Maneuverability of an Ornithopter and the Effect of Gust: An Experimental Investigation

Abstract

Experimental study of the effects of gust and effects of maneuverability are performed in the rotational Reynolds number range of 5000-12000 and freestream Reynolds number of 16000. An ornithopter has been designed and built with a tail which can twist and tilt like a bird, and also can change the stroke plane of the individual flapping wing using a servo. The flying ornithopter depicts a sinusoidal variation of both lift and thrust at par with the sinusoidal gust input. The thrust and lift forces are found to be out of phase with each other in gust scenarios, one rising while the other one falling. The amplitude of the force variation decreases with the increase in the gust frequency. Addition of stroke plane changing between the two wings has a significant effect on the rolling moments, more than what can be achieved using a tail. The experiments are performed in an open jet tunnel and forces as well as moments are examined for the given change of control inputs of the tail and stroke plane of the wings.