and NozzleSelfTest::setupInitialConditions().

setRemoveDropletsAtWalls()

void DropletBoundary::setRemoveDropletsAtWalls ( bool  removeDroplets )

inline

                                                       {
        removeDropletsAtWalls_ = removeDroplets;
    }

References removeDropletsAtWalls_.

write()

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

overridevirtual

Writes the boundary properties to an std::ostream.

Writes the boundary properties to an std::ostream.

Parameters

[out]

os

the ostream the properties are to be written to.

Implements BaseBoundary.

{
    BaseBoundary::write(os);
    os << " checkCount " << checkCount;
    os << " n " << droplets_.size();
    for (auto& d : droplets_) {
        os << " " << d.position;
        os << " " << d.velocity;
        os << " " << d.radius;
    }
}

References checkCount, droplets_, and BaseBoundary::write().

writeVTK()

void DropletBoundary::writeVTK ( std::fstream &  file )

overridevirtual

Reimplemented from BaseBoundary.

                                               {
    file << "<Piece NumberOfPoints=\"" << droplets_.size() << "\" NumberOfCells=\"" << 0 << "\">\n";
    file << "<Points>\n";
    file << "  <DataArray type=\"Float32\" Name=\"Position\" NumberOfComponents=\"3\" format=\"ascii\">\n";
    for (const auto& d : droplets_) file << '\t' << (float)d.position.X << ' ' << (float)d.position.Y << ' ' << (float)d.position.Z << '\n';
    file << "  </DataArray>\n";
    file << "</Points>\n";
    file << "<PointData  Vectors=\"vector\">\n";
    file << "  <DataArray type=\"Float32\" Name=\"Velocity\" NumberOfComponents=\"3\" format=\"ascii\">\n";
    for (const auto& d : droplets_) file << '\t' << (float)d.velocity.X << ' ' << (float)d.velocity.Y << ' ' << (float)d.velocity.Z << '\n';
    file << "  </DataArray>\n";
    file << "  <DataArray type=\"Float32\" Name=\"Radius\" format=\"ascii\">\n";
    for (const auto& d : droplets_) file << '\t' << (float)d.radius << '\n';
    file << "  </DataArray>\n";
    file << "</PointData>\n";
}

References droplets_.

Member Data Documentation

absorbedVolume

double DropletBoundary::absorbedVolume = 0

Referenced by checkBoundaryAfterParticlesMove().

checkCount

unsigned DropletBoundary::checkCount = 3

Referenced by actionsBeforeTimeLoop(), checkBoundaryAfterParticlesMove(), read(), and write().

droplets_

std::vector<Droplet> DropletBoundary::droplets_

Referenced by checkBoundaryAfterParticlesMove(), DropletBoundary(), main(), NozzleDemo::printTime(), NozzleSelfTest::printTime(), read(), NozzleDemo::setupInitialConditions(), NozzleSelfTest::setupInitialConditions(), write(), and writeVTK().

dropletSpecies_

const ParticleSpecies* DropletBoundary::dropletSpecies_ = nullptr

private

Referenced by actionsBeforeTimeLoop(), checkBoundaryAfterParticlesMove(), DropletBoundary(), and setDropletSpecies().

dropletVolume

double DropletBoundary::dropletVolume = 0

Referenced by checkBoundaryAfterParticlesMove().

generateDroplets_

std::function<void(DropletBoundary&)> DropletBoundary::generateDroplets_ = [] (DropletBoundary&) {}

private

Referenced by checkBoundaryAfterParticlesMove(), DropletBoundary(), and setGenerateDroplets().

lostVolume

double DropletBoundary::lostVolume = 0

Referenced by checkBoundaryAfterParticlesMove().

removeDropletsAtWalls_

bool DropletBoundary::removeDropletsAtWalls_ = true

private

Referenced by actionsBeforeTimeLoop(), checkBoundaryAfterParticlesMove(), DropletBoundary(), and setRemoveDropletsAtWalls().

---

The documentation for this class was generated from the following files:

• DropletBoundary.h
• DropletBoundary.cc