Large eddy simulation of temporally developing juncture flows
โ Scribed by Madhu Sreedhar; Fred Stern
- Publisher
- John Wiley and Sons
- Year
- 1998
- Tongue
- English
- Weight
- 653 KB
- Volume
- 28
- Category
- Article
- ISSN
- 0271-2091
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โฆ Synopsis
Large eddy simulation (LES) results are reported for temporally developing solid -solid and solid -rigidlid juncture flows. A MacCormack-type scheme that is second-order in time, and fourth-order in space for the convective terms and second-order in space for the viscous terms, is used. The simulations are obtained for a low subsonic Mach number. The subgrid-scale stresses (SGS) are modeled using the dynamic modeling procedure. The turbulent flow field generated on a flat-plate boundary layer is used to initialize the juncture flow simulations. The results of the flat-plate boundary layer simulations are validated with experimental and direct numerical simulations (DNS) data. In juncture flow simulations, the presence of an adjacent solid-wall/rigid-lid boundary altered the mean and the turbulent field, setting up gradients in the anisotropy of normal Reynolds stresses resulting in the formation of turbulence-induced secondary vortices. The relative size of these secondary vortices and the distribution of mean and turbulent quantities are in qualitative agreement with the experimental observations for the solid -solid juncture. The overall distribution of the mean and turbulence quantities showed close resemblance between the solid-solid and the solid-rigid-lid junctures; except for the absence of a second vortical region near the rigid-lid boundary. In agreement with the experimental observations, it was found that the normalized anisotropy term exhibited similarity when plotted against the distance from the boundary, regardless of the type of boundary, i.e. solid-wall or rigid-lid. The turbulent kinetic energy increased near the rigid-lid boundary. While the surface normal velocity fluctuations decreased to zero at the rigid-lid boundary, the other two velocity components showed an increase in their energy, which is also consistent with the experimental observations.
๐ SIMILAR VOLUMES
A large-eddy simulation (LES) of transition in plane channel flow has been carried out. The LES results have been compared with those of a fine direct numerical simulation (DNS), and with those of a coarse DNS that uses the same mesh as the LES, but no residual stress model. While at the early stage