Aerodynamic research of
Flapping MAV
Background
Flapping Micro Air Vehicles (FMAVs) as the most intriguing
type of MAVs family have obtained a great interest due to
their outstanding efficiency and maneuverability. The
flapping wings can generate both lift and thrust for an
available flight. With onboard cameras and sensitive
devices, these radio-controlled FMAVs are capable to
implement tasks of surveillance, exploration and rescue.
The inherent low Reynolds and unsteady aerodynamics
caused by flapping motion results an uncomfortable
aerodynamic behavior, conventional aerodynamic theories
and analysis methods are no longer applicable on FMAVs.
Ultimately, it is always essential to offer the designers and
engineers a clear picture about the overall aerodynamic
knowledge and useful tool to organize the FMAVs for
specific mission objective and flight envelop.
This sub-project is now embedded in the STW project:
“Insect Flight Inspired New Generation of Flapping -Wing
Micro- Aircraft”
PhD Candidate: S. Deng
Department: AWEP
Section: Aerodynamics
Supervisor: B. van Oudheusden
Co-Supervisors: B. Remes
R. Ruijsink
Promoter: H.Bijl
Start date: 10-1-2011
Funding: STW
Gallery
3D unsteady Navier-Stoke equations in ALE scheme with
dual-time preconditioning technique for all-speed flow as:



QdV   WdV   ( F (W )  vgW )dS   Fv dS

 V
t V
S
S
Different Configurations of Ornithopters
Validation on N-S Solver we developed
Progress and Objectives
Aerospace Engineering
Fast mesh deformation on Delaunay Graph Mapping
Overset Grid Schematics
Delfly Micro ProtoType
Research Methodology
Experimental Methods
• Free flight test will be conducted on the prototype Delfly
Micro to obtain the flight performance such as control
ability, stability and Duration.
Wake Topology of Plunge Airfoil
An efficient and accuracy N-S solver coupled of the ability
of dynamic mesh strategies has been developed. For the
inherent unsteady aerodynamics of flapping motion, two
optional dynamic mesh methods are employed. Overset
grid is responsible for large scale movement to guarantee
the mesh quantity, while fast grid deformation based on
Delaunay graph mapping will take care of small
deformation, such as flexibility and Fluid-Structure
interaction due to its notable computational efficiency.
Such numerical tool can provide a reliable prediction and
optimization of flapping motion by parametric test.
Experimental, computational and analytical methods are
used in combination to further describe and investigate the
characteristics. This will reveal to what extent beneficial
unsteady aero-elastic phenomena are present in the
current designs and how they may be further improved.
Further campaign will be conducted on the Wind Tunnel
measurement on the Delfly Micro prototype which can
collect sufficient data for next optimization and
minimization. Also flow visualization techniques PIV
(Particle Image Processing) will be performed on Delfly
Micro to provide a detail insight into the flow behavior
around the flapping wing. Results of the experiments will
provide feedback and input for further optimization.
Alternatively, the data from experiments can provide
specific validation data for testing the CFD method.
• Wind-Tunnel Experiments can provide a quantitative
measurement for Delfly ornithopter. Knowledge based
on wind tunnel results will guide for further
optimizations. Flow visualization can be obtained by
PIV(Particle Image Velocimetry) technique.
Numerical Methods
• Quasi-Steady Model based on blade element theory for
roughly estimation of the forces on a flapping wing.
Certain PhD project will be especially dedicated to the
further development and miniaturization of the Delfly MAV
concept, along the lines of the existing Delfly Micro design.
With an ambitious destination that establishing an overall
FMAV design concept and its system integration.
• Complete Navier- Stroke simulations will give a detailed
flow performance and topology on flapping motion
Movement during flapping motion.
• Dynamic mesh strategies are capable to realize motion
of objects with temporal unsteady aerodynamics.
During the past period, a great deal of progress has been
accomplished on the research on Flapping MAVs.
Fundamental theoretical knowledge and previous research
have been systematically referred. Meanwhile, staff from
MAVLab provide a lot assistance on the fabrication of micro
parts, which now results in other prototypes for both free
flight and wind tunnel measurements.
Vorticity Contour Behind Flexible Airfoil
Publications
-S.Deng, B.W.van Oudheusden, T.Xiao, H.Bijl: “A Computational Study on the Aerodynamic Influence of a Propeller on an MAV by Unstructured Overset Grid Technology and Low Mach
Number Preconditioning”. The Open Aerospace Engineering Journal, vol 5 (2012), 11-21.
-S.Deng, T.Xiao, W.B.Tay, B.W. van Oudheusden, H.Bijl: “Numerical Investigation of Flexible Flapping Wing Propulsion at Low-Reynolds Numbers”. International Micro Air Vehicle Conference
and Flight Competition (IMAV 2012), 3-6 July 2012, Braunschweig, Germany.