Data/hora: 07/06/2024 11:04:43

Provedor de dados: | 5
País: | France
Título: | Skewness of the generalized centrifugal force divergence for a joint normal distribution of strain and vorticity components
Autores: | Hua, Bach-lien.
Data: | 1994-09
Ano: | 1994
Resumo: | This note attempts to connect the skewness of the probability distribution function (PDF) of pressure, which is commonly observed in two-dimensional turbulence, to differences in the geometry of the strain and vorticity fields. This paper illustrates analytically the respective roles of strain and vorticity in shaping the PDF of pressure, in the particular case of a joint normal distribution of velocity gradients. The latter assumption is not valid in general in direct numerical simulations (DNS) of two-dimensional turbulence but may apply to geostrophic turbulence in presence of a differential rotation (beta effect). In essence, minus the Laplacian of pressure is the difference of squared strain and vorticity, a quantity which is named the generalized centrifugal force divergence (GCFD). Square strain and vorticity distributions follow chi-square statistics with unequal numbers of degrees of freedom, when one assumes a joint normal distribution of their components. Squared strain has two degrees of freedom and squared vorticity only one, thereby causing a skewness of the PDF of GCFD and hence of pressure.
Tipo: | Text
Idioma: | Inglês

Identificador:

http://archimer.ifremer.fr/doc/00196/30691/30393.pdf

DOI:10.1063/1.868101

Editor: | Amer Inst Physics
Relação: | http://archimer.ifremer.fr/doc/00196/30691/
Formato: | application/pdf
Fonte: | Physics Of Fluids (1070-6631) (Amer Inst Physics), 1994-09 , Vol. 6 , N. 9 , P. 3200-3202
Fonte: | 1994 American Institute of Physics