toolbox::particles::potentials Namespace Reference

Functions
tarch::la::Vector< Dimensions, double >	springPotential (const tarch::la::Vector< Dimensions, double > &p1, const tarch::la::Vector< Dimensions, double > &p2, double h)
	Assumes that there is no force in-between two particles p1 and p2 if they are h away from each other.

Function Documentation

springPotential()

tarch::la::Vector< Dimensions, double > toolbox::particles::potentials::springPotential	(	const tarch::la::Vector< Dimensions, double > &	p1,
		const tarch::la::Vector< Dimensions, double > &	p2,
		double	h
	)

Assumes that there is no force in-between two particles p1 and p2 if they are h away from each other.

If they are closer than that, there's repulsion. Otherwise, we have attraction. The force quantity is realised through an inverted Lennard-Jones potential for the attraction, i.e. if two particles are slightly too far away from each other, they attract each other. When they are further away, this attraction also fades away. This way, we can work with local support (search radii) and we can handle huge domains. In return, two particles repulse each other if they are too close. However, I do truncate this repulsion, as I want to ensure that these spring forces do not explode. So I kind of truncate it in the interval [-1,+1].

Parameters

p1	Position of the particle of interest, i.e. the one that is to be evaluated
p2	Position of comparison particle
h	This is the spacing particles should have

The potential's force should usually scale with the time step size, but it is the job of the user of this routine to ensure proper scaling.

Returns

Vector from p1 to p2 representing a force.