Intermittency feature of shear stress fluctuation in high-Reynolds-number turbulence

Instantaneous shear stress fluctuations are considered for high-Reynolds-number (up to R(lambda)approximate to 10(4)) turbulent flow field using the concept of maximum norm. The maximum norm is defined as the largest change within a box of a given size. We have applied this technique to a variety of flow fields and a wide range of Reynolds numbers. Results indicated that the maximum norm has a power law behavior with the size of the box. This novel approach is applied to the dissipation field and the scaling behavior is found to agree very well with that obtained using conventional methods. Thus, we obtain the intermittency exponents for both shear stress and the dissipation rate. We find that the shear stress fluctuation is less intermittent than the dissipation field. Implications of these results are discussed briefly. (C) 1999 American Institute of Physics. [S1070-6631(99)03310-3].