کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1896496 1044435 2010 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Statistics of velocity gradients in wall-bounded shear flow turbulence
موضوعات مرتبط
مهندسی و علوم پایه ریاضیات ریاضیات کاربردی
پیش نمایش صفحه اول مقاله
Statistics of velocity gradients in wall-bounded shear flow turbulence
چکیده انگلیسی

The statistical properties of velocity gradients in a wall-bounded turbulent channel flow are discussed on the basis of three-dimensional direct numerical simulations. Our analysis is concentrated on the trend of the statistical properties of the local enstrophy ω2(x,t) and the energy dissipation rate ϵ(x,t) with increasing distance from the wall. We detect a sensitive dependence of the largest amplitudes of both fields (which correspond with the tail of the distribution) on the spectral resolution. The probability density functions of each single field as well as their joint distribution vary significantly with increasing distance from the wall. The largest fluctuations of the velocity gradients are found in the logarithmic layer. This is in agreement with recent experiments which observe a bursting of hairpin vortex packets into the logarithmic region.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Physica D: Nonlinear Phenomena - Volume 239, Issue 14, 15 July 2010, Pages 1258–1263
نویسندگان
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