Analysis and modeling of subgrid scalar mixing using numerical data
نویسنده
چکیده
Direct numerical simulations (DNS) of passive scalar mixing in isotropic turbulence is used to study, analyze and, subsequently, model the role of small (subgrid) scales in the mixing process. In particular, we attempt to model the dissipation of the large scale (supergrid) scalar uctuations caused by the subgrid scales by decomposing it into two parts: (i) the e ect due to the interaction among the subgrid scales, E>> ; and, (ii) the e ect due to interaction between the supergrid and the subgrid scales, E>< . Model comparison with DNS data shows good agreement. This model is expected to be useful in the large eddy simulations of scalar mixing and reaction. This research was supported by the National Aeronautics and Space Administration under NASA Contract No. NAS119480 while the authors were in residence at the Institute for Computer Applications in Science and Engineering (ICASE), NASA Langley Research Center, Hampton, VA 23681-0001.
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