Phase II Final Report - NASA's Institute for Advanced Concepts

Planetary Exploration Using Biomimetics
An Entomopter for Flight on Mars
investigated in previous works. The formation of the LEV and its downstream convection have
been investigated for α and Reynolds variations over a wide range. Results from the cases considered
in this report indicate that by carefully choosing the Reynolds number regime and the
wing kinematics during the wingbeat cycle, lift can be increased to meet the demands of a flapping-wing
MAV design for operating in the Mars environment.
3.3.1.8 Future
CFD Work
Future work on the
CFD portion of
Entomopter analysis
could focus on
improving the current
model and
comparing these
results to experiments.
Understanding
low Reynolds
number, high angleof-attack
aerodynamics
by conducting
a coordinated
CFD/experimental
effort should be an
important objective
of future work.
Improving the
model would
Figure 3-102: Wind Tunnel Flow Visualization Image of Flow Over a
Thin Wing at High α. Flow is from Bottom to Top and Light Sheet
Illumination from Left to Right. Trailing Edge Vortex is Clearly
Visible.
include a more detailed wing shape with thickness, wing bending, and more accurate flow conditions.
The parameter space could be expanded to include larger ranges of flight speeds, flapping
angles, flapping rates, and mass flow ejection rates. Experimental work would include PIV
wind tunnel analysis of a flapping and/or pitching wing with CFD simulation results.
3.3.2 Angle of Attack Analysis
A key factor calculating the wing lift for the Entomopter is the angle of attack of the atmosphere
relative to the wing. Because of the unsteady environment in which the wings operate, this angle
of attack is not constant and will vary throughout each wing beat. The angle of attack is also
affected by wing geometry and operating conditions, such as wing-beat frequency, wing length,
maximum wing-flap angle, and forward velocity of the vehicle.
For this analysis an operating point was chosen based on the power-required analysis. The wing
section length was chosen to be 0.6 m and the relative lifting capacity was chosen to be 1.5 kg
(This is the amount of mass that can be lifted by the wings minus the wing mass). The wing
velocity through one flap cycle is shown in Figure 3-103.
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Phase II Final Report