PLUTO  4.4-patch2
Functions
hll_speed.c File Reference

Compute the outermost wave speeds for HLL-based solvers. More...

#include "pluto.h"

Functions

void HLL_Speed (const State *stateL, const State *stateR, double *SL, double *SR, int beg, int end)
 

Detailed Description

HLL_Speed() computes an estimate to the leftmost and rightmost wave signal speeds bounding the Riemann fan based on the input states ::stateL->v, ::stateR->v. Depending on the estimate, several variants are possible.

Authors
A. Mignone (migno.nosp@m.ne@t.nosp@m.o.inf.nosp@m.n.it)
Date
June 25, 2019

Function Documentation

◆ HLL_Speed()

void HLL_Speed ( const State stateL,
const State stateR,
double *  SL,
double *  SR,
int  beg,
int  end 
)

Compute leftmost (SL) and rightmost (SR) speeds for the Riemann fan.

Parameters
[in]stateLpointer to a state structure for the left state
[in]stateRpointer to a state structure for the right state
[out]SLthe (estimated) leftmost speed of the Riemann fan
[out]SRthe (estimated) rightmost speed of the Riemann fan
[in]begstarting index of computation
[in]endfinal index of computation

Switches:

ROE_ESTIMATE (YES/NO), DAVIS_ESTIMATE (YES/NO). TVD_ESTIMATE (YES/NO) JAN_HLL (YES/NO)

These switches set how the wave speed estimates are going to be computed. Only one can be set to 'YES', and the rest of them must be set to 'NO'

ROE_ESTIMATE: b_m = (0, (u_R - c_R, u_L - c_L, u_{roe} - c_{roe})) b_m = (0, (u_R + c_R, u_L + c_L, u_{roe} + c_{roe}))

where u_{roe} and c_{roe} are computed using Roe averages.

DAVIS_ESTIMATE: b_m = (0, (u_R - c_R, u_L - c_L)) b_m = (0, (u_R + c_R, u_L + c_L))