Title: Aero II
1Aero II Lecture 29 Wing Modification III
J. E. Brandenburg EAS 3101 Spring 2007
2Agenda
- Historic Wing Innovations
- Thin airfoil approximation for finite camber
- Flaps and Slats
3Airfoil Geometry
Highly evolved systems were adopted to describe
wing geometries
4 Fly by Wire Electric Control of Airframes in
WWII
- Control accomplished by simple pressure sensors
and electro-mechanical sequencers ( delayers
and relays) - Stall warning accomplished by pressure sensors on
wings - Sequencers activated electric motors driving
screw jacks to deploy wing extensions or move
control surfaces - Success of these technologies led to modern
dynamically stable aircraft
5Electric Actuator
Based on worm drive or screw jack principle of
high force from small motor
6Unstable Airframes F-117
7WWII Wing Inovations
8Me 109
9Dauntless
10Dauntless Dive Flaps
11Control Surfaces
12Circulation
13Bernoulli Equation
14Camber Cont.
Camber is positive on front of wing and negative
on back
Camber term
15Biot-Savart Law
Effect of localized vorticity falls off as 1/r
16On Camberline
x
17Camber line is Streamline of flow
18Straight Camber Line Airfoil(symmetric)
19Coordinate Transform
20Analytic Case
21Analytic Case
?(x)
0
x
Most of lift is at front of the wing!
22Local Vorticity
23Lift Profile on Wing
Region of lowest pressure
Fast air
24Pressure Over Wing
Red marks low pressure
25For thin symmetric airfoil
CL
?
26Straight Camber Line Airfoilcambered)
27Effect of Finite Camber
28For thin cambered airfoil
29(No Transcript)
30Producing Camber
31Straight Camber Line Airfoil(symmetric)
32Straight Camber Line Airfoilwith flap depressed
33Effect of Flap Camber
34Flap Action For Small Angles
l
35Flap Designs
36Slat Designs
37Slats or Leading Edge Extension
38Effect of Slats on Camber
Zero at front of wing
39Slats and Flaperons
40Slats
41Stalls
42Slats Prevent Boundary layer Separation
43Flap and Slat Effect on Airflow
Slats do not add camber
44Leading edge extension
45Wing tips