Helicopter Disk and Power Specifications
Item Nbr:119Friday, March 17, 20003:06:27 PM
Name:Gen H-4 Rhyme BDH strap-onText in black is input. Text in blue is calculated.
Test Conditions:

Collective pitch: [Theta_o] (used for Flight - Hovering w/ Blade Element Theory)4.68
deg

Forward Speed: [Vfwd] (used for Flight - Forward w/ Momentum Method)55
knots

Rate of Climb: [Vver] (used for Flight - Vertical w/ Momentum Method)500
ft/min
Weight:

Empty Weight: [EW]140
lb.

Load240
lb.

Gross Weight: [GW = EW + Load]380
lb.
Rotor:

Blade:

Type of airfoil8-H-12

Angle of attack for zero lift [AlphaL0] (0 for 0012. >0 for cambered airfoil.)-1.4
deg.

Number of blades: [bb]4

Radius: [R]6.5417
ft.

Chord: [cc]0.25
in.

Blade Area: [Ab]=[bb*cc*R]6.54
sq-ft

Aspect Ratio: [R / cc]26.17
:1

Blade cutout ratio: [xo] (The blade root radius divided by the tip radius.)0.7

Taper (not used at present) [cct]0.6

Twist Type; 1 - none; 2 - linear; 3 - ideal.1

Pitch that the blade would have if extended into center of rotation. [Theta_o]0
deg.

Angle of twist (washout). Tip pitch - root pitch. i.e.negative value. [Theta1]0
deg.

Pitch at the blade tip: [Theta_t] (for ideal only)0
deg.

Hub(s):

Rotor Configuration: Single=1, Coaxial=2, Synchropter=3, Side-by-side=42

Center to center distance between twin rotor shafts: [Ctr-Ctr]1.00
ft.

The vertical distance between twin rotor hubs: [Gap]0.75
ft.

The angle of each mast off of vertical Used with synchropter: [Angle]0.00
deg.

The horizontal distance between twin rotor hubs: [Stagger]0.00
ft.

Disk:

Disk area (1 rotor); [A1]134.44
sq-ft

Total disk area: [AT]134.44
sq-ft

Effective disk area: [A]191.71
sq-ft

Disk loading: [DL] (calculated using gross weight)1.98
lb/ft2

Blade Loading: [BL]58.09
lb/ft2

Rotor solidity ratio: [Sigma]0.03412
%

Speed:

RPM of Rotor: [RPM Hub]850
rpm

Tip speed: [Omega_R]582.29
ft/sec

Tip mach number: [TipM]0.52
% M1
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