This report describes a study of threedimensional, temporal mixing layers between different fluids initially flowing at different velocities under supercritical conditions. The study involved direct numerical simulations by use of a validated mathematical model of high-pressurefluid behavior that has been described in a number of prior NASA Tech Briefs articles. In some cases, the fluids were heptane and nitrogen; in other cases, they were hydrogen and oxygen. In all these simulations, the mixing layers underwent transition to turbulence.
This work was done by Josette Bellan and Nora Okong’o of Caltech for NASA’s Jet Propulsion Laboratory. To obtain a copy of the report, “Characteristics of Supercritical Transitional Temporal Mixing Layers,” access the Technical Support Package (TSP) free online at www.nasatech.com/tsp under the Physical Sciences category. NPO-30292
