Ejemplo 51 calculo FEM con Adina
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Transcript of Ejemplo 51 calculo FEM con Adina
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7/23/2019 Ejemplo 51 calculo FEM con Adina
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Problem 51: Thermal FSI analysis of a pipe
ADINA R & D, Inc.51-1
Problem description
Consider a copper pipe containing water. Initially the water is at rest and the temperature of
the pipe and water is 20o C. At the start of the analysis, water at 90o C flows into the pipe with
a pressure drop of 60 Pa.
10
100
3
All lengths in mm
Initial temperature = 20 Co
Water in pipe, k- model used,
Copper pipe,
Inlet, prescribed normal-traction = 60 Pa,prescribed temperature = 90 C,
prescribed turbulence variables
o
E = 1.1 10 Pa 11
= 0.3
= 1.7 10 / C-3 o
CL
=4.7 10 N-s/m-4 2
= 980 kg/m3
= 8900 kg/m3
k=0.65W/m- Co
k=390W/m- Co
c = 4200J/kg- Cp o
c =380J/kg- Cp o
envo= 20 C
Convection boundary:
h= 10W/m - C2 o
We want to compute the stresses in the pipe.
The analysis is considered to be transient in the fluid and heat transfer analysis, but static in
the stress analysis.
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Problem 51: Thermal FSI analysis of a pipe
51-2 ADINA Primer
We will solve the problem using two analysis techniques:
TFSI (thermal FSI), with temperature coupling between the fluid and the solid.
BTFSI (thermal FSI, with boundary coupling), with temperature coupling at the fluid-
structure interface.
Here are diagrams schematically showing these analysis techniques:
TFSI:
FSIboundarycondition
E,
k,
k,
cp
cp
Fluidelementgroup
SolidelementgroupinADINACFD
SolidelementgroupinADINAstructures
BTFSI:
FSIboundarycondition
E,
k,
k,
cp
cp
Fluidelementgroup
Solidelementgroup
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Problem 51: Thermal FSI analysis of a pipe
ADINA R & D, Inc.51-3
Notice that in TFSI analysis, the fluid and structure are fully coupled. The fluid model
computes all of the heat transfer. The fluid model passes to the solid model the pressures on
the interface, and also the temperatures within the solid. The solid model passes to the fluid
model the displacements on the interface.
The element layout in the solid region of the fluid model can in general be different than the
element layout in the solid model.
In BTFSI analysis, one-way coupling is used. The fluid model passes to the solid model thepressures and temperatures on the interface. The solid model computes the heat transfer
within the solid.
In this problem solution, we will demonstrate the following topics that have not been
presented in previous problems:
$Performing a TFSI analysis (full coupling)
$Performing a BTFSI analysis (one-way coupling)
Before you begin
Please refer to the Icon Locator Tables chapter of the Primer for the locations of all of the
AUI icons. Please refer to the Hints chapter of the Primer for useful hints.
This problem cannot be solved with the 900 nodes version of the ADINA System because the
900 nodes version of the ADINA System does not contain ADINA-FSI.
Much of the input for this problem is stored in the following files: prob51_1.in, prob51_2.in.
You need to copy these files from the folder samples\primer into a working directory or folder
before beginning this analysis.
Invoking the AUI and choosing the finite element program
Invoke the AUI and choose ADINA CFD from the Program Module drop-down list.
TFSI analysis
Model definition - fluid model
We have prepared a batch file (prob51_1.in) that defines the geometry of the entire model, as
well as most of the fluid model:
Transient analysis, FCBI-C elements, turbulence analysis, FSI analysis, iteration
tolerances.
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Problem 51: Thermal FSI analysis of a pipe
51-4 ADINA Primer
Geometry points, lines, surfaces.
Material models for fluid model, and for "solid" region within fluid model.
Boundary conditions.
Initial conditions for the temperature.
Time steps, time functions and inlet boundary conditions. Twenty time steps of size 0.1are used. The turbulence load is defined in terms of a velocity of 1.0 m/s and a length of
0.02 m (the pipe diameter). The normal traction load of 60 Pa is chosen so that the
computed fluid velocity is on the order of 1 m/s.
Element groups and meshing.
Choose FileOpen Batch, navigate to the working directory or folder, select the file
prob51_1.in and click Open. The graphics window should look something like this:
D C B
CD CD CD CD CD CD CD CD
CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD
CD CD CD CD
BBBBBBBB
BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB
BBBB
V2
V3
P k
BCD
WA L FS I C NV
B - - 3C - 2 -
D 1 - -
TIME 2.000
X Y
Z
PRESCRIBEDNORMAL_TRACTION
TIME 2.000
60.00
PRESCRIBEDTEMPERATURE
TIME 2.000
90.00
PRESCRIBEDTURBULENCE_K
TIME 2.000
0.0009375
PRESCRIBEDTURBULENCEEPSILON
TIME 2.000
0.004784
Thermal FSI:Choose ModelFlow Assumptions, set "Thermal Coupling" to "Whole Solid
Domain" and click OK.
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Problem 51: Thermal FSI analysis of a pipe
ADINA R & D, Inc.51-5
Generating the ADINA CFD data file
Click the Save icon and save the database to file prob51_f. Click the Data File/Solution
icon , set the file name to prob51_f, uncheck the Run Solution button and click Save.
Model definition - solid model
We have prepared a batch file (prob51_2.in) that defines the solid model:
New database.
Current FE program set to ADINA Structures.
FSI analysis
Geometry points, lines, surfaces. The same geometry is used for the fluid and solid
models.
Boundary conditions.
Initial conditions for the temperature. Note that the initial conditions for the temperaturemust be specified both in the fluid model and in the solid model.
Material model. An elastic material with coefficient of thermal expansion is used.
Element group and meshing. In this case, the same element layout is used in the solid
region of the fluid model, and for the solid model. But 4-node elements are used in the
solid region of the fluid model, and 9-node elements are used in the solid model.
Dat file prob51_a.dat
Notice that there is no time stepping information defined in the solid model.
Choose File
Open Batch, navigate to the working directory or folder, select the fileprob51_2.in and click Open. The graphics window should look something like the figure on
the next page.
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Problem 51: Thermal FSI analysis of a pipe
51-6 ADINA Primer
B
B
BBBB
BBBB
BBB
BBB
U2
U3
B -
TIME 1.000
X Y
Z
Choose FileSave As and save the database to file prob51_a.
Running ADINA-FSI
Choose SolutionRun ADINA-FSI, click the Start button, select file prob51_f, then hold
down the Ctrl key and select file prob51_a. The File name field should display both file
names in quotes. Then click Start.
ADINA-FSI runs for 20 time steps. When ADINA-FSI is finished, close all open dialog
boxes, and set the Program Module to Post-Processing (you can discard all changes). Now
click the Open icon and open porthole file prob51_f.
Post-processing - fluid model
Click the Quick Vector Plot icon and click the Group Outline icon . The graphics
window should look something like the top figure on the next page.
The velocity is comparable to the velocity used in the turbulence load specifications.
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Problem 51: Thermal FSI analysis of a pipe
ADINA R & D, Inc.51-7
TIME 2.000
X Y
Z
VELOCITY
TIME 2.000
0.9608
0.9450
0.8750
0.8050
0.7350
0.6650
0.5950
0.5250
Now click the Clear Vector Plot icon , click the Create Band Plot icon , set the Band
Plot Variable to (Temperature:TEMPERATURE) and click OK. The graphics window shouldlook something like this:
TIME 2.000
X Y
Z
TEMPERATURE
TIME 2.000
89.70
89.10
88.50
87.90
87.3086.70
86.10
MAXIMUM90.00
NODE 143
MINIMUM85.60
NODE 1412
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Problem 51: Thermal FSI analysis of a pipe
51-8 ADINA Primer
Since the temperatures are all near 90o, the bands do not show lower temperatures. Click the
Modify Band Plot icon , click the Band Table ... button, set the Minimum to 20 and click
OK twice to close both dialog boxes. The graphics window should look something like this:
TIME 2.000
X Y
Z
TEMPERATURE
TIME 2.000
85.00
75.00
65.00
55.00
45.00
35.00
25.00
MAXIMUM90.00
NODE 143
MINIMUM85.60
NODE 1412
Now click the First Solution icon . The graphics window should look something like the
figure on the next page.
As you click the Next Solution icon repeatedly, you should see the temperature increase
rapidly in the water in the pipe, and more slowly in the pipe wall. You also should notice the
pipe wall moving outwards.
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Problem 51: Thermal FSI analysis of a pipe
ADINA R & D, Inc.51-9
TIME 0.1000
X Y
Z
TEMPERATURE
TIME 0.1000
85.00
75.00
65.00
55.00
45.00
35.00
25.00
MAXIMUM90.00
NODE 6
MINIMUM20.00
NODE 1412
Post-processing - solid model
Click the New icon (you can discard all changes), then click the Open icon and open
porthole file prob51_a. Then click the First Solution icon , click the Create Band Plot
icon , set the Band Plot Variable to (Temperature:ELEMENT_TEMPERATURE) and
click OK. The graphics window should look something like the top figure on the next page.
When you click the Next Solution icon several times, you can see the temperature rising
in the pipe wall.
Now click the First Solution icon , click the Modify Band Plot icon , set the variable
to (Strain:THERMAL_STRAIN) and click OK. Unfortunately the range of the band table is
not reset. Click the Modify Band Plot icon , click the Band Table ... button, set the
Minimum and Maximum to Automatic and click OK twice to close both dialog boxes. The
graphics window should look something like the bottom figure on the next page.
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Problem 51: Thermal FSI analysis of a pipe
51-10 ADINA Primer
TIME 0.1000
X Y
Z
ELEMENTTEMPERATURE
RST CALC
TIME 0.1000
85.00
75.00
65.00
55.00
45.00
35.00
25.00
MAXIMUM89.38
EG 1, EL 3, IPT 13 (76.93)
MINIMUM20.00
EG 1, EL 298, IPT 31
TIME 0.1000
X Y
Z
THERMAL_STRAIN
RST CALC
TIME 0.1000
0.1040
0.0880
0.0720
0.0560
0.0400
0.0240
0.0080
MAXIMUM0.1180EG 1, EL 3, IPT 13 (0.09682)
MINIMUM1.827E-10
EG 1, EL 298, IPT 31 (1.837E-10)
Note that the maximum thermal strain of 0.1180 is very close to the value obtained from the
formula 0 3( ) 1.7 10 (90 20) 0.119
= = .
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Problem 51: Thermal FSI analysis of a pipe
ADINA R & D, Inc.51-11
As you click the Next Solution icon repeatedly, you should see the thermal strain
increasing in the pipe wall.
Now click the First Solution icon , click the Clear Band Plot icon and the Quick
Band Plot icon . The graphics window should look something like this:
TIME 0.1000
X Y
Z
EFFECTIVESTRESS
RST CALC
TIME 0.1000
1.040E+10
8.800E+09
7.200E+09
5.600E+09
4.000E+09
2.400E+09
8.000E+08
MAXIMUM1.132E+10
EG 1, EL 3, IPT 13 (8.749E+09)
MINIMUM1.645E+07
EG 1, EL 54, IPT 12 (2.059E+07)
Again, you can click the Next Solution icon repeatedly to see the stress response. When
you click the Last Solution icon , the graphics window should look something like the
figure on the next page.
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Problem 51: Thermal FSI analysis of a pipe
51-12 ADINA Primer
TIME 2.000
X Y
Z
EFFECTIVESTRESS
RST CALC
TIME 2.000
1.040E+10
8.800E+09
7.200E+09
5.600E+09
4.000E+09
2.400E+09
8.000E+08
MAXIMUM1.278E+10
EG 1, EL 255, IPT 12
MINIMUM1.270E+10
EG 1, EL 247, IPT 31
BTFSI analysis
Model definition - fluid model
We will use the TFSI fluid model as the basis of the BTFSI fluid model.
Set the Program Module to ADINA CFD (you can discard all changes) and choose database
file prob51_f.idb from the recent file list near the bottom of the File menu.
Heading:Choose ControlHeading, set the Heading to "Primer problem 51: Thermal FSI
analysis of a pipe - BTFSI - fluid model" and click OK.
Thermal FSI:Choose ModelFlow Assumptions, set "Thermal Coupling" to "Boundary,
with Temperature Applied to Solid" and click OK.
Removing the solid element group:In the BTFSI fluid model, we don't need to model the pipe
wall in the fluid model. Click the Define Element Groups icon , delete group 2 and click
OK. Click the Special Boundary Conditions icon , delete boundary condition 3 and click
OK. After you click the Redraw icon , the graphics window should look something like
the figure on the next page.
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Problem 51: Thermal FSI analysis of a pipe
ADINA R & D, Inc.51-13
C B
BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BCBC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC BC
V2
V3
P k
BC
WAL FSI
B - 2C 1 -
TIME 2.000
X Y
Z
PRESCRIBEDNORMAL_TRACTION
TIME 2.000
60.00
PRESCRIBEDTEMPERATURE
TIME 2.000
90.00
PRESCRIBEDTURBULENCE_K
TIME 2.000
0.0009375
PRESCRIBEDTURBULENCEEPSILON
TIME 2.000
0.004784
Choose FileSave As and save the database to file prob51b_f. Click the Data File/Solution
icon , set the file name to prob51b_f, uncheck the Run Solution button and click Save.
Model definition - solid model
We will use the TFSI solid model as the basis of the BTFSI solid model.
Choose database file prob51_a.idb from the recent file list near the bottom of the File menu
(you can discard all changes).
Heading:Choose ControlHeading, set the Heading to "Primer problem 51: Thermal FSI
analysis of a pipe - BTFSI - solid model" and click OK.
Thermal analysis: Choose ControlTMC Model, set the "Type of Solution" to "TMC
Iterative Coupling", then click the ... button to the right of that field. Set the "Analysis Type"to "Transient" and click OK twice to close both dialog boxes.
Time stepping:Choose ControlTime Step, set the first row of the table to 20, 0.1, then click
OK.
TMC material:Click the Manage Materials icon , then click the TMC Material button.
Click the "k isotropic, c constant" button and add material 1. Set the Thermal Conductivity to
386, the Heat Capacity/Mass to 380, the Density to 8900 and click OK, then click Close twice
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Problem 51: Thermal FSI analysis of a pipe
51-14 ADINA Primer
to close all dialog boxes.
Convection boundary condition: Click the Apply Load icon , set the Load Type to
Convection and click the Define... button. Add convection load 1 and click the ... button to
the right of the Convection Property field. Add convection property 1, set the Convection
Coefficient to 10 and click OK. Then, in the Define Convection Load dialog box, set the
Environment Temperature to 20, set the Convection Property to 1 and click OK. In the Apply
Load dialog box, set the "Apply to" field to Line, set the Line Number to 5 in the first row of
the table and click OK.
After you click the Redraw icon , the graphics window should look something like this:
B
B
BBBB
BBBB
BBB
BBB
U2
U3
B -
TIME 2.000
X Y
Z
PRESCRIBEDCONVECTIONTEMPERATURE
TIME 2.000
20.00
Click the Save icon to save the database to file prob51_a. Click the Data File/Solution
icon , set the file name to prob51b_a, uncheck the Run Solution button and click Save.
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Problem 51: Thermal FSI analysis of a pipe
ADINA R & D, Inc.51-15
Running ADINA-FSI
Choose SolutionRun ADINA-FSI, click the Start button, select file prob51b_f, then hold
down the Ctrl key and select file prob51b_a. The File name field should display both file
names in quotes. Set the "Run" field to "Fluid Only", then click Start.
After the ADINA-FSI run finishes (in 20 steps), close all open dialog boxes, choose
SolutionRun ADINA-FSI, click the Start button, select file prob51b_f, then hold down
the Ctrl key and select file prob51b_a. The File name field should display both file names inquotes. Set the "Run" field to "Structure Only", then click Start.
When ADINA-FSI is finished, close all open dialog boxes, and set the Program Module to
Post-Processing (you can discard all changes). Now click the Open icon and open
porthole file prob51b_f.
Click the Quick Vector Plot icon and click the Group Outline icon . The graphics
window should look something like this:
TIME 2.000
X Y
Z
VELOCITY
TIME 2.000
1.031
0.980
0.910
0.840
0.770
0.700
0.630
0.560
The velocity is almost the same as in the TFSI analysis.
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Problem 51: Thermal FSI analysis of a pipe
51-16 ADINA Primer
Now click the Clear Vector Plot icon , click the First Solution icon , click the Create
Band Plot icon , set the Band Plot Variable to (Temperature:TEMPERATURE) and click
OK. The graphics window should look something like this:
TIME 0.1000
X Y
Z
TEMPERATURE
TIME 0.1000
85.00
75.00
65.00
55.00
45.00
35.00
25.00
MAXIMUM90.00
NODE 7
MINIMUM20.00
NODE 1101
The pipe wall boundary now acts as an insulated boundary (zero heat flow through the
boundary).
As you click the Next Solution icon repeatedly, you should see the temperature increase
rapidly in the water in the pipe. The temperature rises more slowly at the pipe wall boundary
because the fluid moves more slowly there. You will also notice that the fluid domain does
not change.
Post-processing - solid model
Click the New icon (you can discard all changes and continue), then click the Open icon
and open porthole file prob51b_a. Then click the First Solution icon , click the
Create Band Plot icon , set the Band Plot Variable to (Temperature:
ELEMENT_TEMPERATURE) and click OK. The graphics window should look something
like the figure on the next page.
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Problem 51: Thermal FSI analysis of a pipe
ADINA R & D, Inc.51-17
TIME 0.1000
X Y
Z
ELEMENTTEMPERATURE
RST CALC
TIME 0.1000
81.00
72.00
63.00
54.00
45.00
36.00
27.00
MAXIMUM86.87
EG 1, EL 3, IPT 13 (83.57)
MINIMUM20.00
EG 1, EL 298, IPT 31
When you click the Next Solution icon several times, you can see the temperature rising
in the pipe wall. The temperature solution looks very similar to that from the TFSI analysis.
Now click the First Solution icon , click the Clear Band Plot icon , click the Create
Band Plot icon , set the variable to (Strain:THERMAL_STRAIN) and click OK. The
graphics window should look something like the top figure on the next page.
Again the thermal strain is very similar to the thermal strain from the TFSI analysis.
Now click the First Solution icon , click the Clear Band Plot icon and click the Quick
Band Plot icon . The graphics window should look something like the bottom figure on
the next page.
Again the effective stress is very similar to that from the TFSI analysis.
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Problem 51: Thermal FSI analysis of a pipe
51-18 ADINA Primer
TIME 0.1000
X Y
Z
THERMAL_STRAIN
RST CALC
TIME 0.1000
0.1040
0.0880
0.0720
0.0560
0.0400
0.0240
0.0080
MAXIMUM0.1137
EG 1, EL 3, IPT 13 (0.1081)
MINIMUM1.167E-08
EG 1, EL 298, IPT 31 (1.171E-08)
TIME 0.1000
X Y
Z
EFFECTIVESTRESS
RST CALC
TIME 0.1000
7.000E+09
6.000E+09
5.000E+09
4.000E+09
3.000E+09
2.000E+09
1.000E+09
MAXIMUM7.406E+09
EG 1, EL 3, IPT 13 (6.715E+09)
MINIMUM2.952E+08
EG 1, EL 45, IPT 11 (2.914E+08)
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Problem 51: Thermal FSI analysis of a pipe
ADINA R & D, Inc.51-19
When you click the Last Solution icon , the graphics window should look something like
this:
TIME 2.000
X Y
Z
EFFECTIVESTRESS
RST CALCTIME 2.000
7.000E+09
6.000E+09
5.000E+09
4.000E+09
3.000E+09
2.000E+09
1.000E+09
MAXIMUM1.309E+10
EG 1, EL 33, IPT 12
MINIMUM1.309E+10
EG 1, EL 28, IPT 31
Exiting the AUI:Choose FileExit to exit the AUI. You can discard all changes.
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Problem 51: Thermal FSI analysis of a pipe
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