adam_flume_sinks_object

ADAM, FLUME sink particles: the [sinks] input and the replicated sink list (issue #94, M12).

A sink is a point mass with a position, a velocity and an acceleration. The list is replicated: every rank holds every sink and updates it identically from MPI-reduced sums (D-M12-1), so no sink has an owner and none migrates. Sinks act through self-gravity only (D-M12-2): their mass is CIC-deposited into the density the Poisson solver sees and they feel the mesh gravity at their position (the deposit and the gather live in the common object, which owns the grid). The keys, lists of one value per initial sink (their number is that of mass; none: no initial sink):

key	value
x, y, z	positions, inside the domain
u, v, w	velocities (optional, default 0)
mass	masses, > 0
creation	optional, default .false.: sinks form where the gas meets the Federrath et al. (2010) checks
accretion	optional, default .true.: the sinks accrete the gas above the threshold within their radius
merging	optional, default .true.: two bound, converging sinks within an accretion radius merge
accretion_radius_cells	optional, default 2.5: the accretion radius in cells of the sink's level, in [1, ngc]

With runtime regridding ([amr] frequency > 0) the sinks live on the finest level allowed: they form there only, the accretion radius is in its cells and their neighbourhood is kept there at every regrid (D-M12-5).

The threshold density is that of a Jeans length of two accretion radii, rho_thr = pi c_s^2 / (4 G r_acc^2), with the cell's own c_s^2 = gamma p / rho (the Jeans length of the M9 marker; issue #94, D-M12-3, D-M12-4).

With the section, [gravity] self_gravity is required and the model must be hydrodynamic (fatal otherwise, issue #94: MHD sinks are a follow-up). The [reference] layer converts the positions (length), the velocities and the masses (rho0 L0^3). Restart: <restart_basename>.sinks, the list in 17 significant digits (read back, the same doubles). History: <output_basename>-sinks_history.dat, one row per sink per save (it time id m x y z u v w).

Source: src/app/flume/common/adam_flume_sinks_object.F90

Dependencies

Contents

• flume_sinks_object
• append
• remove
• load_from_file
• load_restart
• open_history
• save_history
• save_restart
• totals
• description

Variables

Name	Type	Attributes	Description
INI_SECTION_NAME	character(len=5)	parameter	INI section name.

Derived Types

flume_sinks_object

FLUME sink particles, code units.

Components

Name	Type	Attributes	Description
is_active	logical		True with a [sinks] section.
n	integer(kind=I4P)		Sinks number.
m	real(kind=R8P)	allocatable	Masses [n].
x	real(kind=R8P)	allocatable	Positions [3,n].
v	real(kind=R8P)	allocatable	Velocities [3,n].
a	real(kind=R8P)	allocatable	Accelerations from the mesh gravity [3,n].
dt_limit	real(kind=R8P)		Time step limit of the current list (refreshed after each update).
is_new	logical	allocatable	True for a sink formed this step (its first accretion is unchecked).
creation	logical		Sinks form from the gas.
accretion	logical		Sinks accrete.
merging	logical		Sinks merge.
r_acc_cells	real(kind=R8P)		Accretion radius in cells.
formed	integer(kind=I4P)		Sinks formed since the start of the run.
merged	integer(kind=I4P)		Mergers since the start of the run.
history_unit	integer(kind=I4P)		Sinks history unit (rank 0).

Type-Bound Procedures

Name	Attributes	Description
append	pass(self)	Append a sink.
description	pass(self)	Return pretty-printed object description.
remove	pass(self)	Remove a sink.
load_from_file	pass(self)	Load [sinks].
load_restart	pass(self)	Load the list from .sinks.
open_history	pass(self)	Open the sinks history (rank 0).
save_history	pass(self)	Write one history row per sink (rank 0).
save_restart	pass(self)	Save the list to .sinks (rank 0).
totals	pass(self)	Return the total mass, momentum and kinetic energy.

Subroutines

append

Append a sink (every rank, identically: the list is replicated); it is new until its first accretion. The arrays grow by explicit allocation (no reallocation on assignment: under nvfortran it intermittently failed to grow an array in the sink code, issue #94).

subroutine append(self, m, x, v)

Arguments

Name	Type	Intent	Attributes	Description
self	class(flume_sinks_object)	inout		Sinks.
m	real(kind=R8P)	in		Mass.
x	real(kind=R8P)	in		Position.
v	real(kind=R8P)	in		Velocity.

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remove

Remove sink s (every rank, identically), by explicit allocation (see append).

subroutine remove(self, s)

Arguments

Name	Type	Intent	Attributes	Description
self	class(flume_sinks_object)	inout		Sinks.
s	integer(kind=I4P)	in		Sink to remove.

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load_from_file

Load [sinks] and check it.

subroutine load_from_file(self, file_parameters, model, self_gravity, domain_emin, domain_emax, ngc)

Arguments

Name	Type	Intent	Attributes	Description
self	class(flume_sinks_object)	inout		Sinks.
file_parameters	type(file_ini)	in		Simulation parameters ini file handler.
model	integer(kind=I4P)	in		Physical model id.
self_gravity	logical	in		[gravity] self_gravity.
domain_emin	real(kind=R8P)	in		Domain minimum abscissa.
domain_emax	real(kind=R8P)	in		Domain maximum abscissa.
ngc	integer(kind=I4P)	in		Ghost cells number (bounds the accretion radius).

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load_restart

Load the list from <basename>.sinks (every rank reads it: the list is replicated).

subroutine load_restart(self, basename)

Arguments

Name	Type	Intent	Attributes	Description
self	class(flume_sinks_object)	inout		Sinks.
basename	character(len=*)	in		Restart files basename.

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open_history

Open the sinks history (rank 0) and write its header (append, without header, on restart).

subroutine open_history(self, output_basename, is_restart)

Arguments

Name	Type	Intent	Attributes	Description
self	class(flume_sinks_object)	inout		Sinks.
output_basename	character(len=*)	in		Output files basename.
is_restart	logical	in		Restarted run flag.

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save_history

Write one history row per sink (rank 0), the values times the output factors.

subroutine save_history(self, it, time, length, velocity, mass)

Arguments

Name	Type	Intent	Attributes	Description
self	class(flume_sinks_object)	in		Sinks.
it	integer(kind=I4P)	in		Time iteration.
time	real(kind=R8P)	in		Time (output units).
length	real(kind=R8P)	in		Output factor of the lengths.
velocity	real(kind=R8P)	in		Output factor of the velocities.
mass	real(kind=R8P)	in		Output factor of the masses.

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save_restart

Save the list to <basename>.sinks (rank 0), 17 significant digits: read back, the same doubles.

subroutine save_restart(self, basename)

Arguments

Name	Type	Intent	Attributes	Description
self	class(flume_sinks_object)	in		Sinks.
basename	character(len=*)	in		Restart files basename.

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totals

Return the total mass, momentum and kinetic energy of the sinks.

Attributes: pure

subroutine totals(self, mass, momentum, kinetic)

Arguments

Name	Type	Intent	Attributes	Description
self	class(flume_sinks_object)	in		Sinks.
mass	real(kind=R8P)	out		Total mass.
momentum	real(kind=R8P)	out		Total momentum.
kinetic	real(kind=R8P)	out		Total kinetic energy.

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Functions

description

Return a pretty-formatted object description.

Returns: character(len=:)

function description(self) result(desc)

Arguments

Name	Type	Intent	Attributes	Description
self	class(flume_sinks_object)	in		Sinks.

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