Professor Konstantina Vogiatzaki at the Lubbock Supporting Lecture 2023: Cool Fluid Dynamics: the weird world of very cold liquids

Cryogenic fluids are essential ingredients towards the solution of future challenges in energy sustainability (cryogenic energy storage, cryogenic hydrogen), space exploration (propellants for rockets), effective thermal management (cooling) and non-invasive cancer treatment (cryosurgery). Although the cryogenic science is more than 100 years old, very little is still known about the properties and phase transitions of cryogenic fluids under realistic operation conditions of commercial applications. The reason is that until now new technological developments relied solely on experiments. However, performing lab experiments with all the possible combinations of fluids and conditions to determine the optimum operability limits is very expensive and not always accurate, mainly because of the limitations of experimental techniques, safety issues relating to handling of cryogenic fluids, and lack of experimental equipment that can be operated in very low temperatures.

Konstantina describes a new route of providing insight into the unique dynamics of cryogenic fluids using Computational Fluid Dynamics models specifically tailored for ultra low temperature thermodynamic conditions. She presents an overview as to how these models can help us build new knowledge into the complex behaviour of cryogens over a range of scales (from molecular to macro scale) and a range of phases (gas, liquid and supercritical) in terms of (i) thermophysical properties and phase change mechanisms (ii) jet dynamics including turbulence effects.