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A Large-eddy Simulation of the Turbulent Flow in the Vicinity of an Upright Wall-mounted Half Cylinder and Aerodynamic Sound Prediction
| Content Provider | Semantic Scholar |
|---|---|
| Author | Lee, Sungjay |
| Copyright Year | 2002 |
| Abstract | The turbulent flow approaching an upright wall-mounted half cylinder has been numerically investigated by using LargeEddy Simulation. The formation and the downstream transport of horse-shoe vortex are numerically simulated and compared with experimental data. The interactions between horse-shoe vortex formed by reorientation of incoming vorticity and the Strouhal vortices in the near wake of the half cylinder are also examined in this study. The governing equations are formulated in terms of a structured, curvilinear grid system to accommodate the truncated deductive model proposed by Lee(1992) for the subgrid-scale turbulent motions. The present results are produced at a Reynolds number of 8.0×10, based on the cylinder diameter. The far-field sound is also computed using Lighthill’s acoustic analogy. This LES results are examined with our experimental data in terms of both the global and local characteristics such as mean drag and base pressure coefficients, vortex shedding frequencies, wall pressure and farfield noise spectra, which are measured in an acoustic windtunnel facility. NOMENCLATURE A surface area C0 sound speed CL lift coefficient CL mean square of lift coefficient (CP)b base pressure coefficient CS Smagorinsky constant D domain of the fluid , diameter of cylinder Fi fluctuating force per unit area G Gaussian filter function H height of computation domain L length of computation domain, length of cylinder lC correlation length (P) sound pressure Re Reynolds number RPP cross-correlation S viscous part of the stress tensor Skl resolved scale strain rate tensor St Strouhal number stress tensor U∞ free-stream velocity uk k-th component of u velocity V volume of cell element velocity vector W width of computation domain β fraction of the total surface ∆ width or characteristic length scale of filter δ displacement thickness φ physical dependent variable γ = αeE/αPE , α is the distance, centroid of correlation length, specific heat ratio η Kolmogorov scale λo vortex center distance λs primary separation distance ν = μ/ρ , kinematic viscosity νT subgrid-scale eddy viscosity ρ density σkl filtered viscous stress tensor τkl subgrid-scale stress tensor ξv vertical vortex center distance Ω integration domain − |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | https://www.acricfd.com/download/papers/FEDSM99_LES_HalfCylinder_AeroSound.pdf |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
