RT Journal Article ID 2ce2f43d5d2df008 A1 Hylin, E. C. A1 McDonough, James M. T1 Chaotic Small-Scale Velocity Fields as Prospective Models for Unresolved Turbulence in an Additive Decomposition of the Navier-Stokes Equations JF International Journal of Fluid Mechanics Research JO FMR YR 1999 FD 1999-12-01 VO 26 IS 5-6 SP 539 OP 567 AB A novel approach to turbulence modeling, based on unaveraged governing equations and direct modeling of small-scale fluctuating quantities via discrete nonlinear dynamical systems (chaotic algebraic maps), is presented and compared (structurally) with widely-used turbulence modeling and simulation methods. It is shown that this new approach, termed additive turbulent decomposition (ATD), is similar to large-eddy simulation in some respects, but yet is distinctly different in that ATD employs filtering of computed solutions (a straightforward signal-processing problem) rather than complicated filtering of governing equations. This obviates the need to model Reynolds stresses (they no longer occur in the equations); instead, subgrid-scale primitive variables, e.g., fluctuating velocity components, can be modeled directly, thus providing a much closer link to physical laboratory experiments. The requirements that must be imposed to construct such models are thoroughly discussed, and a specific realization of this modeling approach is derived in detail. PB Begell House LK https://www.dl.begellhouse.com/journals/71cb29ca5b40f8f8,5e12a65502d5a022,2ce2f43d5d2df008.html