Woodruff School of Mechanical Engineering
Mechanical Engineering Seminar
Wettability-based control & enhancement of phase change heat transfer: New concepts and applications
Prof. Vaibhav Bahadur
The University of Texas at Austin
Monday, April 9, 2018 at 11:00:00 AM
MRDC Building, Room 4211
Dr. Satish Kumar
Phase change phenomena (boiling, condensation, freezing) affect the performance and efficiency of numerous energy systems. Liquid-solid wettability is a powerful tool to influence phase change heat transfer. This talk highlights recent advancements from the author’s group in the areas of boiling, condensation, freezing, and connects them to specific applications. The first topic is electrowettabilty-induced elimination of film boiling (Leidenfrost state), which can fundamentally change the shape of the boiling curve and make critical heat flux considerations irrelevant. Applications of this concept exist in materials processing and steam generation. As an illustration, electrically-tunable boiling can enable control of mechanical properties during quenching of metals. Electric fields can also enable novel heat pipe architectures to move high (kiloWatt) heat loads over long distances. The microfluidics underlying such an electrowetting heat pipe was recently characterized on the International Space Station. The second topic is dropwise condensation, which enables higher heat transfer due to rapid condensate removal on hydrophobic surfaces. The benefits of rapid condensate removal can also be realized by using electrowetting to promote rapid coalescence of condensed microdroplets, which will enable rapid growth and shedding of droplets. Dropwise condensation has several applications; this talk will highlight the benefits of condensation-based atmospheric water harvesting, which can be powered by excess natural gas from landfills and oilfields. The third topic is the use of electric fields to promote freezing (electrofreezing), which has multiple applications related to natural gas hydrates and ice. Electrowettability can influence the freezing temperature of liquids and provides options for dynamic control of freezing and crystal growth. Overall, this talk will discuss recent advancements in phase change, and highlight benefits in the areas of power generation, waste energy utilization, oil-gas production and manufacturing.
Prof. Vaibhav Bahadur (VB) is an Assistant Professor of Mechanical Engineering at UT Austin. His research interests are in the areas of phase change heat transfer, surface science, microfluidics, and energy systems. Prof. Bahadur’s research is targeted at a fundamental understanding of microscale thermal-fluid-particle transport phenomena with applications in energy, water and environmental protection. Prof. Bahadur has a PhD in Mechanical Engineering from Purdue University and a Postdoc from Harvard University. Additionally, he has 4 years industry R&D experience in GE Global Research and Baker Hughes. Prof. Bahadur is the recipient of the NSF CAREER Award (2017), the SPE Petroleum Engineering Young Faculty Award (2015), the ACS Doctoral New Investigator Award (2014) and the Google Faculty Research Award (2018). He is the winner of the Society of Petroleum Engineer’s R&D Competition at SPE Annual Technical Conference and Exhibition (2014). Prof. Bahadur has more than 60 journal/conference articles (h-index of 19), 3 patents and 6 pending patent applications. His research has been featured on the cover of ASME’s Mechanical Engineering magazine and ACS Nano, and in R&D magazine.
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