USE OF THE MIXING LENGTH CONCEPT TO CORRECTLY REPRODUCE VELOCITY PROFILES OF TURBULENT FLOWS

Since the viscous analogy of turbulence was introduced by Reynolds, ma ny formulations for turbulent viscosity have been proposed. One of the m, based on the mixing length concept, is investigated here in a broad er point of view. The mixing length concept was used to correctly mode l turbulent velocity profiles for irregular two-dimensional and three- dimensional domains. Two cases of study were investigated for this pur pose: a simple two-dimensional aerodynamic problem and a more complica ted three-dimensional hydraulic problem. Results showed that the use o f a constant viscosity fails to correctly reproduce experimental obser vations. On the other hand, the use of the mixing length concept leads to a good agreement between the measured and predicted values.