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15 mins
Direct Numerical Simulations of Turbulent Mixing Layers Between Two Fluids of Large Density Difference
Jon Baltzer, Daniel Livescu
Session: Transport and mixing 1
Session starts: Wednesday 26 August, 13:30
Presentation starts: 13:45
Room: Room I

Jon Baltzer (Los Alamos National Laboratory)
Daniel Livescu (Los Alamos National Laboratory)

In numerous practical applications, shear layers exist between fluids of strongly differing densities. At high Atwood numbers, the large variations in density introduce important effects that have recently been observed in other flows (e.g., Livescu and Ristorcelli, J. Fluid Mech., 605:145–180, 2008). To investigate the inertial variable density effects on the instability growth and structure of mixing layers, we perform very large Direct Numerical Simulations of planar mixing layers between two miscible fluids, each with different density. The DNS domain sizes accommodate large extents of mode pairings, based on the most unstable modes obtained from linear stability analysis. The results display the overall statistical effects on the turbulence and mixing, as well as the structural differences that occur as Atwood number is varied. In particular, significant asymmetries are introduced by the differences in the densities of the mixing layer streams.