A report discusses direct numerical simulations (DNS) of a developing mixing layer between nitrogen and heptane initially at different temperatures and initially flowing at different velocities under supercritical conditions. The usual conservation equations for a binary fluid, along with the Peng-Robinson equation of state for the heptane/nitrogen mixture, were solved numerically and the solutions analyzed. Departures from perfect-gas and ideal-mixture conditions were quantified by compression factors and mass-diffusion factors, both of which exhibited decreases from unity.

This work was done by Josette Bellan, Kenneth Harstad, and Richard Miller of Caltech for NASA's Jet Propulsion Laboratory. To obtain a copy of the report, "Direct Numerical Simulations of Supercritical Fluid Mixing Layers Applied to Heptane - Nitrogen," access the Technical Support Package (TSP) free on-line at www.nasatech.com/tsp  under the Physical Sciences category.