ID_onverter_LGRMHD: A Module for Converting HydroBase Initial Data into Variables IllinoisGRMHD Can Read

ID_Converter_ILGRMHD: A Module for Converting HydroBase Initial Data into Variables IllinoisGRMHD Can Read

Original author: Zachariah B. Etienne.

Date: 2015-10-12 12:00:00 -0600 (Mon, 12 Oct 2015)

Abstract

IllinoisGRMHD and HydroBase variables are incompatible; The former uses 3-velocity defined as $v^{i} = u^{i} ∕ u^{0}$ , and the latter uses the Valencia formalism definition of $v^{i}$ .

Define the Valencia formalism’s definition of $v^{i}$ to be ” $W^{i}$ ”, and IllinoisGRMHD’s definition ” $v^{i}$ ” Then

W^{i} = (v^{i} + β^{i}) ∕ (α),

(1)

which comes from Eq 11 in the IllinoisGRMHD code announcement paper:
http://arxiv.org/pdf/1501.07276.pdf.

Similarly,

v_{i} = (α) W^{i} - β^{i}

(2)

In addition, IllinoisGRMHD needs the A-fields to be defined on staggered grids, and HydroBase does not yet support this option. The staggerings are defined in Table 1 of the IllinoisGRMHD code announcement paper:
http://arxiv.org/pdf/1501.07276.pdf (page 15).

The long-term goal should be to adjust HydroBase and IllinoisGRMHD so that this thorn is no longer necessary.

1 Parameters


gamma_initial	Scope: private	REAL

Description: Single Gamma-law EOS: Gamma

Range		Default: 1.3
0:*	Positive or zero


k_initial	Scope: private	REAL

Description: Single Gamma-law EOS: K

Range		Default: 1.0
0:*	Positive or zero


pure_hydro_run	Scope: private	BOOLEAN

Description: Set the vector potential and corresponding EM gauge quantity to zero

		Default: no


random_pert	Scope: private	REAL

Description: Random perturbation atop data

Range		Default: (none)
:	Anything goes.


random_seed	Scope: private	INT

Description: Random seed for random, generally roundoff-level perturbation on initial data. Seeds srand(), and rand() is used for the RNG.

Range		Default: (none)
0:99999999	Anything unsigned goes.


gamma_speed_limit	Scope: shared from ILLINOISGRMHD	REAL


gamma_th	Scope: shared from ILLINOISGRMHD	REAL


k_poly	Scope: shared from ILLINOISGRMHD	REAL


neos	Scope: shared from ILLINOISGRMHD	INT


psi6threshold	Scope: shared from ILLINOISGRMHD	REAL


rho_b_atm	Scope: shared from ILLINOISGRMHD	REAL


rho_b_max	Scope: shared from ILLINOISGRMHD	REAL


sym_bz	Scope: shared from ILLINOISGRMHD	REAL


tau_atm	Scope: shared from ILLINOISGRMHD	REAL


update_tmunu	Scope: shared from ILLINOISGRMHD	BOOLEAN

2 Interfaces

General

Implements:

id_converter_ilgrmhd

Inherits:

admbase

boundary

spacemask

tmunubase

hydrobase

grid

illinoisgrmhd

Uses header:

IllinoisGRMHD_headers.h

Symmetry.h

3 Schedule

This section lists all the variables which are assigned storage by thorn WVUThorns/ID_converter_ILGRMHD. Storage can either last for the duration of the run (Always means that if this thorn is activated storage will be assigned, Conditional means that if this thorn is activated storage will be assigned for the duration of the run if some condition is met), or can be turned on for the duration of a schedule function.

Storage

Always:
HydroBase::Avec[1] HydroBase::Aphi[1]

Scheduled Functions

CCTK_INITIAL

illinoisgrmhd_id_converter

translate et-generated, hydrobase-compatible initial data and convert into variables used by illinoisgrmhd

	After:	hydrobase_initial
	Before:	convert_to_hydrobase
	Type:	group

IllinoisGRMHD_ID_Converter

set_illinoisgrmhd_metric_grmhd_variables_based_on_hydrobase_and_admbase_variables

convert hydrobase initial data (id) to id that illinoisgrmhd can read.

	Before:	tov_initial_data
	Language:	c
	Options:	local
	Sync:	illinoisgrmhd::grmhd_primitives_bi
		illinoisgrmhd::grmhd_primitives_bi_stagger
		illinoisgrmhd::grmhd_primitives_allbutbi
		illinoisgrmhd::em_ax
		illinoisgrmhd::em_ay
		illinoisgrmhd::em_az
		illinoisgrmhd::em_psi6phi
		illinoisgrmhd::grmhd_conservatives
		illinoisgrmhd::bssn_quantities
		admbase::metric
		admbase::lapse
		admbase::shift
		admbase::curv
	Type:	function

IllinoisGRMHD_ID_Converter

illinoisgrmhd_initsymbound

schedule symmetries – actually just a placeholder function to ensure prolongation / processor syncs are done before the primitives solver.

	After:	second_initialdata
	Language:	c
	Sync:	illinoisgrmhd::grmhd_conservatives
		illinoisgrmhd::em_ax
		illinoisgrmhd::em_ay
		illinoisgrmhd::em_az
		illinoisgrmhd::em_psi6phi
	Type:	function

IllinoisGRMHD_ID_Converter

illinoisgrmhd_compute_b_and_bstagger_from_a

compute b and b_stagger from a

	After:	third_initialdata
	Language:	c
	Sync:	illinoisgrmhd::grmhd_primitives_bi
		illinoisgrmhd::grmhd_primitives_bi_stagger
	Type:	function

IllinoisGRMHD_ID_Converter

illinoisgrmhd_conserv_to_prims

compute primitive variables from conservatives. this is non-trivial, requiring a newton-raphson root-finder.

	After:	fourth_initialdata
	Language:	c
	Type:	function

Aliased Functions

Alias Name:	Function Name:
IllinoisGRMHD_InitSymBound	third_initialdata
IllinoisGRMHD_compute_B_and_Bstagger_from_A	fourth_initialdata
IllinoisGRMHD_conserv_to_prims	fifth_initialdata
set_IllinoisGRMHD_metric_GRMHD_variables_based_on_HydroBase_and_ADMBase_variables	first_initialdata