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Anisotropic Eddy Viscosity Modeling for Application to Industrial Engineering Internal Flows
Emilio Baglietto and Hisashi Ninokata

An improved realizable anisotropic turbulence model is proposed for application to industrial thermal hydraulics simulation, and in particular to internal flows such as those in pipes or in flow channels of complicated geometry. A cubic formulation of the stress-strain correlation is adopted to overcome the typical limitations related to the eddy-viscosity assumption, and an optimized low-Reynolds-number formulation based on Direct Numerical Simulation (DNS) data is employed to produce the correct damping of the turbulent viscosity in the near wall region. The model capabilities are assessed on a range of relevant flow cases, showing the conspicuous improvements in capturing the effects of anisotropy as well as of streamline curvature and rotation. The wider generality of the proposed closure, being derived from improved physical description contained in the non-linear stress strain formulation, is further demonstrated by the remarkable enhancement in the predictions of flows involving separation and reattachment.

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