Applied Mathematics and Plasma Physics

Shiyi Chen, Brindesh Dhruva, Susan Kurien, Katepalli R. Sreenivasan and Mark Taylor, "Anomalous scaling of low-order structure functions of turbulent velocity", *J. Fluid Mech.*, vol. 533, pp. 183--182, 2005

It is now believed that the scaling exponents of moments of velocity increments are anomalous, or that the departures from Kolmogorov's (1941) self-similar scaling increase nonlinearly with the increasing order of the moment. This appears to be true whether one considers velocity increments themselves or their absolute values. However, moments of order lower than 2 of the absolute values of velocity increments have not been investigated thoroughly for anomaly. Here, we discuss the importance of the scaling of non-integer moments of order between ?? obtain them from direct numerical simulations at moderate Reynolds numbers (Taylor microscale Reynolds numbers $R_lambda le$ 450) and experimental data at high Reynolds numbers ($R_lambda approx$ 10,000). The relative difference between the measured exponents and Kolmogorov's prediction increases as the moment order decreases towards $-1$, thus showing that the anomaly that is manifest in high-order moments is present in low-order moments as well. This conclusion provides a motivation for seeking a theory of anomalous scaling as the order of the moment vanishes. Such a theory does not have to consider rare events---which may be affected by non-universal features such as shear---and so may be regarded as advantageous to consider and develop.

@article{chen-2005-anomalous-scaling,

author = {Shiyi Chen and Brindesh Dhruva and Susan Kurien and Katepalli R. Sreenivasan and Mark Taylor},

title = {Anomalous scaling of low-order structure functions of turbulent velocity},

year = {2005},

urlpdf = {http://math.lanl.gov/~skurien/papers/CDKST_loworder_jfm05.pdf},

journal = {J. Fluid Mech.},

volume = {533},

pages = {183--182}

}