Velocity verlet particle dynamics with limitation of position and velocity by checking domain bounds in cartesion direcion and simple adhesive force threshold allowing particles only to move when both a normal and tangential force threshold have been surpassed. More...

#include <particleDynamicsBase.h>

Inheritance diagram for olb::particles::dynamics::VerletParticleDynamicsCubicBoundsAdhesion< T, PARTICLETYPE >:

Collaboration diagram for olb::particles::dynamics::VerletParticleDynamicsCubicBoundsAdhesion< T, PARTICLETYPE >:

Public Member Functions
	VerletParticleDynamicsCubicBoundsAdhesion (PhysR< T, PARTICLETYPE::d > &domainMin, PhysR< T, PARTICLETYPE::d > &domainMax)
	Constructor.

void	process (Particle< T, PARTICLETYPE > &particle, T timeStepSize) override
	Procesisng step.

Public Member Functions inherited from olb::particles::dynamics::ParticleDynamics< T, PARTICLETYPE >
virtual	~ParticleDynamics ()
	Destructor: virtual to enable inheritance.

std::string &	getName ()
	read and write access to name

std::string const &	getName () const
	read only access to name

Detailed Description

template<typename T, typename PARTICLETYPE>
class olb::particles::dynamics::VerletParticleDynamicsCubicBoundsAdhesion< T, PARTICLETYPE >

Velocity verlet particle dynamics with limitation of position and velocity by checking domain bounds in cartesion direcion and simple adhesive force threshold allowing particles only to move when both a normal and tangential force threshold have been surpassed.

Definition at line 423 of file particleDynamicsBase.h.

Constructor & Destructor Documentation

◆ VerletParticleDynamicsCubicBoundsAdhesion()

template<typename T , typename PARTICLETYPE >

olb::particles::dynamics::VerletParticleDynamicsCubicBoundsAdhesion< T, PARTICLETYPE >::VerletParticleDynamicsCubicBoundsAdhesion	(	PhysR< T, PARTICLETYPE::d > &	domainMin,
		PhysR< T, PARTICLETYPE::d > &	domainMax )

Constructor.

Definition at line 437 of file particleDynamicsBase.hh.

  : _domainMin(domainMin), _domainMax(domainMax)
{
  this->getName() = "VerletParticleDynamicsCubicBoundsAdhesion";
}

References olb::particles::dynamics::ParticleDynamics< T, PARTICLETYPE >::getName().

Here is the call graph for this function:

Member Function Documentation

◆ process()

template<typename T , typename PARTICLETYPE >

void olb::particles::dynamics::VerletParticleDynamicsCubicBoundsAdhesion< T, PARTICLETYPE >::process	(	Particle< T, PARTICLETYPE > &	particle,
		T	timeStepSize )

overridevirtual

Procesisng step.

In order to move, both normal and at least one of the tangential adhesion force components have to be surpassed, thus adhesionSuperior = adhesionSuperior || bothTangentalSuperior.
Carefull, when debugging: Dont't use << bool, but rather explicit if (bool){ << true } outputs.

Implements olb::particles::dynamics::ParticleDynamics< T, PARTICLETYPE >.

Definition at line 457 of file particleDynamicsBase.hh.

{
  using namespace particles::access;
  //Calculate acceleration
  auto acceleration = getAcceleration( particle );
  //Note position before calculating movement (and store in dynStatePre)
  DynState<T,PARTICLETYPE> dynStatePre( getPosition(particle) );
 
  //Check for angular components
  if constexpr ( providesAngle<PARTICLETYPE>() ) {
    //Calculate angular acceleration
    auto angularAcceleration = getAngAcceleration( particle );
    //Note angle before calculating rotation (and store in dynStatePre)
    dynStatePre.angle = getAngle( particle );
    //Verlet algorithm
    particles::dynamics::velocityVerletIntegration(
      particle, timeStepSize, acceleration, angularAcceleration );
  } else {
    //Verlet algorithm
    particles::dynamics::velocityVerletIntegration(
      particle, timeStepSize, acceleration);
  }
 
  //Retrieve force and adhesion threshold
  auto force = getForce( particle );
  auto adhesionThreshold = getAdhesion( particle );
 
  //Check domain contact and potentially reset to positionPre and velocity zero
  bool adhesionSuperior = false;
  doAtCubicBoundPenetration( particle, _domainMin, _domainMax,
  [&](unsigned iDim, Vector<T,PARTICLETYPE::d>& normal, T distToBound ) {
    //Reset (only!) penetration direction
    resetDirection( particle, dynStatePre.position, iDim );
    //Check adhesion in normal direction
    //-only consider contributions pointing from the surface (normalForce > 0)
    // to ensure, that pressing on particles does not release them
    T normalForce = force[iDim]*normal[iDim];
    if (normalForce > 0 && normalForce < adhesionThreshold[0] ){
      adhesionSuperior = true;
    }
    //Check adhesion in all tangential directions
    // - info: checks in both directions in both positive and negative direction
    bool bothTangentalSuperior = true;
    for (int iDimT=1; iDimT<PARTICLETYPE::d; ++iDimT) {
      int jDim = (iDim+iDimT)%PARTICLETYPE::d;
      if (std::abs(force[jDim]) >= adhesionThreshold[1]){  //Tangential direction (absolute)
        bothTangentalSuperior = false;
      }
    }
    //Combine normal and tangential evaluation
    adhesionSuperior = adhesionSuperior || bothTangentalSuperior;
  });
 
  if constexpr ( providesAngle<PARTICLETYPE>() ) {
    //Check whether adhesion is superior
    if (adhesionSuperior){
      resetMovement( particle, dynStatePre.position, dynStatePre.angle );
    }
    //Update rotation matrix
    updateRotationMatrix( particle );
  } else {
    //Check whether adhesion is superior
    if (adhesionSuperior){ resetMovement( particle, dynStatePre.position); }
  }
 
}

References olb::particles::dynamics::doAtCubicBoundPenetration(), olb::particles::dynamics::resetDirection(), olb::particles::dynamics::resetMovement(), olb::particles::dynamics::updateRotationMatrix(), and olb::particles::dynamics::velocityVerletIntegration().