R_λ BEHAVIOUR OF 2ND & 4TH-ORDER MOMENTS OF VELOCITY INCREMENTS & DERIVATIVES

The R_λ behaviour of low-order (n = 2 and 4) moments of velocity increments and derivatives has been examined in anisotropic shear flows over a significant R_λ range. The inertial range scaling exponents for transverse structure functions are observed to approach those of the longitudinal structure functions. Their relative behaviour suggest that any inequality may disappear at R_λ ~ 5000, depending on the degree of global anisotropy present. The 4th-order moments of the transverse velocity derivative have approximately the same R_λ power-law exponent as the equivalent longitudinal velocity derivative moments.