Code_Aster
®
Version
5.0
Titrate:
TTLV301 Parallelepiped subjected to a temperature imposed on its faces
Date:
20/09/02
Author (S):
C. DURAND,
E. SCREWS, F. LEBOUVIER
Key
:
V4.25.301-A
Page:
1/6
Manual of Validation
V4.25 booklet: Transitory thermics of the voluminal structures
HT-66/02/001/A
Organization (S):
EDF/AMA, EDF/UTO/LOCATED, Delta CAD
Manual of Validation
V4.25 booklet: Transitory thermics of the voluminal structures
V4.25.301 document
TTLV301 - Parallelepiped subjected to one
temperature imposed on its faces
Summary:
This test results from the validation independent of version 3 in linear transitory thermics.
It is about a voluminal problem represented by only one modeling (3D).
The functionalities tested are as follows:
·
voluminal thermal element,
·
transitory algorithm of thermics,
·
limiting conditions: imposed temperature.
The results are compared with an analytical solution.
Code_Aster
®
Version
5.0
Titrate:
TTLV301 Parallelepiped subjected to a temperature imposed on its faces
Date:
20/09/02
Author (S):
C. DURAND,
E. SCREWS, F. LEBOUVIER
Key
:
V4.25.301-A
Page:
2/6
Manual of Validation
V4.25 booklet: Transitory thermics of the voluminal structures
HT-66/02/001/A
1
Problem of reference
1.1 Geometry
X
Y
L
1
L
3
L
2
Z
Dimensions of the parallelepiped: 2m X 3.2m X 4m
- L
1
= 1.0 m
- L
2
= 1.6 m
- L
3
= 2.0 m
Not O (0., 0., 0.)
Not H (0.5, 0.8, 1.0)
O
H
1.2
Properties of material
=
1. W/m °C
thermal conductivity
C
p
=
1. J/kg °C
specific heat
1.
kg/m
3
mass
voluminal
1.3
Boundary conditions and loadings
Temperature imposed on the 6 faces T = 2 °C = T
W
1.4 Conditions
initial
T (T = 0) = 1°C = T
O
Code_Aster
®
Version
5.0
Titrate:
TTLV301 Parallelepiped subjected to a temperature imposed on its faces
Date:
20/09/02
Author (S):
C. DURAND,
E. SCREWS, F. LEBOUVIER
Key
:
V4.25.301-A
Page:
3/6
Manual of Validation
V4.25 booklet: Transitory thermics of the voluminal structures
HT-66/02/001/A
2
Reference solution
2.1
Method of calculation used for the reference solution
(
)
(
) (
) (
)
(
)
(
)
(
)
T X y Z T
T
has
T
m
X
L
N
y
L
L
Z
L
has
T
T
m
N
L
m
N
L
W
m
N
nml
L
mnl
mnl
W
(,)
exp (
. ) .cos (
)
cos (
)
cos (
)
sin
sin
sin
=
+
-
-
-
-
=
-
-
-
-
-
-
-
=
=
=
1
1
1
2
1
2
3
0
3
2
1
2
2
1
2
2
1
2
64
2
1 2
1 2
1
2
1
2
2
1
2
2
1
(
)
(
)
(
)
2
2
1
2
2
1
2
2
1
2
2
1
2
2
2
3
2
=
-
+
-
+
-
=
mnl
p
m
L
N
L
L
L
C
.
The values of reference are obtained with
m N L
= = =
100.
2.2
Results of reference
Temperature at the points: O (0,0,0) and H (0.5, 0.8, 1.)
2.3
Uncertainty on the solution
Analytical solution.
2.4 References
bibliographical
[1]
Mr. J Chang, L.C Chow, W.S Chang, “Improved alternating direction implicit for solving
transient three dimensional heat dissemination problems ", Numerical Heat Transfer, flight 19, p 69-
84, 1991.
Code_Aster
®
Version
5.0
Titrate:
TTLV301 Parallelepiped subjected to a temperature imposed on its faces
Date:
20/09/02
Author (S):
C. DURAND,
E. SCREWS, F. LEBOUVIER
Key
:
V4.25.301-A
Page:
4/6
Manual of Validation
V4.25 booklet: Transitory thermics of the voluminal structures
HT-66/02/001/A
3 Modeling
With
3.1
Characteristics of modeling
3D (HEXA27)
Modeling 1/8 of the parallelepiped
Mesh:
- 5 elements according to X
- 8 elements following y
- 10 elements according to Z
Limiting conditions:
- faces [ABCD], [BEFC], [DCFG]: T = 2°C
- faces [ABEO], [AOGD], [OEFG]:
= 0.
Points
X
y
Z
Node
O
0.00
0.00
0.00
N5
H
0.50
0.80
1.00
N1075
C
X
y
L
1
L
3
Z
L
2
With
B
E
D
G
F
O
H
3.2
Characteristics of the mesh
A number of nodes:
3927
A number of meshs and types: 400 HEXA27
3.3 Functionalities
tested
Controls
AFFE_MODELE
THERMICS
3D
AFFE_CHAR_THER
TEMP_IMPO
THER_LINEAIRE
TEMP_INIT
VALE
LIST_INST
RECU_CHAMP
INST
3.4 Remarks
The limiting condition
= 0. are implicit on the free edges.
Discretization of time: 24 intervals between 0. and 1.2 seconds:
T = 0.00
with T = 0.02
: 4 0.005 seconds intervals.
T = 0.02
with T = 0.05
: 3 intervals of 0.01
seconds.
T = 0.05
with T = 0.15
: 4 0.025 seconds intervals.
T = 0.15
with T = 0.4
: 5 intervals of 0.05
seconds.
T = 0.4
with T = 1.2
: 8 intervals of 0.1
seconds.
Code_Aster
®
Version
5.0
Titrate:
TTLV301 Parallelepiped subjected to a temperature imposed on its faces
Date:
20/09/02
Author (S):
C. DURAND,
E. SCREWS, F. LEBOUVIER
Key
:
V4.25.301-A
Page:
5/6
Manual of Validation
V4.25 booklet: Transitory thermics of the voluminal structures
HT-66/02/001/A
4
Results of modeling A
4.1 Values
tested
Identification
Reference
Aster %
difference
Tolerance
Not O
N5 (0., 0., 0.)
T = 0.1 S
1.05137
1.04934
-
0.193
1%
T = 0.2 S
1.24768
1.24181
-
0.471
1%
T = 0.3 S
1.45136
1.44378
-
0.522
1%
T = 0.5 S
1.73684
1.72955
-
0.420
1%
T = 0.7 S
1.88010
1.87516
-
0.263
1%
T = 1.0 S
1.96406
1.96191
-
0.110
1%
T = 1.2 S
1.98398
1.98282
-
0.059
1%
Not H
N1075 (0.5, 0.8, 1.0)
T = 0.1 S
1.33579
1.32490
-
0.816
1%
T = 0.2 S
1.61081
1.60337
-
0.462
1%
T = 0.3 S
1.75959
1.75424
-
0.304
1%
T = 0.5 S
1.90017
1.89718
-
0.157
1%
T = 0.7 S
1.95657
1.95478
-
0.091
1%
T = 1.0 S
1.98723
1.98646
-
0.039
1%
T = 1.2 S
1.99433
1.99391
-
0.021
1%
4.2 Parameters
of execution
Version: 5.03
Machine: SGI - ORIGIN 2000 - R12000
Overall dimension memory:
8 megawords
Time CPU To use: 16.36 seconds
Code_Aster
®
Version
5.0
Titrate:
TTLV301 Parallelepiped subjected to a temperature imposed on its faces
Date:
20/09/02
Author (S):
C. DURAND,
E. SCREWS, F. LEBOUVIER
Key
:
V4.25.301-A
Page:
6/6
Manual of Validation
V4.25 booklet: Transitory thermics of the voluminal structures
HT-66/02/001/A
5
Summary of the results
The results obtained are satisfactory. The maximum change obtained (0.816%), is located at the point H placed
halfway enters surface external and the center of the parallelepiped. At the end of 1.2s, this variation
decrease, the maximum obtained is then of 0.059% (not O: center parallelepiped).
This test made it possible to test in linear transient modeling 3D with meshs HEXA27.