کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
656295 | 1457681 | 2006 | 12 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: A computational study of the near-field generation and decay of wingtip vortices A computational study of the near-field generation and decay of wingtip vortices](/preview/png/656295.png)
The numerical prediction of the downstream trailing vortex shed from an aircraft wingtip is a particularly challenging CFD task because, besides predicting the development of the strong vortex itself, one needs to compute accurately the flow over the wing to resolve the boundary layer roll-up and shedding which provide the initial conditions for the free vortex.Computations are here reported of the flow over a NACA 0012 half-wing with rounded wing tip and the near-field wake as measured by [Chow, J.S., Zilliac, G., Bradshaw, P., 1997. Turbulence measurements in the near-field of a wingtip vortex. NASA Tech Mem 110418, NASA.]. The aim is to assess the performance of two turbulence models which, in principle, might be seen as capable of resolving both the three dimensional boundary layer on the wing and the generation and near-field decay of the strongly accelerated vortex that develops from the wingtip. Results using linear and non-linear eddy-viscosity models are presented, but these both exhibit a far too rapid decay of the vortex core. Only a stress-transport (or second-moment) model that satisfies the “two-component limit”, [Lumley, J.L., 1978. Computational modelling of turbulent flows. Adv. Appl. Mech. 18, 123–176.], reproduces the principal features found in the experimental measurements.
Journal: International Journal of Heat and Fluid Flow - Volume 27, Issue 4, August 2006, Pages 684–695