Aerospace 2015, 2, 235-278; doi:10.3390/aerospace2020235
aerospace
ISSN 2226-4310
www.mdpi.com/journal/aerospace
Article
Ornithopter Type Flapping Wings for Autonomous
Micro Air Vehicles
Sutthiphong Srigrarom
1,
* and Woei-Leong Chan
2
1
Aerospace Systems, University of Glasgow Singapore, 500, Dover Rd., #T1A-02-24,
Singapore 139651
2
Temasek Laboratories, National University of Singapore, #09-02, 5A Engineering Drive 1,
Singapore 117411; E-Mail: tslcwl@nus.edu.sg
* Author to whom correspondence should be addressed; E-Mail: spot.srigrarom@glasgow.ac.uk;
Tel.: +65-6908-6033.
Academic Editors: David Anderson and Rafic Ajaj
Received: 2 February 2015 / Accepted: 4 May 2015 / Published: 13 May 2015
Abstract: In this paper, an ornithopter prototype that mimics the flapping motion of bird
flight is developed, and the lift and thrust generation characteristics of different wing
designs are evaluated. This project focused on the spar arrangement and material used for
the wings that could achieves improved performance. Various lift and thrust measurement
techniques are explored and evaluated. Various wings of insects and birds were evaluated
to understand how these natural flyers with flapping wings are able to produce sufficient
lift to fly. The differences in the flapping aerodynamics were also detailed. Experiments on
different wing designs and materials were conducted and a paramount wing was built for a
test flight. The first prototype has a length of 46.5 cm, wing span of 88 cm, and weighs 161 g.
A mechanism which produced a flapping motion was fabricated and designed to create
flapping flight. The flapping flight was produced by using a single motor and a flexible and
light wing structure. A force balance made of load cell was then designed to measure the
thrust and lift force of the ornithopter. Three sets of wings varying flexibility were
fabricated, therefore lift and thrust measurements were acquired from each different set of
wings. The lift will be measured in ten cycles computing the average lift and frequency in
three different speeds or frequencies (slow, medium and fast). The thrust measurement was
measure likewise but in two cycles only. Several observations were made regarding the
behavior of flexible flapping wings that should aid in the design of future flexible flapping
wing vehicles. The wings angle or phase characteristic were analyze too and studied.
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