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Fig. 8. Comparison of time-averaged and instantaneous forces and their related
dynamics. Three hypothetical flying animals of equal weight
(mg) generate identical time-averaged forces but
different instantaneous forces and flight dynamics over three stroke cycles.
Solid black line, FV-mg=0; broken
blue line,
FV-mg=sin(2
t); dotted
red line FV-mg=-sin(2
t).
Vertical velocity V(t) and trajectory Y(t)
are determined from integration with initial conditions V(0)=0 and
Y(0)=0. T, propulsive stroke duration. Figures are plotted
using generic units.