The Temperature and Pressure Dependencies of Fluid Properties: Implications for Achieving Ultra-high Rayleigh and Reynolds Numbers

The temperature and pressure dependencies of the thermodynamic and transport properties of helium are reviewed. This is done within the context of identifying thermodynamic states where maximum values of the Reynolds and Rayleigh numbers can be generated. The law of corresponding states provides a basis for comparing the properties of helium with those of sulfur hexafluoride, as well as, with those of more conventional fluids, such as water, air, and nitrogen. It is shown that helium provides access to higher Reynolds and Rayleigh numbers than any of the other fluids discussed.