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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