2.10 Fins in series can interact hydrodynamically
A glance at Fig. 1 shows that the dorsal and anal
fins are located just in front of the tail, which thus could
move through flow that has been significantly altered
by the action of these forward median fins. Drucker
and Lauder[37,62] and Tytell[61] showed experimentally
that there is a substantial vortex wake shed by the dorsal and anal fins, and quantified wake flow incident to
the tail (see Fig. 8). A key result of these studies is
the demonstration that the tail does not move through
undisturbed free-stream flow.