1. ME 340-1 Kyle Dallon, Natalie Gibb March 29, 2010

2. Objective: Test the accuracy of convection equations in real life application. Experiment: Predict time to cool down boiling water in 2 cases: 1. With cross flow 2. With natural convection

3. Forced Convection Method Treat pot of boiling water like a tube and use equations for forced convection around a cylinder. Use Hilpert equation, Nu D =.027*Re.805 *Pr 1/3 Use lumped capacitance to calculate time. Not accurate time estimate. Results Calculated Results Measured Results Time, Case 1 81 min13 min Time, Case 2 488 min30 min

4. Flat Plate in Parallel Flow Treat pot of boiling water like a flat plate in parallel flow. Use Nu D = 0.664*Re 1/2 *Pr 1/3 Use lumped capacitance to calculate time. Much more accurate estimation. Results Calculated Results Measured Results t (min) Case 1 9.7 min13 min t (min) Case 2 36.8 min30 min

5. Conclusions/Recommendations Case 1: Forced Convection Method was not valid for our experiment. A pot of boiling water is better modeled as a flat plate in parallel flow. Case 2: Free Convection modeled as a horizontal plate was reasonably accurate.