Thermal Analysis
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Transcript Thermal Analysis
Thermal Elements
Jake Blanchard
Spring 2008
Thermal Elements
These elements calculate temperatures in
solids
There are 1-D, 2-D, and 3-D elements
All have just 1 DOF per node
Properties are thermal conductivity (k) for
steady state analysis and density () and
heat capacity (cp) for transient analyses
Boundary conditions can be temperatures,
heat fluxes, or radiation
Volumetric heating is also possible
Thermal Elements in ANSYS
LINK 31 – radiation link
LINK 32 – 2-D conduction bar
LINK 33 – 3-D conduction bar
LINK 34 – convection link
PLANE 35 – 6 node triangle
PLANE 55 – 4 node quad
PLANE 75 – 4 node axisymmetric-harmonic
element
PLANE 77 – 8 node quad
PLANE 78 – 8 node axisymmetric-harmonic
element
More Thermal Elements
SOLID 70 – 8 node solid
SOLID 87 – 10 node tetrahedral element
SOLID 90 – 20 node hexahedral element
SHELL 57 – 4 node
SHELL 131 – 4 node layered element
SHELL 132 – 8 node layered element
Real Constants
Area, heat transfer coeff., and emissivity
for links
None for planar and solid elements
Thickness for shell element (not
layered)
Use “Sections” for layered elements
In-Class Problems
T=0 C
k1=1 W/m-K
k2=20 W/m-K
1
2
T=100 C
1 cm
10 cm
In-Class Problems
T=0 C
k1=1 W/m-K
k2=20 W/m-K
q=104 W/m2
1
2
1 cm
10
cm
In-Class Problems h=1000 W/m2-K
Tb=50 C
k1=1 W/m-K
k2=20 W/m-K
q=104 W/m2
1
2
1 cm
10
cm
In-Class Problems T=50 C
k1=1 W/m-K
k2=20 W/m-K
Channels are 3 cm
in diameter
2
2 cm
1
15
cm
1 cm
q=104 W/m2
10
cm
In-Class Problems h=1000 W/m2-K
Tb=50 C
k1=1 W/m-K
k2=20 W/m-K
Channels are 3
cm in diameter
2
2 cm
1
15
cm
1 cm
q=104 W/m2
10
cm