Figure 5.

(a) Computational procedures to explore the effects of wake interception. We digitally removed the wake at time 14 ms, then iterated the preliminary solution until it converged with N–S equations, then imported it into the counterfactual force-effect and trajectory-effect simulations as artificial initial condition. In the ‘force-effect’ simulation, the fish's trajectory is prescribed to be the same as in the simulation with wake (factual simulation); in the ‘trajectory-effect’ simulation, the fish's trajectory reflects the forces acting on the fish. (b) Wake removal zone.