ejemplo 51 calculo fem con adina

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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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