Page 207 - Using ANSYS for Finite Element Analysis Dynamic, Probabilistic, Design and Heat Transfer Analysis

194 • using ansys for finite eLement anaLysis

Nominal
Material properties value Distribution
Thermal Conductivity 398 W/m.K At Average Temperature
Coefficient T = (T + T )/2 = 62.5°C ~ 355k
b
∞
Convection Heat 10 W/m .K
2
Transfer Coefficient
Nominal
Loading value Location
Temperature Thermal 100°C At the base of the fin.
Load
Convection Thermal 10 W/m .K At the cylindrical edge and the
2
Load flat face at the tip of the fin.

5.3.1 APPRoACh AnD ASSUMPTionS

• Since the problem is axisymmetric only a small sector of elements
is needed. A rectangular strip is used for approximating the cylin-
drical fin.
• The analysis is carried out for steady-state conditions.
• Material properties are considered to be constant.
• One-dimensional conduction along the rod.
• Negligible radiation exchange with surroundings.
• Uniform heat transfer coefficient.

5.3.2 SoLUTionS/ReSULTS

Results FEA Book (Incropera)
Units Watts (W) Watts (W)
Total Heat Loss 29.09103 29.4

5.3.3 inPUT FiLe USing Log FiLe

You can perform the example optimization analysis of a cylindrical fin
using the ANSYS commands shown as follows. Items prefaced with an
exclamation point (!) are comments.
The analysis happens in essentially two passes. In the first pass, you
create the analysis file. In the second pass, you create the optimization
input. If you prefer, you can perform the second pass of the example anal-
ysis using the GUI method rather than ANSYS commands.