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Hot Dog!

Allison Lee

Victoria Lee

Experiment Set Up

• Compare the lumped capacitance method and transient conduction

• Time it takes to cook a hot dog compared to time predicted

Assumptions• Hot dogs have the same properties as chicken

meat and water– hfg = 2257 kJ/kg

– vl = 1.044*10-3 m3/kg

– vg = 1.679 m3/kg

– cp = 4217 J/kg*K

= 0.0589 N*m

– km = 0.489 W/m*K

• Hot dogs are cylinders

Experiment• Initial Temperature = 15oC

• Final Temperature = 76oC

• Water Temperature at Boiling = 92oC

• Length of Hot Dog = 0.133 m

• Diameter of Hot Dog = 0.019 m

• Mass of Hot Dog = 0.049 kg

• Cooking Time = 249 sec

Lumped Capacitance Method

• q” = 1106857.1 W/m^2 Eq. 10.6

• h = 13021.8 W/m^2*K

• Bi = 126.8 Eq. 5.10

• Bi >> 0.1 invalid

• t = 2.55 sec << 249 sec

Transient Conduction

• Bi = 253.65 Table 5.1 = 2.4050

• C1 = 1.6018

• t = 676 sec

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Conclusions• Using the lumped capacitance method

when it is invalid will result in a extremely skewed answer

• The transient conduction yields a more accurate answer in this case

• Errors in predictions are due in part to differences in assumed and actual property values