Thesis
Thermal and flow impact of cylindrical grooves in channel flow
Washington State University
Master of Science (MS), Washington State University
2009
Handle:
https://hdl.handle.net/2376/101837
Abstract
Due to rapid advancements in device technology, the thermal dissipation from power electronics is approaching 80 W/cm2 , which is the capability of traditional energy removal technology for small packaging applications. To dissipate these high heat fluxes, air-cooled heat sinks are being replaced with liquid-based micro-channels. Though these micro-channels have the capability of transferring more energy than traditional heat sinks, they can incur higher pressure penalties that make them impractical in small electronic packaging applications. One feasible alternative is to use slightly larger passages with surface enhancements fashioned on the sidewalls of the channel. This allows for lower pressure penalties while increasing the heat transfer 20-30% more than a comparable plane channel. A particularly intriguing enhancement is the cylindrical groove, which incurs a minor pressure penalty while leading to higher heat transfer coefficients through the mechanisms of stirring, impingement, and redevelopment of the boundary layer. To examine this concept, computational fluid dynamics was used to simulate the thermal and flow performance for 108 cases, varying groove size and flow rate. Pressure, temperature, and shear stress profiles were nondimensionalized using pressure coefficient, Nusselt number, and skin friction coefficient, respectively. The average of each profile was compared to a baseline, flat channel case to estimate the performance of each groove. Transfer functions were then generated to describe the thermal and flow behavior for different groove sizes in milli-channels. An optimal case was chosen, manufactured, and experimentally tested using infrared thermography in an effort to validate the simulations. Both computational and experimental results indicated that the groove geometry and flow rates that led to turbulent separated flow showed the highest thermal benefit; though, the exact geometry differed. Further experimentation using particle image velocimetry was recommended to validate the results obtained through computational fluid dynamics.
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Details
- Title
- Thermal and flow impact of cylindrical grooves in channel flow
- Creators
- Thomas E. Conder
- Contributors
- Stephen A. Solovitz (Degree Supervisor)
- Awarding Institution
- Washington State University
- Academic Unit
- Mechanical and Materials Engineering, School of
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University; Pullman, Wash. :
- Identifiers
- 99900525278601842
- Language
- English
- Resource Type
- Thesis