DOI: 10.1615/TSFP2
AN EMPIRICAL MODEL TO ACCOUNT FOR DIFFERENCES BETWEEN LONGITUDINAL AND TRANSVERSE STRUCTURE FUNCTIONS DUE TO ANISOTROPY
SINOPSIS
In this paper the difference between scaling exponents derived from longitudinal and transverse structure functions is examined. Several flow fields are considered to relate such a difference to the Reynolds number (which reflects the small-scale anisotropy) and to the ratio between longitudinal and transverse velocity fluctuations (which depends on the large scale anisotropy). The experimental results confirm that the difference between longitudinal and transverse scaling exponents changes as a result of the previous anisotropics. It decreases with the Reynolds number and increases as the ratio of the rms values of the velocity fluctuations in the longitudinal and mean shear flow directions. The experimental results are in reasonable agreement with predictions from an empirical model based on the small and large scale asymptotes of structure finctions.