Hungry??? Grab a chimichanga!

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Hungry???Grab a chimichanga!

• Steve McFarland
• Aaron Boyd

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How Hot is my Chimichanga?

• As I move on to the 5th hour of heat transfer
  homework, my hunger suddenly takes over and I
  cannot concentrate anymore. I need a chimichanga!
  I buy one from the vending machine and pop it in
  the oven. As I watch it cook, my engineering mind
  takes over, and I cant help but wonder, how hot
  is the chimichanga at a given time?

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SETUP

• Using the Lumped Capacitance Method, assuming the
  chimichanga to behave like a cylindar, and using
  thermophysical properties of water, we determined
  the temperature of a chimichanga at different
  times, cooking at 350 degrees F.
• T(t) T 8 (To - T 8)e(-h As t)/(? cp V)
• Bi (h Lc)/k

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How hot is it???

• For full results, see appendix

5
Conclusions

• Temperature of Chimichanga goes up quickly and
  levels off around 350 degrees after approximately
  1 hour...but you probably dont want to eat it!
• The biot number is too high to validly use the
  lumped capacitance method, but it gives a good
  estimate of the temperature at any given time.

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Appendix

• See attached file