Dynamics of Large Eddies in Turbulent Channel Flows
A turbulence model that describes dynamics of large, characteristic eddies in inhomogeneous flows is proposed; two closure parameters are initially undetermined. To determine the optimum values of these parameters, the present model is applied to channel flows at two Reynolds numbers. The nature of the closure parameters and their effects upon predicted Reynolds stresses and other turbulence structural quantities are examined and optimum values are suggested. It is demonstrated that the current Large-Eddy Interaction Model not only predicts Reynolds stresses reasonably but also presents an opportunity to illuminate typical characteristic motions of large-scale turbulence and the phenomenological aspects of engineering models for the two Reynolds numbers investigated. In addition, analysis of the spatial correlation integral suggests that a strange attractor found in the fully-developed channel flow has a low fractal dimension.