Estimation of the Lagrangian velocity structure function constant C0 by Large Eddy Simulation

The inertial subrange Kolmogorov constant , which determines the effective turbulent diffusion in velocity space plays, an important role in the Lagrangian modelling of pollutants. A wide range of values of the constant are found in literature, most of them determined at low Reynolds number and/or under different assumptions. Here we estimate the constant by tracking an ensemble of Lagrangian particles in a planetary boundary layer simulated with a large-eddy simulation model and analyzing the Lagrangian velocity structure function in the inertial subrange. The advantage of this technique is that it easily allows Reynolds numbers to be achieved typical of convective turbulent flows. Our estimates of is C0 = 4.3 ± 0.3 consistent with values found in literature.