NUMERICAL STUDIES OF A HIGHLY ANISOTROPIC RECIRCULATION

6th International Symposium on Turbulence and Shear Flow Phenomena

BUBBLE IN A THIN FLAT PLATE AT SMALL ANGLE OF ATTACK ; Luiz Eduardo B. Sampaio ; Angela O. Nieckele ; Department of Mechanical Engineering

PID  :  127626

来源: CEUR

【 摘 要 】

One of the situations that evidences some fundamen tal weakness of Reynolds Average Navier Stokes (RANS) approach to turbulence modeling is that involving highly anisotropic turbulence structures, such as that observed in long and thin recirculation zone in a high Reynolds number aerodynamic ow. Previous numerical studies tried to re produce the experimental results from Crompton (2001) for a leadingedge separation in a thin at plate at small inci dence, using several RANS models. None of these models proved to be able of capturing some very important features of this ow, and it was suggested that LargeEddy Simu lations would not only provide more accurate results, but also allow a better physical understanding of the turbulence mechanisms. Therefore, in this work LargeEddy Simula tions is employed to determine the ow eld over a thin at plate, and results are compared with experimental data from Crompton (2001), with two completely dierent approaches for subgrid modeling: the traditional Dynamic Smagorin sky model from Germano (1999), and a new one, based on an advective forcing approach (Sampaio et al, 2007). Both approaches showed a very good agreement with the exper imental data, and were able to capture all the important structures, such as boundary layer separation and reattach ment, relaminarization, primary and secondary recirculation