/// <summary>
/// Calculate the tensors to implement the added damping model (Banks et.al. 2017)
/// </summary>
/// <param name="particle"></param>
/// <param name="levelSetTracker"></param>
/// <param name="fluidViscosity"></param>
/// <param name="fluidDensity"></param>
/// <param name="dt"></param>
internal override void CalculateDampingTensor(Particle particle, LevelSetTracker levelSetTracker, double fluidViscosity, double fluidDensity, double dt)
{
AddedDamping = new ParticleAddedDamping();
Aux = new FSI_Auxillary();
AddedDampingTensor = AddedDamping.IntegrationOverLevelSet(particle, levelSetTracker, fluidViscosity, fluidDensity, dt, GetPosition(0));
Aux.TestArithmeticException(AddedDampingTensor, "particle added damping tensor");
}
/// <summary>
/// Constructor for an arbitrary particle to be implemented in the Particle_Shape classes.
/// </summary>
/// <param name="motionInit">
/// Initializes the motion parameters of the particle (which model to use, whether it is a dry simulation etc.)
/// </param>
/// <param name="startPos">
/// The initial position.
/// </param>
/// <param name="startAngl">
/// The inital anlge.
/// </param>
/// <param name="activeStress">
/// The active stress excerted on the fluid by the particle. Zero for passive particles.
/// </param>
/// <param name="startTransVelocity">
/// The inital translational velocity.
/// </param>
/// <param name="startRotVelocity">
/// The inital rotational velocity.
/// </param>
public Particle(ParticleMotionInit motionInit, double[] startPos, double startAngl = 0.0, double activeStress = 0, double[] startTransVelocity = null, double startRotVelocity = 0)
{
SpatialDim = startPos.Length;
ActiveStress = activeStress;
m_MotionInit = motionInit;
Aux = new FSI_Auxillary();
m_MotionInit.CheckInput();
Motion = m_MotionInit.ParticleMotion;
Motion.InitializeParticlePositionAndAngle(startPos, startAngl);
Motion.InitializeParticleVelocity(startTransVelocity, startRotVelocity);
particleDensity = Motion.Density;
}
/// <summary>
/// Calculates the radial vector (SurfacePoint-ParticleReadOnlyPosition)
/// </summary>
/// <param name="SurfacePoint">
/// </param>
/// <param name="RadialVector">
/// </param>
/// <param name="RadialLength">
/// </param>
internal void CalculateRadialVector(Vector SurfacePoint, out Vector RadialVector, out double RadialLength)
{
Aux = new FSI_Auxillary();
RadialVector = new Vector(SurfacePoint[0] - Motion.GetPosition(0)[0], SurfacePoint[1] - Motion.GetPosition(0)[1]);
if (RadialVector.L2Norm() == 0)
{
throw new ArithmeticException("The radial vector has no length");
}
RadialLength = RadialVector.Abs();
RadialVector.ScaleV(1 / RadialLength);
Aux.TestArithmeticException(RadialVector, "particle radial vector");
Aux.TestArithmeticException(RadialLength, "particle radial length");
}
/// <summary>
/// Used during init of the particle. Sets the position and the angle.
/// </summary>
/// <param name="initialPosition">
/// The initial position.
/// </param>
/// <param name="initialAngle">
/// The initial angle.
/// </param>
internal void InitializeParticlePositionAndAngle(double[] initialPosition, double initialAngle, int historyLength = 0)
{
if (historyLength == 0)
{
historyLength = NumberOfHistoryEntries;
}
Aux = new FSI_Auxillary();
for (int i = 0; i < historyLength; i++)
{
Position[i] = new Vector(initialPosition);
Angle[i] = initialAngle * 2 * Math.PI / 360;
Aux.TestArithmeticException(Position[i], "initial particle position");
Aux.TestArithmeticException(Angle[i], "initial particle angle");
}
}
/// <summary>
/// Returns the support point of the particle in the direction specified by a vector.
/// </summary>
/// <param name="vector">
/// A vector.
/// </param>
override public Vector GetSupportPoint(Vector supportVector, int SubParticleID)
{
Aux = new FSI_Auxillary();
Aux.TestArithmeticException(supportVector, "vector in calc of support point");
if (supportVector.L2Norm() == 0)
{
throw new ArithmeticException("The given vector has no length");
}
Vector SupportPoint = new Vector(SpatialDim);
double angle = Motion.GetAngle(0);
Vector position = new Vector(Motion.GetPosition(0));
double[,] rotMatrix = new double[2, 2];
rotMatrix[0, 0] = m_Length * Math.Cos(angle);
rotMatrix[0, 1] = -m_Thickness *Math.Sin(angle);
rotMatrix[1, 0] = m_Length * Math.Sin(angle);
rotMatrix[1, 1] = m_Thickness * Math.Cos(angle);
double[,] transposeRotMatrix = rotMatrix.CloneAs();
transposeRotMatrix[0, 1] = rotMatrix[1, 0];
transposeRotMatrix[1, 0] = rotMatrix[0, 1];
double[] rotVector = new double[2];
for (int i = 0; i < 2; i++)
{
for (int j = 0; j < 2; j++)
{
rotVector[i] += transposeRotMatrix[i, j] * supportVector[j];
}
}
rotVector.ScaleV(1 / rotVector.L2Norm());
for (int i = 0; i < 2; i++)
{
for (int j = 0; j < 2; j++)
{
SupportPoint[i] += rotMatrix[i, j] * rotVector[j];
}
SupportPoint[i] += position[i];
}
return(SupportPoint);
}
