Spring 2003 - METBD 452 Transient Problem

Prof. Dave Johnson, dhj1@psu.edu, Penn State - Erie, The Behrend College

Reference:  J.P. Holman, "Heat Transfer", 7th ed., 1990, McGraw-Hill, p. 181-183.

A 0.01 by 0.02 m. ceramic strip is initially at a uniform temperature of 300^oC.

The left and right sides are maintained at a constant temperature of 300^oC.

The bottom surface is perfectly insulated.  Assume unit depth for this part.

Radiation is not to be considered in this problem.

Model this cooling process for 12 seconds.

MAKE SURE that the air temperature (T_BULK) is at 50^oC for the ENTIRE simulation.

Find the temperature at the three points (A, B, and C) labeled on the figure as the part cools.

Compute the average rate of heat loss (in Watts) over the 12 second process.
In the time history postprocessor, you could simply average the "instantaneous" value of heat flow rate at each solution - OR - more accurately, you could integrate the heat loss rate over the time interval and finally divide by the time period to obtain the average heat loss rate.

Turn in:

• a model geometry plot showing all loads and boundary conditions
• a final results contour plot of the temperature distribution in the part after 12 seconds
• time history plots of:
  • the total heat lost by convection,
  • the temperature at the three points (A, B, and C) labeled on the figure, and
  • the solution's integration time step size during the analysis
• a table comparing the FEA solution to the reference text's results (temperature and heat loss data)** 
  HINT: use List Variables in the Time History Postprocessor to get the "table" of ANSYS results for T_A, T_B, T_C and Q_OUT)
• Include your hand calculations for the initial integration time step size.
• 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.

**  from the textbook:  The average rate of heat loss over 12 sec. = 464.4 W