Effect of weak rotation on large-scale circulation cessations in turbulent convection.
نویسندگان
چکیده
We investigate the effect of weak rotation on the large-scale circulation (LSC) of turbulent Rayleigh-Bénard convection, using the theory for cessations in a low-dimensional stochastic model of the flow previously studied. We determine the cessation frequency of the LSC as a function of rotation, and calculate the statistics of the amplitude and azimuthal velocity fluctuations of the LSC as a function of the rotation rate for different Rayleigh numbers. Furthermore, we show that the tails of the reorientation PDF remain unchanged for rotating systems, while the distribution of the LSC amplitude and correspondingly the cessation frequency are strongly affected by rotation. Our results are in close agreement with experimental observations.
منابع مشابه
Rotations and cessations of the large-scale circulation in turbulent RayleighBnard convection
We present a broad range of measurements of the angular orientation θ0(t) of the large-scale circulation (LSC) of turbulent Rayleigh-Bénard convection as a function of time. We used two cylindrical samples of different overall sizes, but each with its diameter nearly equal to its height. The fluid was water with a Prandtl number of 4.38. The time series θ0(t) consisted of meanderings similar to...
متن کاملRotations and cessations of the large-scale circulation in turbulent Rayleigh-Bénard convection
We present a broad range of measurements of the angular orientation θ0(t) of the largescale circulation (LSC) of turbulent Rayleigh-Bénard convection as a function of time. We used two cylindrical samples of different overall sizes, but each with its diameter nearly equal to its height. The fluid was water with a Prandtl number of 4.38. The time series θ0(t) consisted of meanderings similar to ...
متن کاملLarge-scale circulation model for turbulent Rayleigh-Bénard convection.
A model for the large-scale-circulation (LSC) of turbulent Rayleigh-Bénard convection in cylindrical samples is presented. It consists of two physically motivated stochastic ordinary differential equations, one each for the strength and the azimuthal orientation of the LSC. Stochastic forces represent phenomenologically the influence of turbulent fluctuations. Consistent with measurements, the ...
متن کاملReorientation of the large-scale circulation in turbulent Rayleigh-Bénard convection.
We present measurements of the orientation theta0(t) of the large-scale circulation (LSC) of turbulent Rayleigh-Bénard convection in cylindrical cells of aspect ratio 1. Theta0(t) undergoes irregular reorientations. It contains reorientation events by rotation through angles delta theta with a monotonically decreasing probability distribution p(delta theta), and by cessations (where the LSC sto...
متن کاملRare fluctuations and large-scale circulation cessations in turbulent convection.
In turbulent Rayleigh-Bénard convection, a large-scale circulation (LSC) develops in a nearly vertical plane and is maintained by rising and falling plumes detaching from the unstable thermal boundary layers. Rare but large fluctuations in the LSC amplitude can lead to extinction of the LSC (a cessation event), followed by the reemergence of another LSC with a different (random) azimuthal orien...
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 109 7 شماره
صفحات -
تاریخ انتشار 2012