UniCopter - Disk and Power Specifications - 3-blade

Name: UniCopter w/ 3-blade rotors

Item Nbr: 0847

Black is input.

Blue is calculated.

Test Conditions:

Collective Pitch: (used for Flight - Hovering w/ Blade Element Theory)

6.4

deg

Forward Speed: (used for Flight - Forward w/ Momentum Method)

150

knots

Rate of Vertical Climb: (used for Flight - Vertical w/ Momentum Method)

1000

ft/min

Weight:

Empty Weight: [EW]

730

lb.

Payoad: [Load]

420

lb.

Gross Weight: [GW = EW + Load]

1150

lb.

Rotor:

Blade:

Type of airfoil

NACA 00xx

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

0

deg.

Number of blades: [bb]

6

Radius: [R]

9.5

ft.

Chord at root: [cc] (theoretical May be modified later.)

1.667

ft.

Blade Area: [Ab]=[measured blade area; assuming area is take to mast = 55.56)

64.15

sq-ft

Aspect Ratio: [AR] = R / [the average chord of the blade, which is 11.7" = 9.7]

8.44

:1

Blade cutout ratio: (The blade root radius divided by the tip radius.)

0.2

Taper: [cct]

1.368

in/ft

Twist Type;

active

Pitch that the blade would have if extended into center of rotation.

6.4

deg.

Angle of twist (washout). Tip pitch - root pitch. i.e.negative value.

0

deg.

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

6.4

deg.

Hub(s):

Configuration:

Intermeshing

The angle of each mast off of vertical Re synchropter: [Angle]

9.00

deg.

The horizontal distance between twin rotor hubs: [Stagger]

2.50

ft.

Disk:

Disk area (1 rotor); [A1]

283.53

sq-ft

Total disk area: [AT]

330.89

sq-ft

Effective disk area: [A]

406.95

sq-ft

Rotor solidity ratio: [Sigma] = [Ab] / [AT] Will be less if based on effective area.

0.19388

%

Speed:

RPM of Rotor: [RPM Hub]

480

rpm

Tip speed: [Omega_R]

478

ft/sec

Tip mach number: [TipM]

0.43

% M1

Flight - Hovering:

Momentum Method

Disk Loading: [DL] = GW / AT

3.48

lb/ft2

Blade Loading: [BL] = GW / Ab

17.93

lb/ft2

Velocity: [V1hov] (Average of velocities through the disk.)

27.03

ft/sec.

Power; [P] (ISA i.e. Sea level, 59 deg F.)

76.59

hp.

Power Loading (for hover ONLY): [PLh] (ISA i.e. Sea level, 59 deg F.)

15.01

lb/hp

Nondimensional Coefficients;

Thrust: [CT]

0.00641

Power: [CP]

8.9E-07

CT / Sigma

0.04066

Combined Momentum and Blade Element Theory w/ Emphirical Corrections

Coefficients of:-

Thrust: [CTntl] (w/o tip loss)

0.00546

Tip loss factor: [B]

0.99

Thrust: [CT] (with tip loss)

0.00527

Profile; [CQo]

0.00017

Induced: [CQi]

0.00030

Torque: [CQ]

0.00046

Disk loading: [DL] (calculated using thrust) This is based on Effective Disk Area

2.8560

lb/ft2

Thrust Solidity: [CT/Sigma] Based on ??

0.03341

[(DL)(CT/Sigma)] Based on ??

0.09542

Measured power / Calculated power

0.96

CQ / Sigma Based on ??

0.00291

Thrust: [T] (ISA i.e. Sea level, 59 deg F. ~ drive losses not inc.)

1162.24

lb

Horsepower: [hp] (ISA i.e. Sea level, 59 deg F. ~ drive losses not inc.)

87.90

hp

Flight - Vertical:

Momentum Method

Velocity: [V1ver] (Average of velocities through the disk.)

36.62

ft/sec.

Change in power; [DeltaP]

49.41

hp.

Change in blade pitch; [DeltaTheta]

0.73

deg.

Combined Momentum and Blade Element Theory w/ Emphirical Corrections

Not done.

Flight - Forward:

Momentum Method

Velocity: [V1fwd] (Average of velocities through the disk.)

???

ft/sec.

Change in Power:

Induced: [HPind]

9.05

hp.

Parasite: [HPp] Could this be too high. It is based on F = 4 sq-ft

140.32

hp.

Profile: [HPOH]

56.39

hp.

Main (sub total): [HPm]

205.76

hp.

Combined Momentum and Blade Element Theory w/ Emphirical Corrections

Not done.