To tackle the 21^st century critical challenge of supplying more energy in a sustainable manner, it is important to design and manufacture advanced materials for phase change heat transfer applications, especially thermal energy conversion. Efforts in this area have been catalyzed by the emergence of novel mini-, micro- and nano-scale methods for surface manufacturing, which help control the various length scales and better manage the fluid phases.

With such surface control comes the ability to maximize energy transport and optimize thermodynamic efficiency for producing and converting energy. Consequently, many industries and research teams have worked tirelessly towards developing advanced engineered surfaces with better performance in boiling, condensation and icing/frosting. In this talk, after showing that three key phase change processes share several important features, we review recent developments in surface texturing and chemical modification of technologically-relevant, thermally-conductive materials. We also review the history of engineered surfaces for enhancing phase change heat transfer. Five opportunities are identified to engineer better surfaces for phase change heat transfer: design, physical process understanding, suitability for commercial fluids, reliability and manufacturing. Specifically, we will emphasize the history and recent developments of biphilic surfaces, which juxtapose hydrophilic and hydrophobic regions. Biphilic surfaces were first manufactured in the 1960’s by spraying Teflon drops onto a smooth steel surface, resulting in enhanced heat transfer coefficients during boiling. Our recent work has revisited the manufacturing of biphilic surfaces using state-of-the art micro- and nanofabrication processes [1]. Using biphilic surfaces, we measured significant enhancement during pool boiling of both the heat transfer coefficient and the critical heat flux. This enhanced performance can be explained by the inherent ability of biphilic surfaces to control and enhance multiphase flow.

The talk aims at providing researchers in the two communities of material science and heat transfer with a synthetic perspective on the explosively growing area of advanced engineered surfaces for phase change heat transfer, which is important to sustain the future of mankind.

 

报告人简介：

Daniel Attinger’s research area is in fluid dynamics and heat transfer at small scales, with applications in forensics, bioengineering, energy technologies. After a 2001 PhD at ETH Zurich and faculty positions at Stony Brook and Columbia University, Attinger is since 2011 tenured Associate Professor at Iowa State University. He has given seven keynote lectures at international heat transfer and microfluidic conferences, and more than 50 invited talks in America, Asia and Europe. He has produced about 80 journal and conference papers. Attinger is a member of the Nanoengineering Council of the American Society of Mechanical Engineers, where he chairs the Micro & Nano Technology Society-Wide Forum, and the 2014 International ASME Conference on Micro, Nano and Minichannels. Attinger is the co-inventor of four US and international patents. He is the recipient of the ETH Zurich medal for outstanding Ph.D. thesis (2001), an NSF CAREER award for young investigators (2005), the 2012 ASME ICNMM 2012 Outstanding Researcher Award. He leads one of the 7 teams of the 2013 Presidential Interdisciplinary Research Initiative at Iowa State University, and received the Award of Professor of the Year 2014 by the senior class of Mechanical Engineering. The first three PhD graduates of Attinger’s lab have obtained tenure-track faculty positions at research universities.