Non-perturbative models of intermittency in edge turbulence

نویسنده

  • Johan Anderson
چکیده

A theory of the probability distribution function (PDF) tails of the blob density in plasma edge turbulence is provided. A simplified model of the fast convective radial transport is used. The theoretically predicted PDF tails corroborate earlier measurements of edge transport, further confirming the strongly non-Gaussian feature of edge transport. It is found that increasing the cross sectional spatial scale length (Lx and Ly) of the blob results in larger transport whereas increasing the toroidal scale length (Lz) decreases the PDF. The results imply that the PDF decreases for larger blob speed vb. [email protected] 1

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

Predicting PDF tails of flux in plasma sheath region

This letter provides the first prediction of the probability density function (PDF) of flux R in plasma sheath sheath region in magnetic fusion devices which is characterized by dynamical equations with exponential non-linearities. By using a non-perturbative statistical theory (instantons), the PDF tails of first moment are shown to be modified Gumbel distribution which represents a frequency ...

متن کامل

Simulating Cooling Injection Effect of Trailing Edge of Gas Turbine Blade on Surface Mach Number Distribution of Blade

In this research, a gas turbine blade cascade was investigated. Flow analysis around the blade was conducted using RSM and RNG.K-ε turbulence modeling and it is simulated by Fluent software. The results were considered for the cases as Mach number loss at the trailing edge of blade caused by vortexes that were generated at the end of blade. Effect of cooling flow through the trailing edge on th...

متن کامل

Intermittency in Plasma Turbulence

Intermittency in fluid turbulence can be evidentiated through the analysis of Probability Distribution Functions (PDF) for velocity fluctuations, which display a strong non–gaussian behavior at small scales. In this paper we investigate the occurrence of intermittency in plasma turbulence by studying the departure from the gaussian distribution of PDF for both velocity and magnetic fluctuations...

متن کامل

Comment on "Intermittency in tokamak edge turbulence"

Comment on " Intermittency in Tokamak Edge Turbulence " Any statistical data analysis warrants extreme caution , in the absence of which one faces the risk of drawing conclusions which may not necessarily be correct. We find that the recent analysis work [Jha et al., on the reported first measurements of intermittency in the tokamak edge turbulence is open to question on a number of counts. We ...

متن کامل

Simplifying the complexity of pipe flow.

Transitional pipe flow is modeled as a one-dimensional excitable and bistable medium. Models are presented in two variables, turbulence intensity and mean shear, that evolve according to established properties of transitional turbulence. A continuous model captures the essence of the puff-slug transition as a change from excitability to bistability. A discrete model, which additionally incorpor...

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 2009