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 –h fg = 2257 kJ/kg –v l = 1.044*10 -3 m 3 /kg –v g = m 3 /kg –c p = 4217 J/kg*K –  = N*m –k m = W/m*K Hot dogs are cylinders

Experiment Initial Temperature = 15 o C Final Temperature = 76 o C Water Temperature at Boiling = 92 o C Length of Hot Dog = m Diameter of Hot Dog = m Mass of Hot Dog = kg Cooking Time = 249 sec

Lumped Capacitance Method q” = W/m^2Eq h = W/m^2*K Bi = 126.8Eq Bi >> 0.1invalid t = 2.55 sec << 249 sec

Transient Conduction Bi = Table 5.1  = C1 = t = 676 sec

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