- 4.4.5.1 rhd_hyd_gravcorr_p01
- 4.4.5.2 rhd_hyd_entropyfix_p01
- 4.4.5.3 rhd_hyd_upwind_p01
- 4.4.5.4 rhd_roe1d_flux_l01
- 4.4.5.5 rhd_bound_t01
- 4.4.5.6 rhd_roe1d_flux_t01
- 4.4.5.7 rhd_roe1d_step_t01

4.4.5.1 rhd_hyd_gravcorr_p01

`rhd_hyd_module.F90`

.
Category: selection of approximation.

This parameter controls the way the Roe solver handles the source terms due to gravity. A different choice results in different simulation results and not just in slightly faster (or slower) code. The problem is that the original Roe solver interpretes the pressure gradient in a hydrostatic stratification a fluctuation due to shock waves. In case of strong stratification this can lead to weird effects. With activated correction the Roe solver treats only the deviations from a hydrostatic stratification as due to waves (or shocks). Several correction formulas have been tried. The latest is the recommended default. Values:

`0`

: No pressure correction terms in Roe solver.`1`

: Simple correction with rhomean, no new average pressure.`2`

: Simple correction with rhomean, new average pressure.`3`

: Correction with local rho, limited, new average pressure.`4`

: Correction with local rho, new (different formula) average pressure.`5`

: (default) Correction with local rho, new limit, new average pressure.`6`

: Modification of`5`

with different geometry factors in case of non-equidistant grid.

4.4.5.2 rhd_hyd_entropyfix_p01

`rhd_hyd_module.F90`

.
Category: performance enhancement.

The entropy fix can be done in one of two ways to get optimum performance (with essentially the same results). Values:

`0`

: (default) ``if...then...else'' construction`1`

: use a mask and the signum function

4.4.5.3 rhd_hyd_upwind_p01

`rhd_hyd_module.F90`

.
Category: performance enhancement.

The determination of the upwind direction can be done in one of two ways to get optimum performance (with essentially the same results). Values:

`0`

: (default) ``if...then...else'' construction`1`

: use a mask and the signum function

4.4.5.4 rhd_roe1d_flux_l01

`rhd_hyd_module.F90`

.
Category: performance enhancement.

This switch allows to choose between various ways of computing the upwind-centered Roe states. Values:

`0`

: Use upwind-index arrays in all Roe-state computations. Do it in one step (old default).`1`

: Use if-then-else-constructs in all Roe-state computations. Do it in one step (default, recommended).`2`

: Use upwind-index arrays in all Roe-state computations. Do it in two steps.`3`

: Use if-then-else-constructs in all Roe-state computations. Do it in two steps.

4.4.5.5 rhd_bound_t01

`rhd_hyd_module.F90`

.
Category: additional output.

Produce timing information for ``inner boundary'' routine (central potential) or lower and upper boundary routines (constant gravitation). It can be used together with OpenMP. Values:

`undefined`

: (default) no timing information.`defined`

: call subroutines to measure elapsed time.

4.4.5.6 rhd_roe1d_flux_t01

`rhd_hyd_module.F90`

.
Category: additional output.

Produce timing information for the routine which computes the Roe fluxes. It should not be used in conjunction with OpenMP. Values:

`undefined`

: (default) no timing information`defined`

: call subroutines to measure elapsed time

4.4.5.7 rhd_roe1d_step_t01

`rhd_hyd_module.F90`

.
Category: additional output.

Produce timing information for the routine which performs the Roe step. It should not be used in conjunction with OpenMP. Values:

`undefined`

: (default) no timing information`defined`

: call subroutines to measure elapsed time