应威尼斯欢乐娱人城官网3328陈文礼和李惠教授邀请，韩国翰林院院士、釜山国山大学（Pusan National University）机械工程系 Kyung Chun Kim教授将于近日访问我校并做学术报告，欢迎感兴趣的师生参加。
报告题目：Complex fluid-flows through stochastic porous media
报告时间：2019年1月25日 上午 9:00-10:30
报告地点：土木学院303室
摘要：In the past decades, heat transfer and flow behavior in porous medium has attracted lots of researchers. Random nature of stochastic foam provides favorable geometrical properties for thermal applications such as large specific surface area and high porosity. However, notwithstanding intensive investigations for the last two decades, hydrodynamic characteristics of stochastic foam are still poorly understood. Current 3-D printing technology supports printing of transparent complex structures. This study investigates hydrodynamic characteristics of a stochastic foam. Using micro-tomography and stereo-lithography, a transparent stochastic foam was printed. Quantitative flow visualization was performed using refractive index matching technique and time-resolved particle image velocimetry. Mixing and turbulence characteristics were discussed. Mechanical mixing and high turbulence in the stochastic foam is beneficial for thermal applications, but large wake area behind the struts cause high pressure drop. On the basis of the results, a new concept of turbulence due to complex geometry can be named as “structure generated turbulence (SGT)”. Geometrical properties of high-porosity open-cell metallic foams possessing extremely high specific surface area and lots of randomly connected path inside the medium body can improve thermal performance of compact heat exchangers, especially in the two-phase bubbly flow. In this study, flow boiling in metal foam inserted channel is experimentally investigated with a focus on the bubbly flow regime. The channel of cross section 5mm by 50mm is used to study the effects of vertical-up flow. R245fa is studied as the operating fluid and heated water loop is used as a heating source. Boiling heat transfer coefficient and pressure drop properties across different types of metallic foam structure are discussed with the effects of the inlet vapor quality and the heat flux. In order to observe the bubble behavior though the metallic porous media, the visualization experiment was performed using a high speed camera. The results presented in this paper may help to understand the interior flow boiling heat transfer mechanism through the metallic porous media.
Kim教授简介：
Prof. KC Kim received his BA degree at Pusan National University, Korea in 1979. He received MS and Ph.D degree at KAIST, Korea in 1981 and 1987 respectively. Since 1983, he was hired as a faculty member in Pusan National University (PNU), Korea. He was invited as a visiting professor from Ottawa University in Canada for 1989-1990. He joined at the department of theoretical and applied mechanics in University of Illinois, Urbana-Champaign, USA as an invited professor for 1996-1997. He was invited as a special foreign professor from the University of Tokyo, Japan for 2009-2010. KC Kim was selected as a PNU Distinguished Professor in 2018. During 35 years at PNU, he has published about 580 refereed journal papers in Domestic and International Journals and supervised 198 MS and Ph.D students. On the basis of his research outcomes, he received the outstanding paper awards (1995, 2002) from KSME and KOSEF. In 2009 and 2016, he received the Academic award and the first Yeosong award from KSME. He received Nakayama award in 2012 and Asanuma award in 2014 based on contributions in world Visualization society. He is currently serving as an Editor in Chief for Journal of Visualization. In 2002, his laboratory has designated as a National Research laboratory from the Ministry of Science and Education of Korea. Prof. Kim established the MEMS/NANO Fabrication Center and served as the director from 2004-2009. In 2004, he was selected as a member of National Academy of Engineering of Korea. For 2008-2009, He was in charge of the president of Korean Society of Visualization. He was the Chairman of the 14th International Symposium on Flow Visualization which was held in Daegu, Korea, 2010. He was the Chairman of the 12th International Symposium on Particle Image Velocimetry which was held for June 18-22, 2017, Busan, Korea. His research interests include: Turbulence, Two-Phase Flows, Flow Visualization, PIV, LIF, PSP, TSP, CFD, Heat Transfer, Thermal System Simulation and Optimization, Next Generation Marine Engine, Organic Rankine Cycle Power System, Multi-scale Multi-physics Analysis and Measurement Techniques, Microfluidics, Bio-MEMS, Lattice Boltzmann Simulation, Solar Power, Cryogenics, Wind Turbine and Fuel Cell, and Wind Engineering.
