ar X iv : p hy si cs / 0 60 10 62 v 1 1 0 Ja n 20 06 Influence of turbulence on the dynamo threshold
نویسنده
چکیده
We use direct and stochastic numerical simulations of the magnetohydrodynamic equations to explore the influence of turbulence on the dynamo threshold. In the spirit of the Kraichnan-Kazantsev model, we model the turbulence by a noise, with given amplitude, injection scale and correlation time. The addition of a stochastic noise to the mean velocity significantly alters the dynamo threshold. When the noise is at small (resp. large) scale, the dynamo threshold is decreased (resp. increased). For a large scale noise, a finite noise correlation time reinforces this effect.
منابع مشابه
ar X iv : p hy si cs / 0 60 62 46 v 1 2 8 Ju n 20 06 Kolmogorov scaling in impassioned van Gogh paintings
We show that some impassioned van Gogh paintings display scaling properties similar to the observed in turbulent fluids, suggesting that these paintings reflect the fingerprint of turbulence with such a realism that is even consistent with the way that a mathematical model characterizes this phenomenon. Specifically, we show that the probability distribution function (PDF) of luminance fluctuat...
متن کاملar X iv : p hy si cs / 0 60 10 79 v 1 1 1 Ja n 20 06 Comparison of 87 Rb N - resonances for D 1 and D 2 transitions
We report an experimental comparison of three-photon-absorption resonances (known as “N resonances”) for the D1 and D2 optical transitions of thermal Rb vapor. We find that the D2 N -resonance has better contrast, a broader linewidth, and a more symmetric lineshape than the D1 N -resonance. Taken together, these factors imply superior performance for frequency standards operating on alkali D2 N...
متن کاملar X iv : p hy si cs / 0 60 62 30 v 1 2 6 Ju n 20 06 Enhanced Molecular Orientation Induced by Molecular Anti - Alignment
We explore the role of laser induced anti-alignment in enhancing molecular orientation. A field-free enhanced orientation via anti-alignment scheme is presented, which combines a linearly polarized femtosecond laser pulse with a half-cycle pulse. The laser pulse induces transient anti-alignment in the plane orthogonal to the field polarization, while the half-cycle pulse leads to the orientatio...
متن کاملar X iv : p hy si cs / 0 60 62 49 v 1 2 8 Ju n 20 06 Frequency shift of cesium clock transition due to blackbody radiation
We have performed ab initio calculations of the frequency shift induced by a static electric field on the cesium clock hyperfine transition. The calculations are used to find the frequency shifts due to blackbody radiation. Our result (δν/E = −2.26(2) × 10Hz/(V/m)) is in good agreement with early measurements and ab initio calculations performed in other groups. We present arguments against rec...
متن کاملar X iv : p hy si cs / 0 70 30 50 v 1 5 M ar 2 00 7 Excitation of zonal flow by the modulational instability in electron temperature gradient driven turbulence March 6 , 2007
The generation of large-scale zonal flows by small-scale electrostatic drift waves in electron temperature gradient(ETG) driven turbulence model is considered. The generation mechanism is based on the modulational instability of a finite amplitude monochromatic drift wave. The threshold and growth rate of the instability as well as the optimal spatial scale of zonal flow are obtained.
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2006