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Dr. Frank Pyrtle, III, Assistant Professor
E-mail: pyrtle@eng.usf.edu Website: http://www.eng.usf.edu/~pyrtle Telephone: 813-974-9015 Location: ENC 2508
Education Ph.D. Mechanical Engineering, Georgia Institute of Technology M.S. Mechanical Engineering, Texas A&M University B.S. Mechanical Engineering, Texas A&M University |
Research Interests Two-Phase Heat Transfer, Droplet and Spray Cooling, Micro/Nano Scale Heat Transfer Microelectronic Device Thermal Management |
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Nanostructure Boiling Enhancement and Spray Cooling
Phase-change heat transfer is characterized by high heat transfer coefficients of 2,500 to 100,000 W/(m^2*K). Thus, for low temperature differences between the heated surface and the cooling liquid, high heat fluxes are possible. Means for high heat flux cooling are necessary for continued advancements in microelectronics development, nuclear power generation, metallurgical processing, and other applications where thermal management is important.
Two high heat flux cooling methods we
are investigating involve boiling and spray cooling. Investigation
of these methods of heat dissipation is important because they are
often integral
Spray cooling can also be used to produce high heat fluxes at low superheat temperatures. Spray cooling of an inverted, heated surface is being investigated to determine heat fluxes for various spray and surface conditions. Unlike conventional spray cooling experiments in which droplets are directed downward onto a heated surface, in this investigation, the spray is directed upwards to cool a heated surface that faces downward. Thus, in this configuration, vapor that is created by droplet evaporation does not freely move away from the heated surface. Objectives of this investigation are identification of the underlying physical mechanisms affecting heat transfer, determination of heat transfer regimes, and development of correlations to estimate heat fluxes.
Sponsor: Department Principal Investigator: Frank Pyrtle, III Collaborators: N/A |
processes to many thermal management systems. The
boiling investigation focuses on the effects of nanostructured
surface features on nucleate boiling. During nucleate boiling,
bubbles initiate in cavities on the heater surface (nucleation
sites). By changing the nucleation site geometry and distribution,
the heat flux can be increased or decreased. Using nanostructured
layers, deposited on the heater surface, nucleation site
characteristics can be modified to maximize heat flux in the
nucleate boiling regime.