Super Time Stepping driver for integration of diffusion terms. More...

#include "pluto.h"

Functions
static void	STS_ComputeSubSteps (double, double tau[], int)

void	STS (const Data d, Time_Step Dts, Grid *grid)

Detailed Description

Take one step in the solution of the diffusion equation $ dV/dt = R $ where R is a nonlinear right hand side involving second derivatives. The super step is taken to be equal to the current time step g_dt and the number of steps Nsts is given by solving Eq. (??) of Alexiades et al. with the explicit parabolic time step being computed from

$\frac{2}{N_d} \max\left[ \frac{\eta_x}{\Delta x^2} + \frac{\eta_y}{\Delta y^2} + \frac{\eta_z}{\Delta z^2} \right] \Delta t_{exp} = C_p < \frac{1}{N_d}$

where $C_p$ is the parabolic Courant number, $ N_d $ is the number of spatial dimensions and the maximum of the square bracket is computed during the call to ParabolicRHS.

This function is called in an operator-split way before/after advection has been carried out.

References

Alexiades, V., Amiez, A., & Gremaud E.-A. 1996, Com. Num. Meth. Eng., 12, 31

Authors: A. Mignone (migno.nosp@m.ne@p.nosp@m.h.uni.nosp@m.to.i.nosp@m.t)
T. Matsakos

Date: Oct 29, 2012

Function Documentation

void STS	(	const Data *	d,
		Time_Step *	Dts,
		Grid *	grid
	)

Solve diffusion equation using Super-Time-Stepping.

Parameters

[in,out]	d	pointer to Data structure
[in,out]	Dts	pointer to Time_Step structure
[in]	grid	pointer to an array of Grid structures

void STS_ComputeSubSteps	(	double	dtex,
		double	tau[],
		int	ssorder
	)

static

< $\pi$ .

Functions

Detailed Description

Function Documentation