Anisotropy of spatiotemporal decorrelation in electrohydrodynamic turbulence.
نویسندگان
چکیده
Nonlinear straining and random sweeping spatiotemporal decorrelation properties, originally introduced as the main processes for turbulent fluctuations decorrelation in usual fluid flows, have been observed experimentally in anisotropic electroconvective turbulence generated in a nematic liquid crystal under the action of an external oscillating electric field. A transition between both processes occurs when the instability is driven toward states of increasing complexity, thus showing that decorrelation mechanisms in turbulent media are more universal than naively expected. A model for both decorrelation mechanisms is introduced, its comparison with experimental results providing an estimate of the characteristic sweeping velocity.
منابع مشابه
Anomalous viscosity of the quark-gluon plasma
The shear viscosity of the quark-gluon plasma is predicted to be lower than the collisional viscosity for weak coupling. The estimated ratio of the shear viscosity to entropy density is rather close to the ratio calculated by N = 4 super Yang–Mills theory for strong coupling, which indicates that the quark-gluon plasma might be strongly coupled. However, in the presence of momentum anisotropy, ...
متن کاملOn the anisotropy of the turbulent passive scalar in the presence of a mean scalar gradient
We investigate the origin of the scalar gradient skewness in isotropic turbulence on which a mean scalar gradient is imposed. The problem of the advection of an anisotropic scalar field is reformulated in terms of the advection of an isotropic vector field. For this field triadic closure equations are derived. It is shown how the scaling of the scalar gradient skewness depends on the choice of ...
متن کاملInternal combustion engines in cylinder flow simulation improvement using nonlinear k-ε turbulence models
The purpose of this paper is to studying nonlinear k-ε turbulence models and its advantages in internal combustion engines, since the standard k-ε model is incapable of representing the anisotropy of turbulence intensities and fails to express the Reynolds stresses adequately in rotating flows. Therefore, this model is not only incapable of expressing the anisotropy of turbulence in an engine c...
متن کاملDisentangling inertial waves from eddy turbulence in a forced rotating-turbulence experiment.
We present a spatiotemporal analysis of a statistically stationary rotating-turbulence experiment, aiming to extract a signature of inertial waves and to determine the scales and frequencies at which they can be detected. The analysis uses two-point spatial correlations of the temporal Fourier transform of velocity fields obtained from time-resolved stereoscopic particle image velocimetry measu...
متن کاملDecorrelation of Edge Plasma Turbulence at the Transition from Low- to High-Con nement Mode in the DIII{D Tokamak
The modi cation of turbulence in the edge plasma of the DIII{D tokamak at the transition from the low to the high mode of con nement is investigated with a phase-contrast imaging diagnostic. The amplitude and radial correlation length of the turbulence in the con nement region decrease at the transition, whereas the decorrelation time increases. The transition model of Biglari, Diamond, and Ter...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Physical review letters
دوره 106 11 شماره
صفحات -
تاریخ انتشار 2011