Document Type
Presentation
Journal/Book Title/Conference
AIAA Region VI Student Conference
Publisher
American Institute of Aeronautics and Astronautics
Publication Date
3-25-2011
Faculty Mentor
Heng Ban
Abstract
The motivation of this nucleate boiling research is to understand the effects of surface geometry and heat flux as applied to a thin wire heater. This will further the understanding of the fundamental behaviors of boiling onset, steady state heat transfer, and bubble dynamics with respect to nucleate boiling with the goal of creating efficient thermal management systems for future space applications. Using three different thin platinum wire geometries and five different power levels, subcooled water was boiled over a period of approximately 30 seconds for 15 parabolic arcs to simulate microgravity. To represent the trends in bubbles behavior across hundreds of frames of video in a single graph, a new method, named relative bubble area analysis, is introduced and used to analyze the results of the experiment. It was determined that the efficiency of steady state heat transfer via nucleate boiling in microgravity is comparable to, and in some cases more efficient than, steady state heat transfer in terrestrial applications. The three-wire geometry reduced the heat flux necessary to initiate boiling. Bubble dynamics show a transition from isolated bubbles to jets of small bubbles as heat flux increases. This can be confirmed both visually and with relative bubble area analysis. The implications of this research are that sustained convective heat transfer with subcooled water is possible in microgravity. A three-wire surface geometry was shown to initiate boiling at lower heat fluxes, which would provide minimal super heating of the surface, which is a result of the lack of convection, before boiling heat transfer could begin.
Recommended Citation
Munro, T., & Fassman, A. (25 March, 2011). Surface Geometry and Heat Flux Effect on Thin Wire Nucleate Pool Boiling of Subcooled Water in Microgravity. Presented at the AIAA Region VI Student Conference, San Diego, CA: American Institute of Aeronautics and Astronautics.
Comments
Conference Program available at this link.
Faculty Advisor: Heng Ban, USU Dept. of Mechanical and Aerospace Engineering
Acknowledgments: USU Get Away Special (GAS) team of 2010; National Instruments; SpaceX; USU Space Dynamics Laboratory; American Aerospace Advisors; Rocky Mountain NASA Space Grant Consortium; USU Physics Department; USU Mechanical and Aerospace Engineering Department; USU College of Science; College of Engineering; USU Undergraduate Research Office; Gil Moore; Scott Thomas; Russ Laher; NASA Reduced Gravity Student Flight Opportunities Program; Justin Koeln; Robert Barnett; Dr. JR Dennison, USU Dept. of Physics; Dr. Jan Sojka, GAS team advisor, USU Dept. of Physics.