Modelling two- and three-dimensional separation from curved surfaces with anisotropy-resolving turbulence closures

• Published in: International journal of heat and fluid flow 2004-06, Vol.25 (3), p.499-512
• Main Authors: Wang, C., Jang, Y.J., Leschziner, M.A.
• Format: Article
• Language: English
• Subjects: Curved surfaces; Exact sciences and technology; Flows in ducts, channels, nozzles, and conduits; Fluid dynamics; Fundamental areas of phenomenology (including applications); Non-linear eddy-viscosity models; Physics; Reynolds-stress models; Separation; Turbulence modelling; Turbulence simulation and modeling; Turbulent flows, convection, and heat transfer
• ISSN: 0142-727X; 1879-2278
• DOI: 10.1016/j.ijheatfluidflow.2004.02.009

The ability of non-linear eddy-viscosity and second-moment models to predict separation from two- and three-dimensional curved surfaces is examined on the basis of computations for two flows that are geometrically akin: one separating from periodically-spaced, two-dimensional `hills' in a plane channel, and the other from a three-dimensional hill in a duct. One major objective is to examine whether the predictive performance in 3-d (three-dimensional) conditions relates to that in 2-d (two-dimensional) flow. In the former, the separation pattern is far more complicated, being characterised by multiple vortical structures associated with `open' separation. The predicted separation behaviour in the 2-d flow differs significantly from model to model, with only one non-linear model among those examined performing well, this variant formulated to adhere to the two-component wall limit. In 3-d separation, none of the models gives a credible representation of the complex multi-vortical separation pattern.