Lagrangian and Eulerian Statistics from Direct Numerical Simulations of Turbulent Channel Flow

Lagrangian and Eulerian statistics are obtained from the direct numerical simulation of a turbulent channel flow. The Reynolds number is obtained to be Re_τ=100 (based on friction velocity and channel half-height). The Lagrangian time microscales are compared to their Eulerian equivalents. It is found that the Lagrangian time microscales equal the Eulerian time microscales at the wall, but they are consistently larger than the Eulerian away from the wall. The Eulerian time scales are also found to be scaled by the propagation velocity rather than the mean velocity. The ratio of the Lagrangian to the Eulerian time microscales is found to be nearly constant away from the wall (y⁺>40).