Traccianti lagrangiani in flussi turbolenti di parete

Lagrangian tracers are employed in a channel flow to study the drag reduction obtained by lateral sinusoidal oscillations of the walls. Tracers are injected in the turbulent boundary layer and trajectories are computed by the open-source software Paraview while the velocity field is acquired by direct numerical simulation of the Navier Stokes equation for an incompressible flow. The study considers an additional flow, analogous to the previous one, in which the walls are kept still. These two flows are studied by analyzing the tracer's motion in the turbulent boundary layer. Results show significant differences on the tracer's spreading quantified by processing the particle density as a function of space and time.