1. Microchannel Heat Sink Experiment: Testing Convective Coefficients Instructor: Dr. Ralph Budwig Fall 2006 Nicholas Tebbe Victor Ponce James Dorrell December 7, 2006

2. Background and Motivation Playstation 3 Nvidia GeForce 7950

3. Objectives Determine the convective coefficient 80% certainty Reynolds numbers between 500-1500 Lee, Poh-Seng; Garimella, Suresh V.; Liu, Dong “Investigation of heat transfer in rectangular microchannels.” International Journal of Heat and Mass Transfer 48, 2005, 1688-1704.

4. Prototype: Microchannel

5. Photos

7. Prototype: Manifold

8. Setup NumberComponent 1Water Reservoir 3Pump 5Manifold 6Microchannel Substrate 7Nichrome Heater 9Thermocouple 10Graduated Cylinder To and Ti Tc ΔVΔV ΔtΔt

9. Energy Balance Newton’s Law of Cooling Data Reduction

10. RSS Analysis Max Uncertainty Re: 8.8% h: 13.54% Experiment Design

11. Minimizing Uncertainty Percent Contribution Reynold’s Number –Viscosity of Water: 70% –Velocity calculation: 25% Convection Coefficient –Water Outlet Temperature: 60% –Copper Temperature: 10%

12. Results

13. Comparison

14. Conclusions Max Uncertainty = 13.54% Temperature contributed 60% of error Rough channels cause turbulence Dittus-Boelter Correlation recommended

15. Questions ?