ANGLES

The angle "c" is used for calculating the angle "b".

(Formula 5):

Cot c = (1.5 x r x Tip Speed Ratio)/R

 

"r" is the radius (from the hub) of computation, while "R" is the the

total radius of the blade.

 

Ian cummings:

Cot c tip = (1.5 x 0.82 x 7)/0.82 = 10.5

C = 5.5 degrees

 

Compute "c" for different values of different "r" with small intervals

at the outer third of the blade.

 

The angle "b" is used for the construction of the blade in the workshop

 

(Formula 6):

b = c - a

 

The angle "a" is the angle of attack, which is constant for all

values of "r". The angle of attack is depends on Cl and

determined from the "a"/Cl-curve.

 

Ian cummings:

The "a"/Cl-curve give an angle of attack of 6 degrees

b-tip = 5.5 - 6 = - 0.5 degrees

 

Compute "b" for different values of "r" with small intervals at the outer third of the blade