Sec05 Transient

8/12/2019 Sec05 Transient

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NAS104, Section 5, March 2004

Copyright2004 MSC.Software Corporation

SECTION 5

TRANSIENT THERMAL ANALYSIS(SOL 159)


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PROJECT 6QVOL(TIME)

This project comes from example 7c in the

MSC.Nastran Thermal User Guide.

Objective: apply time varying volumetric heating to a

single 1x1x1 CHEXA element.

HGEN=10.0

Also, convect to ambient temperature at 0 degree C

with a constant h of 100.0

Initially the solid is at zero degree


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PROJECT 6QVOL(TIME)

Specify QVOL as a function of

time Create a Non Spatial field named

qvol_time


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PROJECT 6QVOL(TIME)

Create a 1x1x1 solid.

IsoMesh the solid Hex8 topology

GEL = 1.0


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PROJECT 6QVOL(TIME)

Create a material

property set for

aluminum K

Cp

Rho


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PROJECT 6QVOL(TIME)

Change the Constitutive

Model to Heat generation

10.0 is the factor by whichthe heat generation is

multiplied


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PROJECT 6QVOL(TIME)

Create 3D element

property set

Aluminum

Solid 1


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PROJECT 6QVOL(TIME)

To create a time dependent

thermal load(e.g. applied

heating) it is necessary to first

create a time dependent load

case. When this is done theLBC form in MSC.Patran will

have the necessary entry lists

for the transient inputs.


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PROJECT 6QVOL(TIME)

The QVOL function is equal to

10000.0 * qvol_time(non spatial

time dependent field)


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PROJECT 6QVOL(TIME)

Create convection to ambient temperature Constant convection coefficient h=100

Ambient temperature is 0 C

No time function is used


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PROJECT 6QVOL(TIME)


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PROJECT 6QVOL(TIME)

Create a subcase under

Subcases A subcase is automatically created for

each load case that is created. They

both have the same name.

It may be necessary to change some of

the subcase settings, e.g. change someof the settings under Subcase

Parameters

It is possible to create a new subcase

using the available load cases. When

this is done specify the values for the

various subcase parameters.


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PROJECT 6QVOL(TIME)

Under Subcase Select

select the subcase named

tran for the transient

analysis


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PROJECT 6QVOL(TIME)

Access the transient

thermal analysis results

by attaching the .xdb

file to the MSC.Patrandatabase.


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PROJECT 6QVOL(TIME)

Create a plot of

temperature versus

time at a node(s)

After selecting theresult case

(SC1:TRAN), result

type(temperatures),

X: Global Variable

Time, then select

the second icon at

the top of the form

Target Entities


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PROJECT 6QVOL(TIME)


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PROJECT 6QVOL(TIME)

SOL 159

TIME 600

CEND

ANALYSIS = HEATTITLE = MSC/NASTRAN job created on 08-Jul-98 at

16:41:04

ECHO = SORT

MAXLINES = 999999999

SPC = 1

IC = 1

SUBCASE 1

$ Subcase name : tran

SUBTITLE=tranTSTEPNL = 1

DLOAD = 2

THERMAL(SORT2,PRINT)=ALL

FLUX(SORT2,PRINT)=ALL

Extracted from MSC.Nastran model .DAT file


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PROJECT 6QVOL(TIME)

PSOLID 1 1 0

CHEXA 1 1 1 2 4 3 5 6 + B

+ B 8 7

$ Referenced Material Records

$ Material Record : alum$ Description of Material : Date: 08-Jul-98 Time: 16:15:34

MAT4 1 204. 896. 2707. 10.

$ Nodes of the Entire Model

GRID 1 0. 0. 0.

GRID 2 1. 0. 0.

GRID 3 0. 1. 0.

GRID 4 1. 1. 0.

GRID 5 0. 0. 1.

GRID 6 1. 0. 1.GRID 7 0. 1. 1.

GRID 8 1. 1. 1.



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PROJECT 6QVOL(TIME)

$ Loads for Load Case : tran

TLOAD1 4 3 1

DLOAD 2 1. 1. 4

$ Fixed Temperatures of Load Set : conv

SPC 1 9 1 0.

$ Volumetric Heat Generation of Load Set : qvol

QVOL 3 10000. 1$ Scalar Points

SPOINT 9

$ Dynamic Load Table : qvol_timeTABLED1 1 + C

+ C 0. 0. 1000. 1. 2000. 0. 3000. 0. + D

+ D ENDT



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PROJECT 6QVOL(TIME)

$ Initial Temperatures from Temperature Load Sets

TEMP 1 9 0.

$ Default Initial Temperature

TEMPD 1 0.$ CHBDYG Surface Elements

CHBDYG 1 AREA4 + E

+ E 1 2 6 5

CHBDYG 2 AREA4 + F

+ F 3 7 8 4

CHBDYG 3 AREA4 + G

+ G 1 3 4 2

CHBDYG 4 AREA4 + H

+ H 2 4 8 6CHBDYG 5 AREA4 + I

+ I 6 8 7 5

CHBDYG 6 AREA4 + J

+ J 5 7 3 1



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PROJECT 6QVOL(TIME)

$ Convection to Ambient of Load Set : conv

PCONV 1 1001 0 0.

CONV 1 1 0 0 9CONV 2 1 0 0 9

CONV 3 1 0 0 9

CONV 4 1 0 0 9

CONV 5 1 0 0 9

CONV 6 1 0 0 9

$ Free Convection Heat Transfer CoefficientsMAT4 1001 100.



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PROJECT 6QVOL(TIME)

0

SUBCASE 1

POINT-ID = 3

T E M P E R A T U R E V E C T O R

TIME TYPE VALUE

0.0 S 0.0

1.000000E+01 S 2.061824E-03

2.000000E+01 S 8.236363E-033.000000E+01 S 1.851345E-02

4.000000E+01 S 3.288296E-02

5.000000E+01 S 5.133478E-02

6.000000E+01 S 7.385881E-02

7.000000E+01 S 1.004450E-01

8.000000E+01 S 1.310833E-01

9.000000E+01 S 1.657638E-01

1.000000E+02 S 2.044763E-01

1.100000E+02 S 2.472110E-01

TSTEPNL 1 6000 1.0 10 ADAPT UPW ++000001

++000001 ++000002

++000002 0

Deactivate the automatic adjustment(adaptivity)

Extract from MSC.Nastran ASCII Results File



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PROJECT 6QVOL(TIME)

$TITLE = MSC/NASTRAN JOB 49

$SUBTITLE=TRAN 50$LABEL = 51

$DISPLACEMENTS 52

$REAL OUTPUT 53

$SUBCASE ID = 1 54

$TIME = 0.5000000E+03 55

TEMP* 4 1 4.948450E+00 56

TEMP* 4 2 4.948450E+00 57

TEMP* 4 3 4.948450E+00 58

TEMP* 4 4 4.948450E+00 59TEMP* 4 5 4.948450E+00 60

TEMP* 4 6 4.948450E+00 61

TEMP* 4 7 4.948450E+00 62

TEMP* 4 8 4.948450E+00 63

TEMP* 4 9 0.000000E+00 64

Extract from MSC.Nastran ASCII Punch File

Results in SORT1 format in punch file.


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Perform Workshop 8 Transient Thermal in the

exercise workbook.

Perform Workshop 9 Transient Thermal Analysis of a

Cooling fin in the exercise workbook.

Perform Workshop 10 Holman example 4-14,

Radiation heating and cooling of ceramics in the

exercise workbook.

Perform Workshop 11 Heating a block of ice cream

in the exercise workbook

EXERCISES

Documents

Sec05 Transient