TY - JOUR
T1 - Anisotropy of small-scale scalar turbulence
AU - Kurien, Susan
AU - Aivalis, Konstantinos G.
AU - Sreenivasan, Katepalli R.
PY - 2001/12/10
Y1 - 2001/12/10
N2 - The anisotropy of small-scale temperature fluctuations in shear flows is analysed by making measurements in high-Reynolds-number atmospheric surface layers. A spherical harmonics representation of the moments of scalar increments is proposed, such that the isotropic part corresponds to the index j = 0 and increasing degrees of anisotropy correspond to increasing j. The parity and angular dependence of the odd moments of the scalar increments show that the moments cannot contain any isotropic part (j = 0), but can be satisfactorily represented by the lowest-order anisotropic term corresponding to j = 1. Thus, the skewnesses of scalar increments (and derivatives) are inherently anisotropic quantities, and are not suitable indicators of the tendency towards isotropy.
AB - The anisotropy of small-scale temperature fluctuations in shear flows is analysed by making measurements in high-Reynolds-number atmospheric surface layers. A spherical harmonics representation of the moments of scalar increments is proposed, such that the isotropic part corresponds to the index j = 0 and increasing degrees of anisotropy correspond to increasing j. The parity and angular dependence of the odd moments of the scalar increments show that the moments cannot contain any isotropic part (j = 0), but can be satisfactorily represented by the lowest-order anisotropic term corresponding to j = 1. Thus, the skewnesses of scalar increments (and derivatives) are inherently anisotropic quantities, and are not suitable indicators of the tendency towards isotropy.
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U2 - 10.1017/s0022112001006176
DO - 10.1017/s0022112001006176
M3 - Article
AN - SCOPUS:0035842091
SN - 0022-1120
VL - 448
SP - 279
EP - 288
JO - Journal of Fluid Mechanics
JF - Journal of Fluid Mechanics
ER -