JavaProp Quick Reference Card

character description unit
lowercase characters
a speed of sound m/s
a axial induction factor (axial acceleration = a*v) -
a' rotational induction factor (swirl = a'*v) -
c chord length m
n rotations per second (RPM/60) 1/s
r radius station of propeller (r = 0...R) m
v axial velocity (air speed) m/s
uppercase characters
B number of blades -
D drag force N
D diameter of propeller m
D* diameter of spinner m
H pitch of propeller m
L lift force N
P power to drive propeller W
R radius of propeller (D/2) m
S reference area (for wings and airfoils) m2
T thrust delivered by propeller N
greek characters
a (alfa) angle of attack
b (beta) blade angle
d (delta) swirl angle at propeller
(delta_ff) swirl angle far behind propeller (far field)
h (eta) efficiency of propeller                  frm_eta.gif (1043 Byte) - or %
h* (eta*) max. possible efficiency for same thrust - or %
rho  (rho) density of fluid kg/m3
v   (nue) kinematic viscosity of fluid m2/s
W (Omega) rotations in radians per second (RPM*2*pi/60) 1/s
character description unit
derived values and coefficients
Cl lift coefficient                   Cl = L/(rho/2*v^2*S) -
Cd drag coefficient                   Cd = D/(rho/2*v^2*S) -
L/D glide ratio (L/D = Cl/Cd) -
Re Reynolds number -
Ma Mach number -
advance ratio (also called J)  frm_vnd.gif (1042 Byte) -
advance ratio (axial velocity to tip velocity) -
Ct thrust coefficient             -
power coefficient           CP = P / (rho*n^3*D^5) -
elemental thrust coefficient -
elemental power coefficient -
in-plane shear force coefficient           -
out-of-plane shear force coefficient           -
in-plane bending moment coefficient           -
out-of-plane bending moment coefficient           -

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Last modification of this page: 21.05.18

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