Thermal plume turbulence

نویسندگان

  • A. Celani
  • A. Mazzino
چکیده

A two-dimensional Boussinesq model of thermal convection is investigated by numerical simulations. The turbulent heat transport is mainly due to thermal plumes. It is shown that their thin, wrinkled interfaces control the statistics of large temperature excursions. Away from the interfaces, the temperature fluctuations are strongly suppressed and the field in those regions is well mixed. Their statistical signature is in the low-order moments of the temperature increments, whose scaling exponents depend linearly on the order. © 2001 American Institute of Physics. @DOI: 10.1063/1.1375145#

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

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Role of mixing in the structure and evolution of a buoyant discharge plume

[1] A field study to examine the near-field structure of a buoyant discharge plume, and the turbulent mixing associated with its evolution, was conducted in Mount Hope Bay near Somerset, Massachusetts. The study focused on a 50 m/s thermal discharge, approximately 5 C warmer than ambient waters, emanating from an electrical generating facility. The discharge enters the Bay through a 10 m wide s...

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

Comparison of Turbulent Thermal Diffusivity and Scalar Variance Models

In this study, several variable turbulent Prandtl number formulations are examined for boundary layers, pipe flow, and axisymmetric jets. The model formulations include simple algebraic relations between the thermal diffusivity and turbulent viscosity as well as more complex models that solve transport equations for the thermal variance and its dissipation rate. Results are compared with availa...

متن کامل

The role of turbulence stress divergence in decelerating a river plume

[1] Turbulence controls the composition of river plumes through mixing and alters the plume’s trajectory by diffusing its momentum. While believed to play a crucial role in decelerating river-source waters, the turbulence stress in a near-field river plume has not previously been observationally quantified. In this study, finely resolved density, velocity, and turbulence observations are combin...

متن کامل

Modeling on the Interaction of the Turbulent Diffusion Flames between a Vertical Burning Wall and a Pool Fire

Until now, very few works have been devoted to the predictions of the flame structure resulting from the combustion of a vertical burning wall adjacent to a rectangular pool fire at the floor level. This paper describes the application of a three-dimensional model to the prediction of the aerodynamic field and the thermal structure using a finite volume method for solving the fluid dynamic equa...

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

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

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2001