DRAGONFLY .3. LIFT AND POWER REQUIREMENTS

A mean lift coefficient quasi-steady analysis has been applied to the free flight of the dragonfly Sympetrum sanguineum and the damselfly Ca lopteryx splendens. The analysis accommodated the Saw and acceleration s involved in free flight, For any given velocity or resultant aerodyn amic force (thrust), the damselffy mean lift coefficient was higher th an that for the dragonfly because of its clap and fling, For both spec ies, the maximum mean lift coefficient <(C)over bar (L)> was higher th an the steady C-L,C-max Both species aligned their strokes planes to b e nearly normal to the thrust, a strategy that reduces the <(C)over ba r (L)> required for flight and which is different from the previously published hovering and slow dragonfly flights with stroke planes steep ly inclined to the horizontal, Owing to the relatively low costs of ac celerating the wing, the aerodynamic power required for flight represe nts the mechanical power output from the muscles, The maximum muscle m ass-specific power was estimated at 156 and 166 W kg(-1) for S, sangui neum and C, splendens, respectively, Measurements of heat production i mmediately after flight resulted in mechanical efficiency estimates of 13% and 9% for S, sanguineum and C, splendens muscles, respectively.