Airfoil properties, shapes & structural dynamical features are described. Nomenclature or the classification types are presented along with the application. Common methods for analysis of the structural dynamics on a wing or blade are presented along with the possible applications.

1. PROPERTIES & TYPES OF AEROFOIL
Aero-foil
(AIRFOIL)
1 digit series
4 digit series
5 digit series
6 digit series
7 digit series
Chord Camber
Leading
edge
Trailing
edge
Thickness
Aspect
ratio
TYPES
(Major
Classification)
TERMINOLOGY
(Nomenclature)
AERODYNAMIC
PROPERTIES
# of DIGITS
FFA –W3 – xxxx (Swedish Defense Research)
e.g. Notation, W3 – 241, W3 - 245
NACA – xx-xxxx (American Aeronautics Institute)
e.g. Notation
16-123, : 1- series
2413, 0014 : 4 series
12456 : 5 series
612- 435 : 6 series
713A445 : 7 series
NREL (National Renewable Energy Labs)
e.g. S-series, Uses thick flat back airfoils for low lift
application
DELFT University, (Netherlands)
Notation, e.g. DU, 91-W1-251, 91-W2-250, 93-W-210
Risoe-DTU (Denmark)- Notation e.g. B1-18, B1-24,
Lift
Drag
Upper
surface8/7/2014 1
Force Components
Upper camber
Surface,
Lower
camber
Surface,
Mean
Camber line
Pressure
Ratio of (span/mean chord) of wing
Lower
surface
Lift & Drag are
ORTHOGONAL
8 digit series
Illustrative
figures

2. Continued …
STRUCTURAL
PROPERTIES
8/7/2014 2
Flap (Lateral)
Edge
(Vertical)
TORSION
STIFFNESS
BEND STIFFNESS
STRENGTH&STIFFNESS
Modal Analysis
First order
Second
order
First order
Second
order
First order
Second
order
Mathematically expressed as EI1
Mathematical expressed as GJ2
Description Matter
Operating Speed Range3 Application
• Sub sonic & Transonic Commercial aviation, Passenger aircraft, Helicopter, Glider,
Cargo aircrafts, Sail planes. Wind turbines
• Super sonic Defense jet aircraft, Combat aircraft (helicopter)
• Hypersonic Spacecraft, Rockets.
Other Commercial uses Power plant gas turbines (electric power)
Principal Areas of
Application
• It is a method in which mode shapes
& order determine the control &
stability behavior of the blade(wing)
system & system as whole during
design, testing & real operating
conditions.
• The harmonics of system natural
frequencies for a set of damping
conditions tell about the normal &
safe operation limits of state of the
system.
Flat
Out of plane
orientation
In plane
orientation
> 1 plane of
orientation
FLAP (Lateral) & EDGE (Vertical)
TORSION
Note: 1. I - (Moment of inertia)mass, area 2. J – Polar moment of inertia
E- Elastic modulus, G – Rigidity/Torsion modulus
The structure experiences
tension & compression
stiffness, along
orthonormal axes & often
displace or deform out of
the plane due to external
load operation
Experiences tension &
compression stiffness
along the orthonormal
axes during the operation
& displace or deform in
plane due to external
loads
Structure experiences
shear along the
orthonormal axes during
operation. They result in
deformation or deflection
of the structure or object
in contact
3. Reynolds number is used as the criteria
for differentiating the speed range
STRENGTH
(tensile, compressive, shear)
𝝈
𝒚
=
𝑴
𝑰
=
𝑬
𝑹
Bending & Torsion shear is governed by
2nd or 3rd order ordinary differential
equation
τ
𝒓
=
𝑻
𝑱
=
𝑮. θ
𝒍

3. 8/7/2014 3
Continued …
PLAN FORM & SECTIONAL VIEW OF A TYPICAL BLADE
Structural Twist angle
on airfoil
Blade spar, shear webs are shown
Wind turbine blade plan with its
material layers & root section joint
(bearing slot holes)
Aero plane wing section with its
components, flap, slat, & aileron
Blade section airfoil with nomenclature