Scaling, Wing Geometry and Kinematics of Bird Flight...Scaling, Wing Geometry and Kinematics of Bird...
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Scaling, Wing Geometry and Kinematics of Bird Flight Tianshu Liu Department of Mechanical and Aerospace Engineering Western Michigan University Kalamazoo, MI 49008
Transcript of Scaling, Wing Geometry and Kinematics of Bird Flight...Scaling, Wing Geometry and Kinematics of Bird...
Scaling, Wing Geometry and Kinematics
of Bird Flight
Tianshu Liu
Department of Mechanical and Aerospace Engineering
Western Michigan University
Kalamazoo, MI 49008
Human’s Dream of Flight:
Fly like Birds
Wright Brothers’ Flyer
A Good Idea of George Cayley:
Separating Lift and Propulsion
Modern Jets
Recent Interests on Flapping Flight:
Micro Air Vehicles
Scaling Questions
• Similarity and Difference in Scaling
of Geometry, Velocity and Power ?
• Aerodynamic Implications of Scaling ?
Two Long-Standing Problems
• Relative Efficiency of Flapping Flight against
Fixed-Wing Flight
• Maximum Weight for Feasible and Sustainable
Flapping Flight
Scaling
3/1W~S/W,L,b
Wing Span, Overall Length, Wing Loading:
3/2W~S
Wing Area:
6/1W~U
Velocity:
6/7W~P
Power:
Maximum Take-Off Weight vs. Empty Weight
W786.1WMTO
Upper Bound of Weight vs. Mean Weight for Birds
Wing Span vs. Weight
Wing Area vs. Weight
Overall Body Length vs. Weight
Maximum Body Diameter vs. Weight
Wing Loading vs. Weight
Cruising Velocity vs. Weight
Birds:
Heavier!
More lift?
Weight vs. Reynolds Number
Cruise Power vs. Weight
Engine and Muscle Power Available
Engine Power Available vs. Engine Weight
Engine Weight vs. Total Weight
Specific Power of Aero-Engine and Muscles
Scaling Laws
85.0prop Scaling Laws:
Unsteady Lifting-Line: 75.0prop
Optimum Wake Model: 85.0prop
Derived Results from the Scaling Laws
Bird Muscle Power Available:
Cruise Power Required:
Flying Bird Weight Limit:
Deduction: Flying Bird Weight Limit
6/7
bird,mr W23.1P
9675.0
muscle,A W4.3P
kg4.108.16
Mute Swan: < 15 kg
Further Deduction: Pterosauers
W =126-292 N
Deduction:
Sustainable Flapping Flight Take-off from ground???
More Deduction: Archaeopteryx
W= 2.5 N
Muscle Power < 50% Deduction:
Sustainable Flapping Flight
Take-off from ground???
• Birds are geometrically similar to aircraft.
Conclusions Based on Comparative Scaling
• Birds and aircraft have comparable flight efficiency
in cruising flight.
No Comparison:
Agility and Maneuverability of Birds
Avian Wing Geometry and Kinematics
3D Laser Scanner
on FARO Arm Data Cloud of Seagull
Wing Surface
Geometry Data Processing
3
1n
1nn
max)c()c()12(S)1(
c
z
c
z
The camber line:
The thickness distribution:
4
1n
1nn
max)t()t()(A
c
z
c
z
The wing planform:
)(F)(F2/b
c
2/b
ccorrOK
0
Seagull Wing Geometry
The camber line and thickness
distribution
Seagull Wing Planform Seagull Wing Chord
Distribution
Reconstructed Seagull Wing Surface
Merganser Teal
Owl
Merganser, Teal and Owl Wings
Owl
Teal Merganser
Avian Airfoil Comparison
Avian Wing Kinematics (Crane, Seagull & Goose)
2
4/12
4/11
4/1
2/b
y)t(A
2/b
y)t(A
2/b
z
The front-projected 1/4-chord line:
2
1n
n1n1101 )tncos(B)tnsin(CC)t(A ,
2
1n
n2n2202 )tncos(B)tnsin(CC)t(A ,
2
1n
bnbn0b )tncos(B)tnsin(CC)2/bmax(
2/)t(b
.
Two-Jointed Arm Model
3D View
Projected Views
X-Ray
Reconstruction of the Flapping Seagull Wing
0t 4/
2/
4/3
f =1.0 Hz
f =2.0 Hz
Aerodynamics of Flapping Flying Seagull
Cheolheui Han (2009)
Aerodynamics of Flapping Flying Bat
Wang et al. (2010)
Aerodynamics of Microraptor
-- The Origin of Bird Flight
Xu et al. (2000)
