Spring 1998, METBD452 - FEA Heat Transfer Applications
Prof. Dave Johnson, dhj1@psu.edu, Penn State - Erie, The Behrend
College
Project Assignment 3
Concepts:
- Modeling: Sweeping an ALL Brick mesh from a 2D cross-section
- Conduction, Convection, Heat Flux Loading
- Steady-state Thermal Analysis
- Thermal-Stress (Structural) Static Analysis
The figure above shows a plastic headlight housing model. The
structure has been simplified to one-half of a cylindrical container. The material
is a glass-filled polycarbonate.
The material properties are:
| Thermal Conductivity |
Specific Heat |
Density |
| (BTU/hr-in-oF) |
(BTU/lbm-oF) |
(lbm/in3) |
| 0.0025 |
0.15 |
0.052 |
| Young's Modulus |
Poisson's Ratio |
Coefficient of Thermal Expansion |
| (psi) |
- |
(in/in/oF) |
Reference Temp. |
| 1.2x10 6 |
0.2 |
1.3x10 -6 |
70oF |
Perform a steady-state heat transfer analysis of this structure
which experiences this thermal loading:
- Outside top (semicircular) face, free convection to air at 65 oF,
h = 0.0103 BTU/hr-in2-oF
- Outside bottom (semicircular) face, free convection to air at 65
oF, h = 0.0046 BTU/hr-in2-oF
- Outside vertical faces and outside edges around the rectangular
opening in the front, free convection to air at 65 oF, h = 0.0141 BTU/hr-in2-oF
- Inside top (semicircular) face, constant heat flux of 4.0 BTU/hr-in2
- Inside bottom (semicircular) face, constant heat flux of 2.0
BTU/hr-in2
- Inside vertical walls, constant heat flux of 3.0 BTU/hr-in2
- You may ignore radiation for the heat transfer analysis.
Perform a static structural solution of this part under the
temperature profile determined in the thermal solution. (The only load on the
structure will be the thermal strain caused by the heat input). The structural
constraints on this part are shown on the figure and include four points where zero
displacement is imposed:
- UX, UZ at the upper left corner
- UX, UY, UZ at the lower left corner
- UY, UZ at the lower right corner
- UZ at the upper right corner
where: X is the direction of the 4" long
edge, Y is the 1.5" thickness, and Z is normal to the rectangular opening at the
front of the housing.
Report, should include:
- Plots showing the model geometry and boundary conditions (thermal and
structural)
- Thermal results plot of the temperatures on the model.
- Comment on the amount of heat dissipated through the model's walls:
what rating of bulb (in W) could produce that amount of heat ?
- Structural results plots showing the deflection and stress produced
by the thermal loads.
- Include the annotated log file, showing the model generation and
solution.
Reminder: All project reports will be typed, and include:
- a cover page with course name, project name, team
names, and date
- a brief objective statement (2-3 sentences, maximum)
- a summary of procedures (bulleted items: assumptions,
data, analysis steps)
- a conclusion statement (what was learned, perhaps an
evaluation of the design)
- a copy of the project statement (this web page) may be
attached.