PMID- 11969951
OWN - NLM
STAT- PubMed-not-MEDLINE
DCOM- 20021023
LR  - 20190728
IS  - 1063-651X (Print)
IS  - 1063-651X (Linking)
VI  - 60
IP  - 2 Pt B
DP  - 1999 Aug
TI  - Planar isotropy of passive scalar turbulent mixing with a mean perpendicular 
      gradient.
PG  - 1691-707
AB  - A recently proposed evolution equation [Vaienti et al., Physica D 85, 405 (1994)] 
      for the probability density functions (PDF's) of turbulent passive scalar 
      increments obtained under the assumptions of fully three-dimensional homogeneity 
      and isotropy is submitted to validation using direct numerical simulation (DNS) 
      results of the mixing of a passive scalar with a nonzero mean gradient by a 
      homogeneous and isotropic turbulent velocity field. It is shown that this 
      approach leads to a quantitatively correct balance between the different terms of 
      the equation, in a plane perpendicular to the mean gradient, at small scales and 
      at large Peclet number. A weaker assumption of homogeneity and isotropy 
      restricted to the plane normal to the mean gradient is then considered to derive 
      an equation describing the evolution of the PDF's as a function of the spatial 
      scale and the scalar increments. A very good agreement between the theory and the 
      DNS data is obtained at all scales. As a particular case of the theory, we derive 
      a generalized form for the well-known Yaglom equation (the isotropic relation 
      between the second-order moments for temperature increments and the third-order 
      velocity-temperature mixed moments). This approach allows us to determine 
      quantitatively how the integral scale properties influence the properties of 
      mixing throughout the whole range of scales. In the simple configuration 
      considered here, the PDF's of the scalar increments perpendicular to the mean 
      gradient can be theoretically described once the sources of inhomogeneity and 
      anisotropy at large scales are correctly taken into account.
FAU - Danaila, L
AU  - Danaila L
AD  - IRPHE, 12 Avenue du General Leclerc, 13003 Marseille, France.
FAU - Dusek, J
AU  - Dusek J
FAU - Le Gal, P
AU  - Le Gal P
FAU - Anselmet, F
AU  - Anselmet F
FAU - Brun, C
AU  - Brun C
FAU - Pumir, A
AU  - Pumir A
LA  - eng
PT  - Journal Article
PL  - United States
TA  - Phys Rev E Stat Phys Plasmas Fluids Relat Interdiscip Topics
JT  - Physical review. E, Statistical physics, plasmas, fluids, and related 
      interdisciplinary topics
JID - 9887340
EDAT- 2002/04/24 10:00
MHDA- 2002/04/24 10:01
CRDT- 2002/04/24 10:00
PHST- 1998/10/16 00:00 [received]
PHST- 1999/03/23 00:00 [revised]
PHST- 2002/04/24 10:00 [pubmed]
PHST- 2002/04/24 10:01 [medline]
PHST- 2002/04/24 10:00 [entrez]
AID - 10.1103/physreve.60.1691 [doi]
PST - ppublish
SO  - Phys Rev E Stat Phys Plasmas Fluids Relat Interdiscip Topics. 1999 Aug;60(2 Pt 
      B):1691-707. doi: 10.1103/physreve.60.1691.