Verification of Heat Transfer Predictions with Ice-cream By:Matt Munyan and Clifton Mortensen

Ice Cream Mixer Overview  The liquid ice cream is placed inside of the metal container with the mixer.  The metal cylinder is then placed inside the wood container.  Ice and salt are then packed in between the metal and wood.  Then the crank is put on and turned.  New ice and salt are continually put in to replace the exiting salt water mixture.

Problem Overview  We compared the time it takes for the ice cream to reach its equilibrium temperature against our theoretical approximations.  We modeled the ice cream, the ice and its container as a cylinder using the thermal resistance method.

Assumptions  Neglect Kinetic Energy effects (heat from viscous friction and convection)  Uniform ice cream temperature  Constant specific heat  Neglect effects from measuring temperature  Ice/salt cylinder at constant temperature (neglect melted ice)  q”=0 through the top and bottom surfaces  Approximate metal container as a thin wall

Results

Conclusions and Recommendations  The model fits the data accurately until the freezing temperature of the ice cream where the temperature of the ice cream remains constant during the phase change.  Further study and testing is recommended with less intrusive measurement techniques and more control over environment.  A more exact method of finding the percentage of ice and salt is required.

Interior of Ice Cream Mixer Overhead Shot of Mixer

Derivation of Equations