Aerodynamic Force Characteristics of 3D Flapping Wings

Abstract

In this project, the aerodynamic characteristics of insect flapping wings are assessed by measuring the forces acting on them. A 3D flapping wing mechanism capable of mimicking the motion of insect flight is developed to measure forces acting on model wings flapping according to various motions. It consists of a pair of wings connected to gear boxes driven by stepper motors. The wings are immersed in a tank filled with water so that hovering characteristics can be modelled. Forces acting on the flapping wing are measured by an in-house developed force transducer consisting of strategically arranged strain gages, attached to the base of the flapping wing. The flight of a hawkmoth Manduca sexta which has a Reynolds number of approximately 7000 is investigated by mimicking its motion and wing shape. Measured mean force coefficients are in good agreement with results derived from free-flying hawkmoths but the time course of force coefficients differs from numerically predicted.