Probability Distribution Function of Passive Scalars in Shell Models  

作　　者：ZHANG Xiao-Qiang WANG Guang-Rui CHEN Shi-Gang 

机构地区：[1]Department of Physics, Hebei Normal University, Shijiazhuang 050016, China [2]Graduate School of the China Academy of Engineering Physics, P.O. Box 8009（28）, Beijing 100088, China [3]Center for Nonlinear Studies, Institute of Applied Physics and Computational Mathematics, Beijing 100088, China

出　　处：《Communications in Theoretical Physics》2008年第4期1033-1038,共6页理论物理通讯（英文版）

基　　金：The project supported by National Natural Science Foundation for Major Projects under Grant Nos.10336010 and 10576005

摘　　要：A shell-model version of passive scalar problem is introduced, which is inspired by the model of K. Ohkitani and M. Yakhot [K. Ohkitani and M. Yakhot, Phys. Rev. Lett. 60 （1988） 983; K. Ohkitani and M. Yakhot, Prog. Theor. Phys. 81 （1988） 329]. As in the original problem, the prescribed random velocity field is Gaussian and 5 correlated in time. Deterministic differential equations are regarded as nonlinear Langevin equation. Then, the Fokker-Planck equations of PDF for passive scalars are obtained and solved numerically. In energy input range （n 〈 5, n is the shell number.）, the probability distribution function （PDF） of passive scalars is near the Gaussian distribution. In inertial range （5≤ n ≤ 16） and dissipation range （n ≥ 17）, the probability distribution function （PDF） of passive scalars has obvious intermittence. And the scaling power of passive scalar is anomalous. The results of numerical simulations are compared with experimental measurements.

关 键 词：shell model passive scalar distribution function 

分 类 号：O411.1[理学—理论物理]