ZHURNAL EKSPERIMENTALNOI I TEORETICHESKOI FIZIKI
|
1995年
/
108卷
/
04期
关键词:
D O I:
暂无
中图分类号:
O4 [物理学];
学科分类号:
0702 ;
摘要:
Fluctuations of a passive scalar concentration in a random velocity field are considered. Statistical quantities related to the spatial derivatives of the concentration field are calculated in the presence of a nonzero mean concentration gradient and in the delta-correlation approximation. This permits an estimation of the stationary variance of the concentration, which has a logarithmic dependence on the molecular diffusion coefficient. Conditions for the applicability of the delta-correlated approximation in this problem are obtained.