English

Conditional Averages and Probability Density Functions in the Passive Scalar Field

chao-dyn 2009-10-30 v4 Chaotic Dynamics

Abstract

Two conditional averages for the increment Delta(x,x+r) = T(x)-T(x+r) of the scalar field are estimated for DNS data: H(Delta)=<nabla^2 Delta(x,x+r)|Delta(x,x+r)> and G(Delta)=<|nabla Delta(x,x+r)|^2| Delta(x,x+r)>. The probability density function P(Delta) for Delta(x,x+r) is also calculated. If Delta, P(Delta), H(Delta), and G(Delta) are expressed as theta, P(theta), h(theta), and g(theta) in a dimensionless form, the data analysis has revealed interesting simple relationships between them. These relations may be helpful to construct a turbulence model.

Cite

@article{arxiv.chao-dyn/9709019,
  title  = {Conditional Averages and Probability Density Functions in the Passive Scalar Field},
  author = {Naoya Takahashi and Tsutomu Kambe and Tohru Nakano and Toshiyuki Gotoh and Kiyoshi Yamamoto},
  journal= {arXiv preprint arXiv:chao-dyn/9709019},
  year   = {2009}
}

Comments

Some amendments were made in order to clarify the text. Figures are unchanged. 9 pages, 16 figures, LaTeX209, submitted to J. Phys. Soc. Jpn

R2 v1 2026-07-22T09:55:53.430Z