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b.Thermal analysis

Problem 1: (1D conduction): For the composite wall idealized by the 1-D model shown in below,

determine the interface temperatures. For element 1, let K1= 5W/moC. For element 2, K2=10

W/moC and for element 3, K3= 15 W/m

oC. The left end has a constant temperature of 200

oC and

the right end has a constant temperature of 600o

C

T=200 oC T=600 oC A=.01m2

1 2 3

0.1m 0.1m 0.1m

Solution:

given:

T1 = 200oC T1 = 600

oC A=0.1m

2

K1= 5W/moC K2=10 W/m

oC K3= 15 W/m

oC

Finite Element Model

T1 T2 T3 T4

0.1m 0.1m 0.1m

I. PRE-PROCESSING STAGEStep 1:Setting the Preferences for GUI filtering

Ansys main Menu Preferences.

Selectthermal-OK

Step2 Defining Element Type

Ansys main Menu Pre processor

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Element type - Add /Edit /Delete- Add - Link - 2D conduction 32 -OK .close

Step3: Defining Real Constants

Ansys Main Menu Pre processor.

Real constants- Add- OK-Real constant Set No:1

Cross sectional area 0.1- OK close

Step 4: Define material properties

Ansys Main Menu Pre processor

Material Properties -Material Models - Material Model - Material Model no:1- Thermal

Conductivity Isotropic- Conductivity For Material Number 1- Kxx-5- OK

Material- New Model-Define Material ID -2 OK Thermal-Conductivity Isotropic- Conductivity

For Material No:2 Kxx- 10-OK

Material- New Model-Define material ID -3- OK thermal-conductivity

Isotropic- Conductivity For Material No:3- Kxx- 15-OK- Close

Step 5: Create the Geometry of the Model

Ansys Main Menu-Preprocessor

Modeling-Create-Nodes-In Active CS-X,Y,Z location is CS

0,0,0 Apply(First Node is created)

0.1,0,0 Apply (Second Node is Created)

0.2,0,0 Apply (Third Node is created)

0.3,0,0 Apply (Fourth Node is created)-OK

Create-Elements-Element Attributes-Select Material Number-1-Real Auto Numbered-Thru Nodes-

Pick 1,2 Apply (Element 1 is created).

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Element Attributes-Select Material Number -2-Real Constant Set Number-1-Real constant-Auto

numbered- Thru Nodes-Pick 2,3 Apply (Element 2 is created).

Element Attributes-Select Material Number-3-ReaI Constant Set Number1-auto numbered Thru

Nodes-Pick 3,4 (Element 3 is created)- OK

Step 6: Apply load conditionsAnsys Main Menu-Preprocessor-Loads-Define Loads-Apply-Thermal-Select Temperature- On

Nodes- Pick Node-1-Apply-select-TEMP- value 200-Apply

Pick Node -4-Apply-Select- TEMP-Value-600-OK

II. PROCESSING STAGEStep-7 Processing Stage or solutionStage

Ansys Main MenuSolution - Solve Current LS-OK

III. POST- PROCESSING STAGEStep 8: Plotting Animatingand listing resultsAnsys Main Menu- General Post Processor

Plot Results-Contour Plots-Nodal Solution DOF Solution temp OK (Temp distribution plot)

Plotctrls-Animate-Deformed Results-DOF Solution-Temperature-OK (for animation)

List Results-Nodal Solution-DOF Solution-Temp-OK(Temp All Nodes displayed)

RESULTS NODE NO: TEMP

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Problem 2: (2D Conduction and Convection): Determine temperature distribution through the

wall thickness of a tall chimney whose cross section is shown below. Assume that the inside gas

temperature is Tg =31 1 K. The inside convection coefficient is hi. The surrounding temperature is

Ta= 255 K and the outside coefficient is ho.

Select Element Type-Thermal Solid Element-PLANE 55

Given: K = 1.7307 W/mK, hi = 68.14 W/m2K and ho = 17.04 W/m2K.

Note: Geometric Properties-For Solving the problem only 1/8th

of the model is considered. (See 3-

D View) a = 4m and b = lm

Y

a 10 11

X

7 8 9

a

a/2 4 5 6

(a/2)-b

1 2 3

a/2

h0 Ta

hi T

Tall Chimney

FEM Model

2

3 4

56

1

b

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I. PRE-PROCESSING STAGEStep I: Setting the Preferences for GUI filtering

Ansys Main Menu -Preferences.

Select - ThermalOK

Step 2 : Defining Element Type

Ansys Main MenuPre processor

Element Type - Add /Edit /Delete - Addsolid Quad 4node 55-OK-close

Step 3 : Defining Real Constants

No Real Constants

Step4 : Define Material Properties

Ansys Main MenuPreprocessor

Material Properties - Material Models - Material Number 1- Thermal Conductivity

Isotropic-Conductivity For Material Number 1- Kxx 1.7307-OK close

Step 5: Create the Geometry of the Model

AnsysMain Menu - Preprocessor

Modeling-create-nodes-in active CS-X,Y,Z, location is CS

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Create-Elements-Auto Numbered-Thru Nodes-1, 2, 5 & 4 (Element 1 is created) - Apply

Pick 2,3,6 &5 (Element 2 is created)- Apply

Pick 4, 5, 8 & 7 (Element 3 is created)- Apply

Pick 5, 6, 9 & 8 (Element 4 is created)- Apply

Pick 7, 8, 10 & 10 (Element 5 is created)- Apply

Pick 8, 9, 11 & 10 (Element 6 is created)- Apply

Pick 10, 11, 12 & 12 (Element 7 is Created)-0K

Step 6: Apply Load Conditions

Ansys Main Menu-Preprocessor - Loads- Define Loads-Apply-Thermal- ConvectionOn NodesPick

Inner Surface by Box optionApplyFilm Coefficient (Inner) - 68.14-Bulk Temperature (At Inner surface)-

311-OK

ConvectionOn NodesPick Outer Surface by Box optionApplyFilm Coefficient (Outer) 17.04 - Bulk

Temperature (At outer surface)-255-OK

II. PROCESSING STAGEStep-7: Processing Stage or Solution Stage

Ansys Main Menu - Solution - Solve Current LS-OK

III. POST-PROCESSING STAGEStep 8: Plotting Animatingand Listing Results

AnsysMain Menu- General Post Processor

Plot Results-Contour Plots-Nodal Solution-DOF solution-Temp OK (Temp distribution plot)

Node no: x y

1 1 0

2 1.5 0

3 2 0

4 1 .5

5 1.5 .5

6 2 .5

Node no: x y

7 1 1

8 1.5 1

9 2 1

10 1.5 1.5

11 2 1 .5

12 2 2

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Pltctrls-animate - Deformed results- DOF Solution-Temperature-OK (For Animation)

List results- Nodal Solution-DOF Solution-Temp-OK (Temp All Nodes displayed)

RESULTS NODE NO: TEMP

Problem 3: For the body shown in the figure, determine temperature distribution. The body is insulated along

the top and bottom edges. Kxx = Kyy =1.7307 W/mC No internal heat generation is present.

11 12 13 14 15

2.5

400 C 6 7 8 9 10

- 20C 2.5

1 2 3 4 5

2m 2m 2m 2m

I. PRE-PROCESSING STAGEStep 1: Setting the Preferences for GUI filtering

Ansys Main Menu Preferences,

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Select - Thermal - OK

Step 2 : Defining Element Type

Ansys Main Menu Pre processor

Element Type - Add /Edit /Delete - Add Solid Quad-4node55-OK-Close

Step 3 ; Defining Real Constants

No Real Constants

Step 4:Define Material Properties

Ansys Main Menu - Preprocessor

MaterialProperties- Material Models - Material Model Number1-Thermal Conductivity-Isotropic-

Conductivity For Material No:1-Kxx 1.7307-OK-Close

Step 5: Create the Geometry of the Model

Ansys Main Menu-Preprocessor

Modeling-Create-Nodes-In Active CS -X,Y,Z location is CS

No X Y No X Y No X Y1 0 0 6 0 2.5 11 0 5

2 2 0 7 2 2.5 12 2 5

3 4 0 8 4 2.5 13 4 5

4 6 0 9 6 2.5 14 6 5

5 8 0 10 8 2.5 15 8 5

Create-Elements-Auto NumberedThru Nodes - Pick 1, 2, 7 & 6 (Element 1 iscreated ) - Apply

Pick 2,3,8 & 7 (Element 2 is Created)- Apply

Pick 3,4,9 & 8 (Element 3 is Created)- Apply

Pick 4,5,10 & 9 (Element 4 is Created)- Apply

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Pick 6 7, 12 & 11 (Element 5 is Created)- Apply

Pick 7,8,13 & 12(Element 6 is Created)- Apply

Pick 8,9,14 & 13 (Element 7 is Created)- Apply

Pick 9,10,15 & 14 (Element 8 is Created)- Apply

Step 6: Apply Load Conditions

Ansys MainMenu-Preprocessor - Loads- Define Loads-Apply-Thermal- Select Temperature On

Nodes-Pick inner surface by box option Apply-Select-TEMP-Value-40-Apply Pickoutersurface

by box option -Apply-Select- TEMP -Value-(-200c)-OK

II. PROCESSING STAGEStep-7: Processing Stage or Solution StageAnsys Main Menu - SolutionSolve Current LS-OK

III. POST-PROCESSING STAGEStep 8: Plotting Animating and Listing Results

Ansys Main Menu- General Post Processor

Plot Results-Contour Plots-Nodal Solution-DOF solutionTemp - OK ( Temp distribution Plot)

PIotctrls-Animate-Deformed results-DOF

solution

Temperature

OK ( For Animation)

List Results-Nodal Solution-DOF Solution-temp- OK(temp at All Nodes displayed)

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RESULTS

Node No Temperature

1

2

34

5

6

7

8

9

10

11

12

13

14

15