9522968 Kudaravalli This proposal supports the collaboration of Dr. Ravikumar Kudaravalli of the Department of Chemical Engineering at the University of California, Los Angeles and Professor Yoichi Matsubara of the Atomic Energy Research Institute (AERI) at the Nihon University, Chiba. Project funding will enable Dr. Kudaravalli to spend one year in Japan, resident at Nihon University, in order to investigate the thermal and fluid dynamics phenomena for design of cryogenic pulse tube cooler components for optimum performance. Dr. Kudaravalli has previously investigated the heat transfer, fluid dynamics and thermodynamic aspects of various cryogenic systems in general and heat exchangers and regenerators of cryocoolers including pulse tube coolers in particular. Professor Matsubara is one of the leading researchers in the pulse tube cryocooler area. He has pushed the technology further by multistaging of the cooler and by invention of the regenerative tube. Professor Matsubara's demonstration of liquid helium temperatures (3.6 K) is the record low temperature ever produced by a pulse tube cryocooler. Dr. Kudaravalli will combine his expertise with that of Professor Matsubara to study the thermal and fluid dynamics phenomena in cryogenic pulse tube coolers achieving optimum performance. This proposal brings together research scientists from two countries working in the area of advanced cryogenic cooler technology. The U.S. scientist will have the opportunity to become familiar with research techniques, equipment and facilities at AERI while contributing to the overall research effort. Therefore, this proposal fulfills the objectives of the program in its exchange and transfer of scientific knowledge through an international collaboration. ***
