首页   按字顺浏览 期刊浏览 卷期浏览 Statistics of an advected passive scalar
Statistics of an advected passive scalar

 

作者: Yoshifumi Kimura,   Robert H. Kraichnan,  

 

期刊: Physics of Fluids A  (AIP Available online 1993)
卷期: Volume 5, issue 9  

页码: 2264-2277

 

ISSN:0899-8213

 

年代: 1993

 

DOI:10.1063/1.858530

 

出版商: AIP

 

数据来源: AIP

 

摘要:

An elementary argument shows that non‐Gaussian fluctuations in the temperature at a point in space are induced by random advection of a passive temperature field that has a nonlinear mean gradient, whether or not there is molecular diffusion. This is corroborated by exact analysis for the nondiffusive case and by direct numerical simulation for diffusive cases. Eulerian mapping closure gives results close to the simulation data. Non‐Gaussian fluctuations of temperature at a point also are induced by a more subtle mechanism that requires both advection and molecular diffusion and is effective even when the statistics are strictly homogeneous. It operates through selectively strong dissipation of regions where intense temperature gradients have been induced by advective straining. This phenomenon is demonstrated by simulations and explored by means of an idealized analytical model.

 

点击下载:  PDF (1561KB)



返 回