Abstract:
This talk will first provide a quick overview of the research work that is currently being performed at Thermal Hydraulics Laboratory, Nuclear Engineering Program at The Ohio State University.  The work is in two major areas: gas-liquid two-phase flows for light water reactors and thermal hydraulics related to high-temperature reactors, including both gas cooled and molten salt cooled. The rest of the talk will then focus on the development of high-temperature compact heat exchangers for the gas-cooled reactors. Two printed circuit heat exchangers (PCHEs) were fabricated out of alloy 617 plates and are being tested in a High-Temperature Helium test Facility (HTHF) at Ohio State. The HTHF was designed and constructed for testing the thermal performance of these heat exchangers at temperatures and pressures up to 800 oC and 3 MPa, respectively. To date, tests have been performed at temperatures up to 700 oC. From the experiments, the thermal performance of the heat exchangers will be analyzed and discussed.  In addition, convective heat transfer coefficient and frictional factor for semi-circular flow channels in laminar and laminar-to-turbulent transitions flows will be derived from the experiments and compared with empirical models available in the literature.  Lessons learned from this study in carrying out high-temperature helium experiments will also be shared.

Brief bio:
Xiaodong Sun is currently an assistant professor of Nuclear and Mechanical Engineering at The Ohio State University and will be promoted to associate professor on Oct. 1, 2011. Dr. Sun received his B.S. in Thermal Engineering and M.S. in Nuclear Engineering from Shanghai Jiao Tong University, China, and M.S. in Mechanical Engineering and Ph.D. in Nuclear Engineering from Purdue University in 2001. From 2002 to August 2004, Dr. Sun was a postdoctoral research associate in the School of Nuclear Engineering at Purdue University. Dr. Sun’s research interest areas include reactor thermal hydraulics and safety; two-phase flow experimentation, modeling, and numerical simulation; and high-temperature reactors. He has co-authored 36 journal articles and over 70 conference papers. Dr. Sun currently serves as vice chair of the American Nuclear Society (ANS) Thermal Hydraulics Division, president of the ANS Alpha Nu Sigma National Honor Society, and vice chair of the ANS Book Publishing Committee. He was one of the two assistant Technical Program Chairs (TPCs) for the ANS 2011 Annual Meeting and is slated to be the TPC for the ANS 2012 Winter Meeting. Dr. Sun recently received the 2011 Lumley Engineering Research Award from the OSU College of Engineering.