Y Total velocity vector 



Y Reference speed 



(x,y,z) Cartesian coordinates fixed on propeller 



(x ,y ,z ) Cartesian coordinates in inertial reference frame 

 o o o 



X Fraction of chord, measured from leading edge 



x^ Fraction of radius, measured from axis of rotation 



Z Number of blades 



a Angle of attack . 



r Strength of discrete bound vortex for two-dimensional 



airfoil 



r Chordwise discrete vortex on the blade surface 

 — c 



r Spanwise discrete vortex on the blade surface 

 — s 



Y = Y + Y Total distributed vortex on the blade surface 



Y Chordwise distributed vortex on the blade surface 



Y Spanwise distributed vortex on the blade surface 



6 = tan (z/y) Angular coordinate in propeller-fixed coordinates 



6 = tan (z /y ) Angular coordinate in inertial reference frame 

 o o o 



6 Skew angle; circumferential displacement of blade-section 



midchord point from z=0 plane 



p Fluid density 



<t) Pitch angle of blade section nose-tail line; measured 



on cylinder of radius r 



^ = 2iTn Propeller rotational speed; radians per unit time 



w Vorticity vector in flow field 



