Grant: Discovery Grants Program - Individual

<p>SuperCritical Fluids (SCFs) are fluids at pressures above critical pressure. SCFs exhibit a unique set of properties like peaks in specific heat, thermal conductivity and coefficient of thermal expansion; zero surface tension; high diffusivity and compressibility; which make them ideal for use in a variety of industrial and laboratory applications. The application of SCFs requires an understanding of the fundamentals of their thermophysical properties and behavior. At critical and SC Pressures (SCPs) a fluid is considered a single-phase substance despite the fact that all thermophysical properties undergo significant variations within the critical and pseudocritical regions. Near the critical point, these changes are dramatic. In the vicinity of pseudocritical points with an increase in pressure, these changes become less pronounced.<br /> Specifics of SCF properties have significant effect on Heat Transfer (HT) and Pressure Drop (PD) at these conditions. Despite more than 60 years of active research into SCFs and their characteristics, many of physical phenomena and behavioral characteristics are not fully understood (for example, improved and deteriorated HT regimes, pseudo-boiling, pseudo-film boiling, etc.). Solid knowledge and understanding of thermophysical properties, HT and PD specifics at critical and SCPs are very important for a safe and efficient use of SCFs in various industries. The applicant has made significant progress investigating specifics of SCFs thermophysical properties and HT/PD that have resulted in numerous publications and the first technical book on HT and PD at SCPs. His latest HT correlation, developed together with his students, for SC water flowing in tubes is currently the most accurate one when compared to other correlations developed within the last 50 years. The proposed research, which will include analytical, numerical, Computational Fluid Dynamics (CFD) and experimental work, is based on his extensive expertise on properties and HT/PD specifics of SC water, carbon dioxide, helium and freons and various industrial applications of these SCFs. The objective of this research program is to broaden our knowledge of the fundamental behavior and various phenomena of SCFs and develop a scientific foundation for understanding parameters that govern specifics of SCFs.</p> <p>One of the largest industrial applications of an SCF is extensive use of SC water in power industry in SCP coal-fired power plants. However, there are many other areas of application for SCFs including: the use of near-critical helium to cool coils of SC electromagnets; the use of SC carbon dioxide as a refrigerant; the use of a SC cycle for the transformation of geothermal energy into electricity; etc. The implementation of SCFs (SC water, helium and carbon dioxide) is also anticipated in the nearest future in next generation or Generation IV nuclear reactors and/or their power-conversion cycles. </p>