Figure 4.

(a) Propulsive efficiency and mean thrust coefficient as a function of the Strouhal number for cases with $\psi ={90}^{\circ }$ and ${\theta }_0={15}^{\circ }$. Lines with the same style share the same $h_0$. (b) Spatial orbits of $\alpha$ and $T\dot{\alpha }$. Lines with the same style share the same $St$.