Large-eddy simulation of transitional flows using a co-located grid
|Langari, Mostafa, Yang, Zhiyin and Page, Gary J.
A large-eddy simulation (LES) of a transitional separated flow over a plate with a semi-circular leading at low (<0.2%) and high (5.6%) free-stream turbulence (FST) has been performed, using a co-located grid with the Rhie–Chow pressure smoothing. A numerical trip is used to produce a high FST level and a dynamic subgrid-scale model is also employed in the current study. The entire transition process leading to breakdown to turbulence has been shown clearly by the flow visualisations using instantaneous spanwise vorticities, and the differences between the low- and high-FST cases are clearly visible. Coherent structures are also visualised using isosurfaces of the Q-criterion, and for the high-FST case, the spanwise-oriented quasi-two-dimensional rolls, which are clearly present in the low-FST case, are not visible anymore. Detailed quantitative comparisons between the present LES results and experimental data and the previous LES results at low FST using a staggered grid have been done and a good agreement has been obtained, indicating that the current LES using a co-located grid with pressure smoothing can also predict transitional flows accurately.
|LES; Transition; Co-located grid; Pressure smoothing; Transitional flows
|International Journal of Computational Fluid Dynamics
|Taylor & Francis
|Digital Object Identifier (DOI)
|Web address (URL)
|12 Jul 2013
|Publication process dates
|17 Oct 2016, 19:53
Archived with thanks to International Journal of Computational Fluid Dynamics
|University of Sussex, Brighton, UK and University of Derby, UK
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