Cord

Middle line

http://www.pagendarm.de/trapp/programming/java/profiles/NACA4.html

a

Angle of attack

Velocity

c

Lift

FL

Drag

FD

Pressure distribution around an airfoil

http://www.desktopaero.com/appliedaero/

0

-

+

DH

Pressure along the upper surface

Pressure along the lower surface

Lift

Lift

FL

Lift coefficient
CL

FL

Drag

Drag

FD

Drag coefficient
CD

FD

Blade profile data

Angle of attack

Average relative

velocity

d

v

Angle of attack

Peripheral velocity =

U

w

U

C

Wind velocity = C

Relative velocity = V

V

U

V

C

FL

FD

Torque

Trust

U

V

C

Torque

Trust

U

V

C

Torque

Trust

Torque

Trust

Fthrust

Mthrust

C

Fthrust

Mtorque

w

R

U

w

=

Depth

h

Cordelengt

C

2

c

F

L

2

L

r

=

Depth

h

Cordelengt

C

2

c

F

L

2

L

r

=

Depth

h

Cordelengt

C

2

c

F

D

2

D

r

=

Depth

h

Cordelengt

C

2

c

F

D

2

D

r

=

L

D

C

C