70 likes | 149 Vues
This study by Russell Dibb on 3/31/2010 delves into the thawing process of frozen foods for breakfast. Conducting experiments at room temperature, findings show varied thawing times for items like bananas, bread, cookies, and more. The research reveals insights into convection, heat transfer rates, and practical considerations for thawing your favorite morning foods efficiently.
E N D
A study investigating the thawing of the most important meal of the day by Russell Dibb 3/31/2010 I Eat Heat Transfer for Breakfast
How long does it take to thaw foods that come right out of the freezer? What’s for breakfast?
The process Freeze food items (~267 K) Allow for free convection Conduct experiment at room temperature (~295 K) Record and analyze data
results - banana • 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
results - bread • Sphere in free convection • h_bar = 5.8 W/m^2 K • Bi = 0.22 • Surface measurements most realistic
results - cookie • 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
Assumptions and conclusions 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)