Effects of Wall Topology on Statistics of Cube-Roughened Wall Turbulence
نویسندگان
چکیده
In this work, we carried out roughness-resolved direct numerical simulations of cube-roughened turbulent channel flows to investigate the effects aligned and staggered arrangements, element spacings, orientations on statistics rough-wall turbulence. The results show that equivalent sandgrain roughness, Reynolds stresses dispersive are affected by spacings arrangements in different ways depending cube orientations. Placing roughness elements a way general increases unless when element–element interaction is insignificant for orientation with wakes short length. As normal streamwise component (both normalized total friction velocity), placing decreases their maximal values compared arrangements. spacing maximums stresses, similar trends observed increasing l/r (where r height) from 2.0 2.8. When further 2.8 3.5, however, greater components larger all considered surfaces. For turbulence wake element, certain similarities spacings.
منابع مشابه
Numerical Study of Reynolds Number Effects on Flow over a Wall-Mounted Cube in a Channel Using LES
Turbulent flow over wall-mounted cube in a channel was investigated numerically using Large Eddy Simulation. The Selective Structure Function model was used to determine eddy viscosity that appeared in the subgrid scale stress terms in momentum equations. Studies were carried out for the flows with Reynolds number ranging from 1000 to 40000. To evaluate the computational results, data was compa...
متن کاملHigh Reynolds number effects in wall turbulence
A review of recent discoveries from high Reynolds number studies of turbulent boundary layers is given. The emergent regime of very large-scale structures in the logarithmic region and their subsequent influence on the near-wall cycle challenges many of the previously held assumptions regarding scaling of turbulent boundary layers at high Reynolds numbers. Experimental results are presented to ...
متن کاملReynolds number effects on scale energy balance in wall turbulence
Related Articles Lagrangian evolution of the invariants of the velocity gradient tensor in a turbulent boundary layer Phys. Fluids 24, 105104 (2012) Effects of moderate Reynolds numbers on subsonic round jets with highly disturbed nozzle-exit boundary layers Phys. Fluids 24, 105107 (2012) Particle transport in a turbulent boundary layer: Non-local closures for particle dispersion tensors accoun...
متن کاملthe effects of planning on accuracy and complexity of iranian efl students’ written narrative task performance
this study compared the different effects of form-focused guided planning vs. meaning-focused guided planning on iranian pre-intermediate students’ task performance. the study lasted for three weeks and concentrated on eight english structures. forty five pre-intermediate iranian students were randomly assigned to three groups of guided planning focus-on-form group (gpfg), guided planning focus...
15 صفحه اولذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Boundary-Layer Meteorology
سال: 2022
ISSN: ['0006-8314', '1573-1472']
DOI: https://doi.org/10.1007/s10546-022-00760-3