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Artikel

Renaissance in turbulent boundary layers, and impact in modeling wall-bounded turbulence

Författare: Vinuesa, R., Rozier, P, Duncan, R., Nagib, H.M.
Dokumenttyp: Artikel
Tillstånd: Publicerad
Tidskrift: 41st AIAA Fluid Dynamics Conference and Exhibit 27 - 30 June 2011, Honolulu, Hawaii
Volym:    3241
År: 2011

Abstract

The study of high Reynolds number wall-bounded turbulent flows has become a very active area of research in the past decade. Recent advances in experimental and computa-tional results have challenged our understanding, leading to the reassessment of the scaling and asymptotic behavior especially for boundary layer ows. In this study we character- ize four di erent localized pressure-gradient con gurations by computing them using four RANS turbulence models (SA, k ?? , SST and RSM), and comparing their predictions with experimental results of the independently measured mean ow quantities and wall shear stress. The pressure gradients were imposed on high Reynolds number, two-dimensional turbulent boundary layers developing on a at plate by changing the ceiling geometry of the 10-meter long test section. Two converging humps (at x = 2:1 and x = 5:5 m from the leading edge of the plate) and two diverging humps at the same locations were considered. Our computations showed that the SST model produced the best agreement with the ex-periments. The eff ect of numerical transition (a procedure by which the code, with thespeci c turbulence model, transforms the initial laminar boundary conditions into inflow conditions to characterize the turbulent ow) on the models performance was investigated by solving a zero pressure gradient con guration. We found that this transition process causes the major di erences between the various models, thereby, highlighting the need for models representative of true transition in computational codes. Pressure gradient eff ects were studied separately by imposing turbulent pro les from the SST computations as in-ow conditions for the rest of the models. The SA and k ??  models provided good results under adverse and favorable pressure gradient flow con gurations respectively.