Journal article
Incompressible variable-density turbulence in an external acceleration field
I Gat, G Matheou, D Chung, PE Dimotakis
Journal of Fluid Mechanics | CAMBRIDGE UNIV PRESS | Published : 2017
DOI: 10.1017/jfm.2017.490
Abstract
Dynamics and mixing of a variable-density turbulent flow subject to an externally imposed acceleration field in the zero-Mach-number limit are studied in a series of direct numerical simulations. The flow configuration studied consists of alternating slabs of high- and low-density fluid in a triply periodic domain. Density ratios in the range of are investigated. The flow produces temporally evolving shear layers. A perpendicular density-pressure gradient is maintained in the mean as the flow evolves, with multi-scale baroclinic torques generated in the turbulent flow that ensues. For all density ratios studied, the simulations attain Reynolds numbers at the beginning of the fully developed ..
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Awarded by U.S. Department of Energy
Funding Acknowledgements
The work is supported by DOE grant DE-NA0002382, the NSF Graduate Research Fellowship Program under grant DGE-1144469, the Caltech academic program, and the Caltech Northrop Chair in Aeronautics. Support was also provided by the AFOSR grant FA9550-12-1-0461, the Blue Waters Sustained-Petascale Computing Project, supported by NSF Awards OCI-0725070 and ACI-1238993, and the state of Illinois. Blue Waters is a joint effort of the University of Illinois at Urbana-Champaign and its National Center for Supercomputing Applications. Simulations performed on Blue Waters were under NSF PRAC award number ACI-1440083. Computations were also performed on the Caltech Zwicky computer cluster, supported by NSF MRI-R2 Award PHY-0060291 and by the Sherman Fairchild Foundation. The work was also supported by the Cray Trinity system of the Alliance for Computing at Extreme Scale (ACES), a partnership between Los Alamos National Laboratory and Sandia National Laboratories for the U.S. Department of Energy's NNSA. Data storage, visualization, and post-processing were facilitated by a computer cluster integrated by D. Lang, and developed through support by NSF MRI grant EIA-0079871, AFOSR DURIP grant FA9550-10-1-0553, and support by the AFOSR and DOE grants mentioned above. We'd like to thank C. Pantano for noting an additional term in the self-similar mass conservation equation contributed by the diffusion-induced velocity (4.3). We would finally like to acknowledge discussions with D. Meiron and D. Pullin, and a collaboration in the computations with C. Ott.