Strategy functions for calculating the position of one or more particles. More...

#include "objects/CellContainer.h"
#include "objects/ParticleContainer.h"

Functions
void	calculateX (ParticleContainer &particles, double delta_t, double g_grav, CellContainer *lc=nullptr, bool membrane=false)
	Calculates the position \( x \) for all Particle objects in a given ParticleContainer.

void	calculateX_LC (ParticleContainer &particles, double delta_t, double g_grav, CellContainer *lc, bool membrane=false)
	Calculates the position \( x \) for all Particle objects in a given ParticleContainer when using the linked cells method.

Detailed Description

Strategy functions for calculating the position of one or more particles.

Date: 2024-11-11

Copyright: Copyright (c) 2024

Function Documentation

◆ calculateX()

void calculateX	(	ParticleContainer &	particles,
		double	delta_t,
		double	g_grav,
		CellContainer *	lc = `nullptr`,
		bool	membrane = `false`
	)

Calculates the position \( x \) for all Particle objects in a given ParticleContainer.

The position \( x_i \) of a given particle \( i \) at the next unit of time \( t_{n+1} \) is calculated using the formula

\[ x_i(t_{n+1}) = x_i(t_n) + \Delta t \cdot v_i(t_n) + (\Delta t)^2 \frac{F_i(t_n)}{2m_i}. \]

As an optimization, in order to prevent looping through all particles once more to reset the existing force and potentially apply gravity in the upcoming force calculation step of the time integration, this is done at the end of this function instead. If the gravity is set to 0, the force applied to all active particles will be zeroed instead.

Parameters

particles	The ParticleContainer containing the Particle objects to iterate over.
delta_t	The timestep \( \Delta t \).
g_grav	The gravitational force \( g_{grav} \).
lc	Unused. Present to allow calling function without last argument.
membrane	Unused. Present to allow calling function without last argument.

◆ calculateX_LC()

void calculateX_LC	(	ParticleContainer &	particles,
		double	delta_t,
		double	g_grav,
		CellContainer *	lc,
		bool	membrane = `false`
	)

Calculates the position \( x \) for all Particle objects in a given ParticleContainer when using the linked cells method.

The position update occurs analogously to the default, non-linked-cell function.

After each update, the particle may need to be moved to a different cell. The algorithm checks this and updates the cell correspondence accordingly. If the particle enters a halo cell, the appropriate boundary condition will be applied.

If a particle enters a corner halo cell where one side has a different boundary condition to the other, the condition is chosen based on which boundary the particle will hit first. See the report and presentation for more details.