On the influence of numerical schemes and subgrid–stress models on large eddy simulation of turbulent flow past a square cylinder

Abstract

SUMMARYIn uence of ÿnite di erence schemes and subgrid-stress models on the large eddy simulation calculation of turbulent ow around a blu body of square cylinder at a laboratory Reynolds number, has been examined. It is found that the type and the order of accuracy of ÿnite-di erence schemes and the subgrid-stress model for satisfactory results are dependent on each other, and the grid resolution and the Reynolds number. Using computational grids manageable by workstation-level computers, with which the near-wall region of the separating boundary layer cannot be resolved, central-di erence schemes of realistic orders of accuracy, either fully conservative or non-conservative, su er stability problems. The upwind-biased schemes of third order and the Smagorinsky eddy-viscosity subgrid model can give reasonable results resolving much of the energy-containing turbulent eddies in the boundary layers and in the wake and representing the subgrid stresses in most parts of the ow. Noticeable improvements can be obtained by either using higher order di erence schemes, increasing the grid resolution and=or by implementing a dynamic subgrid stress model, but each at a cost of increased computational time. For further improvements, the very small-scale eddies near the upstream corners and in the laminar sublayers need to be resolved but would require a substantially larger number of grid points that are out of the range of easily accessible computers.

Modeling turbulent flow over fractal trees with renormalized numerical simulation

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Large Eddy Simulation of Flows Associated with Offshore Oil and Gas Pipeline

“…In this method large eddies are computed (resolved) and smallest sub-gird-scale eddies are model [11]. This is based on Kolmogorov's theory on turbulence which makes the assumption that large eddies of the flow are dependent on the flow geometry, whereas smaller eddies are self-similar and have a universal character.…”

Hybrid LES — Review and assessment

“…Many newer models such as one equation model (Shumann, 1975;Yoshizawa & Horiuti, 1985), scale similarity type models (Bardina et al 1980), dynamic model of eddy viscosity type (Germano et al 1991), mixed dynamic models (Zang et al 1993;Vreman et al 1994), one equation dynamic models (Ghosal et al 1995;Davidson, 1997) and dynamic two-parameter mixed model (Horitui, 1997;Morinishi & Vasilyev, 2001) are then introduced. Study of SGS models to engineering and topographical problems has also been carried out (Vengadesan & Nakayama, 2001;Nakayama & Vengadesan, 2002).…”