JEC COMPOSITES MAGAZINE - Issue #105 - June 2016 - 28

flow simulation

Tab. 3: Comparison of several parameters and results of the simulations conducted with various element sizes

Distance from injection 10 cm
Time of flow front arrival (s)

Mesh size
2 mm

5 mm

10 mm

20 mm

2.49

2.53

2.60

2.71

1.61

4.42

8.84

Error to the 2 mm mesh (%)
Number of elements in the model

2000

800

400

200

Ratio of computation time compared
to the 2 mm mesh calculation

1/1

1/6.5

1/30

1/124

Mesh size sensitivity
of the method

Fig. 2: Fluid fraction after 95 seconds of injection
in single- and dual-scale simulations (top view of
the cavity)

results of both simulations are presented
in figure 2.
Figure 2 presents a mapping of the fluid
fraction after 95 seconds of injection. The
predictions of the single-scale simulation
state that the part is fully filled with the
resin, but in the dual-scale simulation,
it can be observed that the tows are
not saturated at the end of the cavity.
Moreover, the reactive computation
reveales the imminent resin solidification in the tows in this region, making
impossible a further filling even with a
longer injection time. Thus the dual-scale
reactive simulation demonstrates that the
injection parameters determined with a
classical single-scale simulation do not
allow to fill the part properly.

Fig. 3: Evolution of pressure at different locations
in the cavity for different mesh sizes

One of the claims of the developed technique is its ability to treat dual-scale flow
with the same degree of precision for various element sizes. Therefore, isothermal
1D filling simulations with constant inlet
pressure were conducted using meshes
with element sizes ranging from 2 mm
to 20 mm. The characteristics of the
textile and the processing conditions are
described in table 2.
The length of the unsaturated area was
measured in the simulations conducted
with different mesh sizes. It was estimated at 6 mm for the 2-mm mesh and 5.7
mm for the 20-mm mesh. These values
are very close, although, for the 20-mm
mesh, the elements are three times bigger
than the unsaturated area. This highlights
the ability of the model to track the unsaturated area accurately, even with large
elements.
Furthermore, tracking pressure evolution
and macroscopic flow front arrival at specific positions in the cavity makes it possible to determine if the resin is spread
the same way between the macro- and
micro-scale with a small or a large mesh.
Figure 3 shows the evolution of pressure
at different locations in the cavity.
Figure 3 shows that the evolution of
pressure is very similar for mesh sizes
2, 5 and 10 mm. Table 3 presents the
flow front arrival time at 10 cm from the
injection line for the different mesh sizes.
These arrival times are compared to the
one obtained with the 2-mm mesh and
the relative errors are presented.

28 jec composites magazine / No105 June 2016

Table 3 shows that the error on the macroscopic flow front arrival is increasing
with increasing mesh size. However, even
when dividing the number of macroscopic elements in the model by a factor of
10, this error remains under 10%. Furthermore, the method remains accurate
in a range of 10% for elements more than
three times bigger than the unsaturated
area. This demonstrates the flexibility
of the proposed model and its ability to
treat an isothermal injection case accurately for several element sizes. Finally,
the advantages of the new numerical
method in terms of CPU time reduction
can be noticed. In the case of the 10-mm
mesh, the computation time is reduced
by a factor 30 while the error on the time
of flow front arrival stays smaller than 5%
compared to the 2-mm mesh.

Conclusions
Dual-scale numerical injection methods
make it possible to predict manufacturing defects encountered in high-speed
RTM processes as intra-tow porosities.
The developed approach demonstrates
an interesting ability to treat dual-scale
injection cases: the numerical strategy
combined with its weak sensitivity to
mesh size leads to computation times
similar to regular single-scale approaches.
The next step will be to validate the
approach by confronting the numerical
results with experimental results before
industrial implementation in PAM-RTM
from ESI's PAM-COMPOSITES simulation suite. n
More information:
www.esi-group.com/composites


http://www.esi-group.com/composites

Table of Contents for the Digital Edition of JEC COMPOSITES MAGAZINE - Issue #105 - June 2016

Cover
Edito
Point of view: eastern promises
Contents
COMPANY & BUSINESS
APPLICATIONS
Quickstep contract to open up South Korean automotive market
Development
Design methods
Agenda of Events
APPLICATIONS
Aeronautics
Kayak
Robot
MARKET
Software
Brazil
FEATURE SIMULATION
Flow simulation
Microstructure
Damage
3D-printing
Data
Data
RESEARCH & DEVELOPMENT
Smart composites
Laser cutting
TECHNOLOGY & INNOVATIONS
Testing
Efficiency
Index
In the world
JEC COMPOSITES MAGAZINE - Issue #105 - June 2016 - Cover
JEC COMPOSITES MAGAZINE - Issue #105 - June 2016 - 2
JEC COMPOSITES MAGAZINE - Issue #105 - June 2016 - Edito
JEC COMPOSITES MAGAZINE - Issue #105 - June 2016 - Point of view: eastern promises
JEC COMPOSITES MAGAZINE - Issue #105 - June 2016 - 5
JEC COMPOSITES MAGAZINE - Issue #105 - June 2016 - Contents
JEC COMPOSITES MAGAZINE - Issue #105 - June 2016 - 7
JEC COMPOSITES MAGAZINE - Issue #105 - June 2016 - Quickstep contract to open up South Korean automotive market
JEC COMPOSITES MAGAZINE - Issue #105 - June 2016 - 9
JEC COMPOSITES MAGAZINE - Issue #105 - June 2016 - Development
JEC COMPOSITES MAGAZINE - Issue #105 - June 2016 - 11
JEC COMPOSITES MAGAZINE - Issue #105 - June 2016 - Design methods
JEC COMPOSITES MAGAZINE - Issue #105 - June 2016 - 13
JEC COMPOSITES MAGAZINE - Issue #105 - June 2016 - Agenda of Events
JEC COMPOSITES MAGAZINE - Issue #105 - June 2016 - 15
JEC COMPOSITES MAGAZINE - Issue #105 - June 2016 - Ad1
JEC COMPOSITES MAGAZINE - Issue #105 - June 2016 - Ad2
JEC COMPOSITES MAGAZINE - Issue #105 - June 2016 - Aeronautics
JEC COMPOSITES MAGAZINE - Issue #105 - June 2016 - Kayak
JEC COMPOSITES MAGAZINE - Issue #105 - June 2016 - Robot
JEC COMPOSITES MAGAZINE - Issue #105 - June 2016 - Software
JEC COMPOSITES MAGAZINE - Issue #105 - June 2016 - 20
JEC COMPOSITES MAGAZINE - Issue #105 - June 2016 - 21
JEC COMPOSITES MAGAZINE - Issue #105 - June 2016 - 22
JEC COMPOSITES MAGAZINE - Issue #105 - June 2016 - 23
JEC COMPOSITES MAGAZINE - Issue #105 - June 2016 - Brazil
JEC COMPOSITES MAGAZINE - Issue #105 - June 2016 - 25
JEC COMPOSITES MAGAZINE - Issue #105 - June 2016 - Flow simulation
JEC COMPOSITES MAGAZINE - Issue #105 - June 2016 - 27
JEC COMPOSITES MAGAZINE - Issue #105 - June 2016 - 28
JEC COMPOSITES MAGAZINE - Issue #105 - June 2016 - Microstructure
JEC COMPOSITES MAGAZINE - Issue #105 - June 2016 - 30
JEC COMPOSITES MAGAZINE - Issue #105 - June 2016 - Damage
JEC COMPOSITES MAGAZINE - Issue #105 - June 2016 - 32
JEC COMPOSITES MAGAZINE - Issue #105 - June 2016 - 33
JEC COMPOSITES MAGAZINE - Issue #105 - June 2016 - 3D-printing
JEC COMPOSITES MAGAZINE - Issue #105 - June 2016 - 35
JEC COMPOSITES MAGAZINE - Issue #105 - June 2016 - Data
JEC COMPOSITES MAGAZINE - Issue #105 - June 2016 - 37
JEC COMPOSITES MAGAZINE - Issue #105 - June 2016 - Data
JEC COMPOSITES MAGAZINE - Issue #105 - June 2016 - 39
JEC COMPOSITES MAGAZINE - Issue #105 - June 2016 - 40
JEC COMPOSITES MAGAZINE - Issue #105 - June 2016 - 41
JEC COMPOSITES MAGAZINE - Issue #105 - June 2016 - Smart composites
JEC COMPOSITES MAGAZINE - Issue #105 - June 2016 - 43
JEC COMPOSITES MAGAZINE - Issue #105 - June 2016 - 44
JEC COMPOSITES MAGAZINE - Issue #105 - June 2016 - 45
JEC COMPOSITES MAGAZINE - Issue #105 - June 2016 - Laser cutting
JEC COMPOSITES MAGAZINE - Issue #105 - June 2016 - 47
JEC COMPOSITES MAGAZINE - Issue #105 - June 2016 - 48
JEC COMPOSITES MAGAZINE - Issue #105 - June 2016 - 49
JEC COMPOSITES MAGAZINE - Issue #105 - June 2016 - 50
JEC COMPOSITES MAGAZINE - Issue #105 - June 2016 - Testing
JEC COMPOSITES MAGAZINE - Issue #105 - June 2016 - 52
JEC COMPOSITES MAGAZINE - Issue #105 - June 2016 - 53
JEC COMPOSITES MAGAZINE - Issue #105 - June 2016 - 54
JEC COMPOSITES MAGAZINE - Issue #105 - June 2016 - Efficiency
JEC COMPOSITES MAGAZINE - Issue #105 - June 2016 - 56
JEC COMPOSITES MAGAZINE - Issue #105 - June 2016 - Index
JEC COMPOSITES MAGAZINE - Issue #105 - June 2016 - In the world
JEC COMPOSITES MAGAZINE - Issue #105 - June 2016 - 59
JEC COMPOSITES MAGAZINE - Issue #105 - June 2016 - 60
https://www.nxtbook.fr/newpress/jeccomposites/jcm1911_Special_Issue2
https://www.nxtbook.fr/newpress/jeccomposites/jcm1911_131
https://www.nxtbook.fr/newpress/jeccomposites/jcm1909_130
https://www.nxtbook.fr/newpress/jeccomposites/jcm1907_129
https://www.nxtbook.fr/newpress/jeccomposites/jcm1905_128
https://www.nxtbook.fr/newpress/jeccomposites/jcm1903_Special_Issue1
https://www.nxtbook.fr/newpress/jeccomposites/jcm1903_127
https://www.nxtbook.fr/newpress/jeccomposites/jcm1901_126
https://www.nxtbook.fr/newpress/jeccomposites/jcm1811_125
https://www.nxtbook.fr/newpress/jeccomposites/jcm1810_124
https://www.nxtbook.fr/newpress/jeccomposites/jcm1808_123
https://www.nxtbook.fr/newpress/jeccomposites/jcm1807_122
https://www.nxtbook.fr/newpress/jeccomposites/jcm1805_121
https://www.nxtbook.fr/newpress/jeccomposites/jcm1804_120
https://www.nxtbook.fr/newpress/jeccomposites/jcm1803_119
https://www.nxtbook.fr/newpress/jeccomposites/jcm1802_119-Supplement_Innovation_Report
https://www.nxtbook.fr/newpress/jeccomposites/jcm1801_118
https://www.nxtbook.fr/newpress/jeccomposites/jcm1711_117
https://www.nxtbook.fr/newpress/jeccomposites/jcm1710_116
https://www.nxtbook.fr/newpress/jeccomposites/jcm1708_115
https://www.nxtbook.fr/newpress/jeccomposites/jcm1707_114
https://www.nxtbook.fr/newpress/jeccomposites/jcm1706_113
https://www.nxtbook.fr/newpress/jeccomposites/jcm1704_112
https://www.nxtbook.fr/newpress/jeccomposites/jcm1703_111
https://www.nxtbook.fr/newpress/jeccomposites/jcm1701_110
https://www.nxtbook.fr/newpress/jeccomposites/jcm1611_109
https://www.nxtbook.fr/newpress/jeccomposites/jcm1610_108
https://www.nxtbook.fr/newpress/jeccomposites/jcm1608_107
https://www.nxtbook.fr/newpress/jeccomposites/jcm1607_106
https://www.nxtbook.fr/newpress/jeccomposites/jcm1605_105
https://www.nxtbook.fr/newpress/jeccomposites/jcm1604_104
https://www.nxtbook.fr/newpress/jeccomposites/jcm1603_103
https://www.nxtbook.fr/newpress/jeccomposites/jcm1601_102
https://www.nxtbook.fr/newpress/jeccomposites/jcm1511_101
https://www.nxtbook.fr/newpress/jeccomposites/jcm1510_100
https://www.nxtbook.fr/newpress/jeccomposites/jcm1509_99
https://www.nxtbook.fr/newpress/jeccomposites/jcm1507_98
https://www.nxtbook.fr/newpress/jeccomposites/jcm1505_97
https://www.nxtbook.fr/newpress/jeccomposites/jcm1504_96
http://www.nxtbook.com/newpress/jeccomposites/jcm1503_95
http://www.nxtbook.com/newpress/jeccomposites/jcm1501_94
http://www.nxtbook.com/newpress/jeccomposites/jcm1412_93
http://www.nxtbook.com/newpress/jeccomposites/jcm1410_92
http://www.nxtbook.com/newpress/jeccomposites/jcm1409_91
http://www.nxtbook.com/newpress/jeccomposites/jcm1406_90
http://www.nxtbook.com/newpress/jeccomposites/jcm1405_89
http://www.nxtbook.com/newpress/jeccomposites/jcm1404_88
http://www.nxtbook.com/newpress/jeccomposites/jcm1403_87
http://www.nxtbook.com/newpress/jeccomposites/jcm1401_86
http://www.nxtbook.com/newpress/jeccomposites/jcm1311_85
http://www.nxtbook.com/newpress/jeccomposites/jcm1310_84
http://www.nxtbook.com/newpress/jeccomposites/jcm1308_83
http://www.nxtbook.com/newpress/jeccomposites/jcm1307_82
http://www.nxtbook.com/newpress/jeccomposites/jcm1305_81
http://www.nxtbook.com/newpress/jeccomposites/jcm1304_80
http://www.nxtbook.com/newpress/jeccomposites/jcm1303_79
http://www.nxtbook.com/newpress/jeccomposites/jcm1301_78
http://www.nxtbook.com/newpress/jeccomposites/jcm1212_77
http://www.nxtbook.com/newpress/jeccomposites/jcm1210_76
http://www.nxtbook.com/newpress/jeccomposites/jcm1208_75
http://www.nxtbook.com/newpress/jeccomposites/jcm1207_74
http://www.nxtbook.com/newpress/jeccomposites/jcm1206_73
http://www.nxtbook.com/newpress/jeccomposites/jcm1204_72
http://www.nxtbook.com/newpress/jeccomposites/jcm1203_71
http://www.nxtbook.com/newpress/jeccomposites/jcm1201_70
http://www.nxtbook.com/newpress/jeccomposites/jcm1111_69
http://www.nxtbook.com/newpress/jeccomposites/jcm1110_68
http://www.nxtbook.com/newpress/jeccomposites/jcm1108_67
http://www.nxtbook.com/newpress/jeccomposites/jcm1107_66
http://www.nxtbook.com/newpress/jeccomposites/jcm1105_65
http://www.nxtbook.com/newpress/jeccomposites/jcm1104_64
http://www.nxtbook.com/newpress/jeccomposites/jcm1103_63
http://www.nxtbook.com/newpress/jeccomposites/jcm1101_62
http://www.nxtbook.com/newpress/jeccomposites/jcm1011_61
http://www.nxtbook.com/newpress/jeccomposites/jcm1010_60
http://www.nxtbook.com/newpress/jeccomposites/jcm1009_59
http://www.nxtbook.com/newpress/jeccomposites/jcm1006_58
http://www.nxtbook.com/newpress/jeccomposites/jcm1005_57
http://www.nxtbook.com/newpress/jeccomposites/jcm1004_56
http://www.nxtbook.com/newpress/jeccomposites/jcm1003_55
http://www.nxtbook.com/newpress/jeccomposites/jcm1001_54
http://www.nxtbook.com/newpress/jeccomposites/jcm0911_53
http://www.nxtbook.com/newpress/jeccomposites/jcm0910_52
http://www.nxtbook.com/newpress/jeccomposites/jcm0909_51
http://www.nxtbook.com/newpress/jeccomposites/jcm0907-08_50
http://www.nxtbook.com/newpress/jeccomposites/jcm0906_49
http://www.nxtbook.com/newpress/jeccomposites/jcm0904_48
http://www.nxtbook.com/newpress/jeccomposites/jcm0903_47
http://www.nxtbook.com/newpress/jeccomposites/jcm0901_46
http://www.nxtbook.com/newpress/jeccomposites/jcm0811_45
http://www.nxtbook.com/newpress/jeccomposites/jcm0810_44
http://www.nxtbook.com/newpress/jeccomposites/jcm0809_43
http://www.nxtbook.com/newpress/jeccomposites/jcm0807_42
http://www.nxtbook.com/newpress/jeccomposites/jcm0806_41
http://www.nxtbook.com/newpress/jeccomposites/jcm0805_40
http://www.nxtbook.com/newpress/jeccomposites/jcm0803_39
http://www.nxtbook.com/newpress/jeccomposites/jcm0801_38
http://www.nxtbook.com/newpress/jeccomposites/jcm0712_37
http://www.nxtbook.com/newpress/jeccomposites/jcm0710_36
http://www.nxtbook.com/newpress/jeccomposites/jcm0709_35
http://www.nxtbook.com/newpress/jeccomposites/jcm0707_34
http://www.nxtbook.com/newpress/jeccomposites/jcm0706_33
http://www.nxtbookMEDIA.com