Swirling-strength based large eddy simulation of turbulent flowaround single square cylinder at low Reynolds numbers∗
Swirling-strength based large eddy simulation of turbulent flowaround single square cylinder at low Reynolds numbers∗
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DOI：
10.1007/s10483-014-1847-7
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发表时间：
2014
期刊：
影响因子：
--
通讯作者：
Li Yinglin
中科院分区：
文献类型：
--
作者：
Zhu Zuojin;Niu Jianlei;Li Yinglin
In view of the fact that large scale vortices play the substantial role of.momentum transport in turbulent flows, large eddy simulation (LES) is considered as.a better simulation model. However, the sub-grid scale (SGS) models reported so far.have not ascertained under what flow conditions the LES can lapse into the direct numerical.simulation. To overcome this discrepancy, this paper develops a swirling strength.based the SGS model to properly model the turbulence intermittency, with the primary.characteristics that when the local swirling strength is zero, the local sub-grid viscosity.will be vanished. In this paper, the model is used to investigate the flow characteristics.of zero-incident incompressible turbulent flows around a single square cylinder (SC).at a low Reynolds number range Re ∈ [103, 104]. The flow characteristics investigated.include the Reynolds number dependence of lift and drag coefficients, the distributions.of time-spanwise averaged variables such as the sub-grid viscosity and the logarithm of.Kolmogorov micro-scale to the base of 10 at Re = 2 500 and 104, the contours of spanwise.and streamwise vorticity components at t = 170. It is revealed that the peak value of.sub-grid viscosity ratio and its root mean square (RMS) values grow with the Reynolds.number. The dissipation rate of turbulent kinetic energy is larger near the SC solid walls..The instantaneous factor of swirling strength intermittency (FSI) exhibits some laminated.structure involved with vortex shedding.
