Trajectory-guidance advantage beyond multiscale turbulence

Determine whether the navigation advantage produced by trajectory guidance in homogeneous isotropic multiscale turbulence persists in single-scale flows, and characterize how spatial inhomogeneity or coherent structures alter the relative value of local and nonlocal flow information.

Background

The paper studies vertical navigation by swimmers in homogeneous isotropic multiscale turbulence. It compares controls based on local flow measurements with controls that exploit information about high-performing trajectories, either through precalculated target trajectories or dynamically selected swarm members. The results show that nonlocal trajectory guidance can substantially outperform local strategies, although its benefit depends on the time required to intercept favorable trajectories.

The authors explicitly identify uncertainty about whether this advantage is a consequence of the multiscale nature of turbulence. They also note that spatial inhomogeneity and coherent structures could change the comparative usefulness of local versus nonlocal information, leaving the generality of the reported navigation benefit unresolved.