1. A study investigating the thawing of the most important meal of the day by Russell Dibb 3/31/2010

2.  How long does it take to thaw foods that come right out of the freezer?

3.  Freeze food items (~267 K)  Allow for free convection  Conduct experiment at room temperature (~295 K)  Record and analyze data

4.  Cylinder in free convection, h_bar = 6.6 W/m^2 K  Bi = 0.11  Longer than expected  Errors in measurement  Included peel  Approximate k TemperatureLumped Capacitance Transient Conduction Actual 270 K7.0 minutes11.1 minutes25.5 minutes

5. TemperatureLocationTransient Conduction Actual 270 KCenter17.7 minutes22.5 minutes 275 KSurface3.0 minutes2.6 minutes 280 KSurface13.4 minutes7.5 minutes  Sphere in free convection  h_bar = 5.8 W/m^2 K  Bi = 0.22  Surface measurements most realistic

6.  Plate in two-sided free convection  h_bar = 6.7 W/m^2 K  Bi = 0.04  Lumped capacitance  Approximated k from weighted average of ingredients TemperatureLumped Capacitance Actual 280 K4.6 minutes7.5 minutes 285 K7.4 minutes12.7 minutes

7.  Air conditions relatively tranquil  Radiation neglected for ease of calculation, small temperature difference  Models underestimate actual thawing time  Exception: bread surface  Heat is very unevenly distributed in bread  Do not freeze a banana if you intend to eat it (they become squishy and less appetizing)