PLUTO  4.4-patch2
Functions
tvdlf.c File Reference

Lax-Friedrechs (Rusanov) Riemann solver for HD. More...

#include "pluto.h"

Functions

void LF_Solver (const Sweep *sweep, int beg, int end, double *cmax, Grid *grid)
 

Detailed Description

Solve the Riemann problem for the adiabatic and isothermal HD equations using the Lax-Friedrichs Rusanov Riemann solver with local maximum characteristic speed:

\[ \hat{F}_{i+\HALF} = \frac{F^L_{i+\HALF} + F^R_{i+\HALF}}{2} - c^{\rm max}_{i+\HALF}\frac{U^R_{i+\HALF} - U^L_{i-\HALF}}{2} \qquad{\rm where}\quad c^{\rm max} = \lambda_{\rm max}\left( \frac{V^R_{i+\HALF} + V^L_{i+\HALF}}{2}\right) \]

where $\lambda_{\rm \max}$ is a function of the arithmetic average between the left and the right states.

On input, this function takes left and right primitive state vectors stateL->v and stateR->v at zone edge i+1/2; On output, return flux and pressure vectors at the same interface i+1/2 (note that the i refers to i+1/2).

Also during this step, compute maximum wave propagation speed (cmax) for explicit time step computation.

Reference:

Authors
A. Mignone (migno.nosp@m.ne@t.nosp@m.o.inf.nosp@m.n.it)
Date
Feb 13, 2018

Function Documentation

◆ LF_Solver()

void LF_Solver ( const Sweep sweep,
int  beg,
int  end,
double *  cmax,
Grid grid 
)
Parameters
[in,out]sweeppointer to Sweep structure
[in]beginitial grid index
[out]endfinal grid index
[out]cmax1D array of maximum characteristic speeds
[in]gridpointer to array of Grid structures.