On the Lundgren-Townsend model of turbulent fine scales
نویسندگان
چکیده
The strained-spiral vortex model of turbulent fines scales given by Lundgren [Phys. Fluids 25, 2193 ( 1982)] is used to calculate vorticity and velocity-derivative moments for homogeneous isotropic turbulence. A specific form of the relaxing spiral vortex is proposed modeled by a rolling-up vortex layer embedded in a background containing opposite signed vorticity and with zero total circulation at infinity. The numerical values of two dimensionless groups are fixed in order to give a Kolmogorov constant and skewness which are within the range of experiment. This gives the result that the ratio of the ensemble average hyperskewness S’++ t = (au/&c) QJ+ ‘/[(&/ax) 2](2P+ 1)‘2 to the hyperflatness
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