The dissipation tensor εij in wall turbulence

The paper investigates the dissipation tensor epsilon(ij) in wall turbulence. Available direct numerical simulation (DNS) data are examined to illustrate the differences in the anisotropy of the dissipation tensor epsilon(ij) with respect to the anisotropy of the Reynolds stresses r(ij). The budgets of the transport equations of the dissipation tensor epsilon(ij) are studied using novel DNS data of low Reynolds number turbulent plane channel flow with spatial resolution sufficiently fine to accurately determine the correlations of products of two-derivatives of fluctuating velocities u'(i) and pressure p' which appear in various terms. Finally, the influence of the Reynolds number on the diagonal components of epsilon(ij) (epsilon(xx), epsilon(yy), epsilon(zz)) and on the various terms in their transport equations is studied using available DNS data of Vreman and Kuerten (Phys. Fluids, vol. 26, 2014b, 085103).