adam_flume_dissipation_object

ADAM, FLUME dissipative coefficients: viscosity, heat conduction, Ohmic resistivity (issue #65, M4).

The coefficients are read from [physics], each either as a coefficient or as the dimensionless number it stands for (issue #49, N4, section 4.5); giving two keys of a term is fatal, giving none leaves the term off (ideal):

term	coefficient (code units)	number	coefficient from the number
viscosity	viscosity (dynamic, mu)	reynolds	mu = 1 / Re
heat conduction	conductivity (k)	prandtl	k = mu cp / Pr
Ohmic resistivity (MHD)	resistivity (magnetic diffusivity eta)	magnetic_reynolds, lundquist	1 / Rm, 1 / S

In code units the references are 1, so a number is the reciprocal coefficient. The [reference] layer converts the dimensional coefficients (mu: length x velocity x density; k the same divided by the gas constant; eta: length x velocity) and leaves the numbers as they are; lundquist needs its Alfvenic preset (the velocity unit is then the Alfven speed and S is Rm). The heat flux is -k grad T with T = p / (rho R).

viscosity_law = power-law makes the viscosity depend on the temperature, mu (T / reference_temperature) ** viscosity_exponent; with prandtl the conductivity follows it, k = mu(T) cp / Pr.

The viscous and heat-conduction kernels landed in issue #65 P2 (Euler), the MHD ones land in P3: until then a non-zero coefficient with an MHD model is refused at initialisation by the common object, so no coefficient is ever ignored silently.

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

Dependencies

Contents

• flume_dissipation_object
• laws
• load_from_file
• description

Variables

Name	Type	Attributes	Description
INI_SECTION_NAME	character(len=7)	parameter	INI section of the coefficients.
VISCOSITY_LAW_CONSTANT	character(len=8)	parameter	[physics].(viscosity_law): constant mu.
VISCOSITY_LAW_POWER	character(len=9)	parameter	[physics].(viscosity_law): mu (T / T_ref)^omega.

Derived Types

flume_dissipation_object

FLUME dissipative coefficients, code units.

Components

Name	Type	Attributes	Description
mu	real(kind=R8P)		Dynamic viscosity (at the reference temperature).
k	real(kind=R8P)		Thermal conductivity (with Prandtl: at mu).
eta	real(kind=R8P)		Magnetic diffusivity (Ohmic resistivity).
prandtl	real(kind=R8P)		Prandtl number, 0 when k is given directly.
viscosity_law	character(len=:)	allocatable	Viscosity law: constant or power-law.
viscosity_exponent	real(kind=R8P)		Power-law exponent omega.
reference_temperature	real(kind=R8P)		Power-law reference temperature.
has_viscosity	logical		mu > 0.
has_conduction	logical		k > 0.
has_resistivity	logical		eta > 0.
is_active	logical		Any term on.

Type-Bound Procedures

Name	Attributes	Description
description	pass(self)	Return pretty-printed object description.
laws	pass(self)	Return the temperature laws of the kernels.
load_from_file	pass(self)	Load the coefficients from file.

Subroutines

laws

Return the temperature laws as the kernels take them, mu = mu0 (T / tref)^omega_mu, k = k0 (T / tref)^omega_k: the constant law is tref = 1 with zero exponents; under the power law the conductivity follows the viscosity only when it comes from the Prandtl number.

Attributes: pure

subroutine laws(self, tref, omega_mu, omega_k)

Arguments

Name	Type	Intent	Attributes	Description
self	class(flume_dissipation_object)	in		Dissipation.
tref	real(kind=R8P)	out		Reference temperature.
omega_mu	real(kind=R8P)	out		Exponents.
omega_k	real(kind=R8P)	out		Exponents.

Call graph

load_from_file

Load the coefficients: a coefficient or its number per term (two keys of a term are fatal, none is the ideal 0).

subroutine load_from_file(self, file_parameters, model, cp)

Arguments

Name	Type	Intent	Attributes	Description
self	class(flume_dissipation_object)	inout		Dissipation.
file_parameters	type(file_ini)	in		Simulation parameters ini file handler.
model	integer(kind=I4P)	in		Physical model id.
cp	real(kind=R8P)	in		Specific heat at constant pressure, code units.

Call graph

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_dissipation_object)	in		Dissipation.

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