Mechanical Eng. / Korea Advanced Institute of Science and Technology / 2010
Primary collaborative faculty member/s:
Nano and microscale surface treatment technique for boiling heat transfer enhancement. Topology and surface property effect of nano and microscale structures on heat transfer performance.
Impact Statement & Explanation of Research:
My research topic is surface treatment for boiling heat transfer enhancement. Surface treatment is well known for its efficacy in heat transfer enhancement, and many variants of treated surfaces have been developed. Most fall in the categories of porous-layer coatings, attached nucleation promoters, and mechanically roughened surfaces. However, it has also been reported that treated surfaces, especially coatings of any kind, can decrease thermal performance by increasing thermal resistance, especially for the case of flow boiling heat transfer. These contradictory results come from a lack of intensive studies focusing on quantification and visualization of the boiling heat transfer phenomena on treated surfaces. The present work will be devoted to investigating the effects of topology and physical properties (such as surface wettability) of treated surfaces on boiling heat transfer in FC-72 and DI water. Detailed boiling heat transfer characteristics, including bubble departure size, frequency, and bubble residence time, will be measured by using synchronized cameras and a test piece comprised of glass substrate and metal porous layers. In addition, we focus on the fact that treated surfaces in previous studies had fixed morphologies such as with sintered porous layers. To provide fundamental insights, the effects of free particles on boiling heat transfer will be studied in first-of-their-kind experiments, and the results will be compared to the case of conventionally treated surfaces. Based on the experimental results, design guidelines for treating surfaces for boiling heat transfer improvement will be proposed.