1. Shaun Heldt and Tyler Merrell

2. Background  Most common type of cooling method  Keeps CPU at a safe operating temperature  Has fan to improve overall heat transfer of fins by introducing forced convection.

3. Materials  1Intel I7-26000K Processor heat sink  1Fluke 51 Thermometer with K- thermocouple  1Soldering Iron  1Hot Glue Gun

4. Experiment  Used glue gun and soldering iron to simulate a hot CPU  Measured temperature of the center of the heat sink and the fin tip while heating  Measured time to cool after heated  Compared with theoretical calculations to solve for Q out and the required air velocity for forced convection

5. Data

6. Natural Convection  Solve for Qout from natural convection of the heat sink to find if cooling due to natural convection is sufficient for cooling CPUs  Note: Q in from CPU equals 80W  Therefore, Q out must be greater than or equal to 80W for natural convection to be sufficient

7. Natural Convection Calculated Properties

8. Thermal Circuit

9. Compiled Calculations Q out = 6.77W Therefore, natural convection is not sufficient Thermal Circuit Method

10. Forced Convection  Used forced convection calculations to solve for required airspeed from fans to have a Q out = 80W  Using previous calculations, an h value of 143.138 W/m 2 would be required to sufficiently cool the CPU  Using Hilpert’s equation for cross flow of a square geometry and thermophysical properties we found that the required airspeed velocity is 2.913 m/s

11. Conclusion  Approximations were made to form the model used in calculating the presented values, however, we believe that this model was a reasonable approximation of the system.  We found that forced convection through a heat sink is necessary in CPU cooling