Download - A study investigating the thawing of the most important meal of the day by Russell Dibb 3/31/2010
![Page 1: A study investigating the thawing of the most important meal of the day by Russell Dibb 3/31/2010](https://reader035.vdocuments.mx/reader035/viewer/2022062317/5a4d1b0e7f8b9ab05998cdc8/html5/thumbnails/1.jpg)
A study investigating the thawing of the most important meal of the day
by Russell Dibb3/31/2010
![Page 2: A study investigating the thawing of the most important meal of the day by Russell Dibb 3/31/2010](https://reader035.vdocuments.mx/reader035/viewer/2022062317/5a4d1b0e7f8b9ab05998cdc8/html5/thumbnails/2.jpg)
How long does it take to thaw foods that come right out of the freezer?
![Page 3: A study investigating the thawing of the most important meal of the day by Russell Dibb 3/31/2010](https://reader035.vdocuments.mx/reader035/viewer/2022062317/5a4d1b0e7f8b9ab05998cdc8/html5/thumbnails/3.jpg)
Freeze food items (~267 K)
Allow for free convection
Conduct experiment at room temperature (~295 K)
Record and analyze data
![Page 4: A study investigating the thawing of the most important meal of the day by Russell Dibb 3/31/2010](https://reader035.vdocuments.mx/reader035/viewer/2022062317/5a4d1b0e7f8b9ab05998cdc8/html5/thumbnails/4.jpg)
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
Temperature
Lumped Capacitanc
e
Transient Conduction
Actual
270 K 7.0 minutes
11.1 minutes
25.5 minutes
![Page 5: A study investigating the thawing of the most important meal of the day by Russell Dibb 3/31/2010](https://reader035.vdocuments.mx/reader035/viewer/2022062317/5a4d1b0e7f8b9ab05998cdc8/html5/thumbnails/5.jpg)
Temperature
Location Transient Conduction
Actual
270 K Center 17.7 minutes
22.5 minutes
275 K Surface 3.0 minutes
2.6 minutes
280 K Surface 13.4 minutes
7.5 minutes
Sphere in free convection h_bar = 5.8 W/m^2
K Bi = 0.22 Surface
measurements most realistic
![Page 6: A study investigating the thawing of the most important meal of the day by Russell Dibb 3/31/2010](https://reader035.vdocuments.mx/reader035/viewer/2022062317/5a4d1b0e7f8b9ab05998cdc8/html5/thumbnails/6.jpg)
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
Temperature
Lumped Capacitanc
e
Actual
280 K 4.6 minutes
7.5 minutes
285 K 7.4 minutes
12.7 minutes
![Page 7: A study investigating the thawing of the most important meal of the day by Russell Dibb 3/31/2010](https://reader035.vdocuments.mx/reader035/viewer/2022062317/5a4d1b0e7f8b9ab05998cdc8/html5/thumbnails/7.jpg)
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)