Characteristics of plumes forming in turbulent thermal convection

نویسندگان
چکیده

برای دانلود رایگان متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Extraction of plumes in turbulent thermal convection.

We present a scheme to extract the velocity of buoyant structures in turbulent thermal convection from simultaneous local velocity and temperature measurements. Applying this scheme to measurements taken at positions within the convection cell where the buoyant structures are dominated by plumes, we obtain the temperature dependence of the plume velocity and understand our results using the equ...

متن کامل

Thermal signature of plumes in turbulent convection: The skewness of the derivative.

We present experimental evidence that, in the hard turbulence regime of Rayleigh-Bénard convection, the temperature fluctuations are produced by buoyancy, despite the presence of a mean horizontal flow at the plates. In a convection cell of aspect ratio 1, we measure the temperature time derivative for Ra from 2310 to 1310, which is skewed toward the negative in the region outside the cold ther...

متن کامل

Physical and geometrical properties of thermal plumes in turbulent Rayleigh–Bénard convection

We present a systematic experimental study of geometric and physical properties of thermal plumes in turbulent Rayleigh–Bénard convection using the thermochromic-liquid-crystal (TLC) technique. The experiments were performed in three water-filled cylindrical convection cells with aspect ratios 2, 1 and 0.5 and over the Rayleigh number range 5× 107 6 Ra 6 1011. TLC thermal images of horizontal p...

متن کامل

From laminar plumes to organized flows: the onset of large-scale circulation in turbulent thermal convection

We report an experimental study on the onset of the large-scale coherent mean flow in Rayleigh–Bénard turbulent convection. Shadowgraph and particle image velocimetry techniques are used to visualize the motion of thermal plumes and measure the velocity of the plumes and of the ‘background’ flow field, as the fluid motion evolves from quiescent to steady state. The experiment reveals the dynami...

متن کامل

Breakdown of wind in turbulent thermal convection.

We report experiments on turbulent Rayleigh-Bénard convection of air in a cylindrical large-scale facility with a diameter of 7 meters and Rayleigh numbers up to Ra approximately 10(12). The facility is used to explore the structure of the large-scale circulation for continuously varying aspect ratios between Gamma approximately 1 and Gamma approximately 10. Using autocorrelation functions deri...

متن کامل

ذخیره 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: PROCEEDINGS OF THE JAPANESE CONFERENCE ON HYDRAULICS

سال: 1983

ISSN: 1884-9164,0913-4131

DOI: 10.2208/prohe1975.27.159