EAGER: Experimental Methods and Measurements of Anomalous Properties of Supercritical Fluids and their Mixtures

University Of North Texas, Denton TX

Investigators

Abstract

Fluids under supercritical conditions, where distinct liquid and gas phases no longer exist, are good candidates for enhanced thermal transport and effective thermal control and management. Supercritical heat exchangers are promising solutions for direct solar energy conversion, power generation, thermal management of space systems, to name a few. However, research on supercritical heat transfer has been limited because of the lack of understanding of anomalous behaviors, characterized by large variations in thermophysical properties in a region around the critical point, and the associated thermal oscillations and fluctuations. This EAGER project will develop experimental capabilities to measure supercritical properties in the anomalous region to improve the fundamental understanding of supercritical fluids and their performance in heat transfer applications. This EAGER project seeks to explore: (i) the use of anomalous behavior to achieve enhanced heat transfer, (ii) thermal management and control using a small variation in supercritical pressure, and (iii) change in critical temperature of supercritical fluid mixture to tune the temperature at which the heat dissipates. The project tasks are to obtain experimental data on critical properties for mixtures of CO2 with Ar and R134a and conduct natural convection experiments to demonstrate the effect of temperature and pressure in the anomalous region. If successful, this EAGER project could build the foundation of using supercritical fluid mixtures for heat dissipation at extreme temperatures and enable applications in solar thermal and power generation systems. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.