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; viscosity_law = sutherland is Sutherland's law, mu (T / T_ref)^(3/2) (T_ref + S) / (T + S) with S = sutherland_temperature (110.4 K for air), a temperature in the units of reference_temperature (both converted by the [reference] layer); with [physics] temperature_unit_kelvin it may be omitted, and is then 110.4 K (Sutherland's constant of air) in code units. With prandtl the conductivity follows either law, 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.
VISCOSITY_LAW_SUTHERLAND	character(len=10)	parameter	[physics].(viscosity_law): Sutherland's law.
SUTHERLAND_AIR_KELVIN	real(kind=R8P)	parameter	Sutherland's constant of air [K].

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, power-law or sutherland.
viscosity_exponent	real(kind=R8P)		Power-law exponent omega.
reference_temperature	real(kind=R8P)		Reference temperature of the power or Sutherland law.
sutherland_temperature	real(kind=R8P)		Sutherland's constant S.
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 (temperature_law of adam_flume_dissipation_library), mu = mu0 L(T, omega_mu), k = k0 L(T, omega_k), L = (T / tref)^omega, times (tref + suth) / (T + suth) when suth > 0: the constant law is tref = 1 with zero exponents, Sutherland's omega = 3/2 with suth = S; under either law the conductivity follows the viscosity only when it comes from the Prandtl number.

Attributes: pure

subroutine laws(self, tref, suth, omega_mu, omega_k)

Arguments

Name	Type	Intent	Attributes	Description
self	class(flume_dissipation_object)	in		Dissipation.
tref	real(kind=R8P)	out		Reference temperature.
suth	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, kelvin)

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.
kelvin	real(kind=R8P)	in		Kelvin per code temperature unit, 0 if not given.

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.

Call graph