Code_Aster
®
Version
7.4
Titrate:
Operator
THER_NON_LINE_MO
Date:
20/01/05
Author (S):
C. DURAND
Key
:
U4.54.03-D
Page
:
1/6
Instruction manual
U4.5- booklet: Methods of resolution
HT-66/05/004/A
Organization (S):
EDF-R & D/AMA
Instruction manual
U4.5- booklet: Methods of resolution
Document: U4.54.03
Operator
THER_NON_LINE_MO
1 Goal
To calculate the nonlinear stationary thermal response with mobile loading.
This operator allows to solve the equation of stationary heat in a mobile reference frame related to
a loading and moving in a given direction and at a speed [R5.02.04].
Nonthe linearities of the problem come as well from the characteristics of material which depend
temperature, that boundary conditions of the radiation type.
The problems of this type can be dealt with with models using of the finite elements of
structure plans, axisymmetric and three-dimensional.
The concept produced by this operator is of type
evol_ther
as for an analysis by
THER_LINEAIRE
[U4.54.01] or
THER_NON_LINE
[U4.54.02], but it contains one number
of command since a stationary calculation is carried out.
Code_Aster
®
Version
7.4
Titrate:
Operator
THER_NON_LINE_MO
Date:
20/01/05
Author (S):
C. DURAND
Key
:
U4.54.03-D
Page
:
2/6
Instruction manual
U4.5- booklet: Methods of resolution
HT-66/05/004/A
2 Syntax
temper [evol_ther] = THER_NON_LINE_MO
(
MODEL
=
Mo,
[model]
CHAM_MATER =
chmat,
[cham_mater]
EXCIT
=_
F
(
CHARGE
=
tank,
[char_ther]
),
TEMP_INIT =_F (
EVOL_THER
=
temp,
[evol_ther]
NUME_INIT
=/nuini_evol, [I]
/
0,
[DEFECT]
),
CONVERGENCE =_F (
CRIT_TEMP_RELA =/1.E-3,
[DEFECT]
/
testr,
[R]
CRIT_ENTH_RELA =/1.E-2,
[DEFECT]
/
testl,
[R]
ITER_GLOB_MAXI =/10,
[DEFECT]
/
iterl,
[R]
),
SOLVEUR
=_F (see document [U4.50.01])
),
TITRATE
=
titrate,
[l_Kn]
);
Code_Aster
®
Version
7.4
Titrate:
Operator
THER_NON_LINE_MO
Date:
20/01/05
Author (S):
C. DURAND
Key
:
U4.54.03-D
Page
:
3/6
Instruction manual
U4.5- booklet: Methods of resolution
HT-66/05/004/A
3 Operands
3.1 Operand
MODEL
MODEL = Mo
Name of the model whose elements are the subject of thermal calculation.
3.2 Operand
CHAM_MATER
CHAM_MATER = chmat
Name of the affected material field on the model.
3.3 Word
key
EXCIT
EXCIT
=
Key word factor allowing to define several loadings. For each occurrence of the key word
factor, one defines a time-constant load.
3.3.1 Operand
CHARGE
CHARGE = tank
Concept of the type
charge
product by
AFFE_CHAR_THER
or by
AFFE_CHAR_THER_F
[U4.44.02].
Important remarks:
For each occurrence of the key word factor
EXCIT
various concepts
tank
used
must be built on the same model
Mo
.
In addition, the operator
AFFE_CHAR_THER
or
AFFE_CHAR_THER_F
must obligatorily
to inform under the key word factor
CONVECTION
a concept of the type
cham_no_DEPL_R
defining the rate of travel of the field and product by
AFFE_CHAM_NO
.
It is necessary to take care to define boundary conditions coherent with the run of the part
(or of the loading, according to the selected reference frame) and the assumption of stationnarity:
If the solid is animated of a uniform translatory movement at constant speed, it is
equivalent to consider the field of temperature calculated:
· like a photograph at a given moment,
· or like a temporal succession of the card of temperature in a section
of fixed, orthogonal X-coordinate with the direction of run.
v = scrolling speed
Mobile loading
T = 0
T = infinite
time
Adiabatic C.L
C.L temperature
imposed
Thus, downstream under space (early in time), the boundary condition on the edge of
coin must impose the temperature of the coin before does not arrive the mobile loading.
Upstream in space (or late in time), a heat flux no one (adiabaticity)
the assumption of stationnarity guarantees.
Code_Aster
®
Version
7.4
Titrate:
Operator
THER_NON_LINE_MO
Date:
20/01/05
Author (S):
C. DURAND
Key
:
U4.54.03-D
Page
:
4/6
Instruction manual
U4.5- booklet: Methods of resolution
HT-66/05/004/A
3.4 Word
key
TEMP_INIT
TEMP_INIT = litps
Allows to define the initial field from which calculation in pointer under condition of
stationnarity is carried out.
3.4.1 Operand
EVOL_THER
EVOL_THER = temp
Name of the structure of data of the type
evol_ther
whose the field is extracted from
temperature from which the solution with the problem is calculated.
3.4.2 Operand
NUME_INIT
NUME_INIT =/nuini_evol
/
0
[DEFECT]
Sequence number of the field to be extracted from this structure of data.
Note:
For this type of calculation, there is no initial condition to define (it is defined with one
boundary condition on an edge of the field defined by the model). But, one can
nevertheless to carry out stationary calculation starting from a field of temperature already calculated
as solution of the problem for part of the load only. That can be useful
if the application of the totality of the loading makes convergence difficult. One
can then connect several resolutions with a loading which evolves/moves
gradually and to take as reiterated first of a calculation running the solution of calculation
precedent. Concretely, the key word then is used
TEMP_INIT
to define the field of
temperature with which one wants to initialize current calculation.
3.5 Word
key
CONVERGENCE
CONVERGENCE =
Allows to define the values associated with the criteria with convergence:
3.5.1 Operand
CRIT_TEMP_RELA
CRIT_TEMP_RELA =/1.e-3
/
testr
The algorithm continues the iterations as long as the relative variation of reiterated is higher than
testr
.
where
indicate the value of the temperature to node I for N
ième
iteration.
Code_Aster
®
Version
7.4
Titrate:
Operator
THER_NON_LINE_MO
Date:
20/01/05
Author (S):
C. DURAND
Key
:
U4.54.03-D
Page
:
5/6
Instruction manual
U4.5- booklet: Methods of resolution
HT-66/05/004/A
3.5.2 Operand
CRIT_ENTH_RELA
CRIT_ENTH_RELA =/1.e-2
/
testl
The algorithm continues the iterations as long as the relative variation of reiterated is higher than
testl
.
where
indicate the value of the enthalpy with N
ième
iteration with I
ième
not Gauss.
3.5.3 Operand
ITER_GLOB_MAXI
ITER_GLOB_MAXI =/10
/
iterl
The algorithm continues the external iterations as long as the iteration count external is
lower than
iterl
.
3.6 Word
key
SOLVEUR
SOLVEUR =
This key word factor is optional: it makes it possible to choose another solvor of resolution of system.
This operand is common to the whole of the total controls [U4.50.01].
3.7 Operand
TITRATE
TITRATE = title
Titrate that one wants to give to the result stored in
temp
structure of data of the type
evol_ther
[U4.03.01].
4 Modeling
The problems of nonlinear thermics in pointer and under condition of stationnarity can
to be treated with models using the finite elements 3D or plane 2D described in the documents
[U3.23.01] and [U3.24.01].
Code_Aster
®
Version
7.4
Titrate:
Operator
THER_NON_LINE_MO
Date:
20/01/05
Author (S):
C. DURAND
Key
:
U4.54.03-D
Page
:
6/6
Instruction manual
U4.5- booklet: Methods of resolution
HT-66/05/004/A
5 Examples
One presents below the main controls used to carry out a calculation of thermics
non-linear in pointer and under condition of stationnarity.
conduc =
DEFI_FONCTION (
NOM_PARA
=
“TEMP”,
VALE =
(
20.0,
95.0,
500.0, 325.0,
1000.0, 700.0
),
PROL_DROIT =
“CONSTANT”,
PROL_GAUCHE=
“CONSTANT”,
)
enthal =
DEFI_FONCTION
(
NOM_PARA
=
“TEMP”,
VALE =
(
0.0, 0.0,
500.0, 1.40E9,
510.0, 3.50E9,
1200.0, 4.70E9
),
PROL_DROIT =
“LINEAR”,
PROL_GAUCHE=
“LINEAR”,
)
chechmate =
DEFI_MATERIAU
(THER_NL=
_F (LAMBDA =
conduc,
BETA =
enthal
),)
…
chavi = AFFE_CHAM_NO
(MESH = mall,
SIZE = “DEPL_R”,
AFFE =_F (ALL = “YES”,
NOM_CMP = (“DX”, “DY”),
VALE_R = (1.0, 0.0))
tank = AFFE_CHAR_THER
(
MODEL =
model,
FLUX_REP =_F (GROUP_MA = penny,
FLUN = 5.E6),
CONVECTION =_F (SPEED =
chavi)
)
temple
=
THER_NON_LINE_MO
(
MODEL
=
model,
CHAM_MATER =
chmat,
EXCIT
=_F (LOAD =
tank
),
)
…
END ()