UniCopter - Disk and Power Specifications - 4-blade

Name: UniCopter w/ 4-blade rotors

Item Nbr: 0862

Black is input.

Blue is calculated.

Test Conditions:

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

7.5

deg

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

130

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

VR-7

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

-1.4

deg.

Number of blades: [bb]

8

Radius: [R]

8.33

ft.

Chord at root: [cc]

1.25

ft.

Blade Area: [Ab]=[bb*cc*R]

54.4

sq-ft

Aspect Ratio: [AR] = R / (cc - (R * (cct / 12) / 2))

10.2

:1

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

0.3214

Taper: [cct] inches / foot

1.25

Twist Type;

linear

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

7.5

deg.

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

-7

deg.

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

1.5

deg.

Hub(s):

Configuration:

Intermeshing

The vertical distance between twin rotor hubs: [Gap]

0.0

ft.

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]

218

sq-ft

Total disk area: [AT]

259

sq-ft

Effective disk area: [A]

315

sq-ft

Rotor solidity ratio: [Sigma] = [Ab] / [A]

0.17

%

Speed - Hover:

RPM of Rotor: [RPM Hub]

550? ~ 533

rpm

Tip speed: [Omega_R]

547? ~ 465

ft/sec

Tip mach number: [TipM]

0.49? ~ 0.42

% M1

Speed - Cruise:

RPM of Rotor: [RPM Hub]

275?

rpm

Tip speed: [Omega_R]

274?

ft/sec

Tip mach number: [TipM]

0.0245?

% M1

Flight - Hovering:

Momentum Method

Disk Loading: [DL] (calculated using gross weight)

3.65

lb/ft2

Blade Loading: [BL] (calculated using gross weight)

21.1

lb/ft2

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

30.5

ft/sec.

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

87

hp.

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

13.2

lb/hp

Nondimensional Coefficients;

Thrust: [CT]

0.0086

.

Power: [CP]

1.4E-07

CT / Sigma

0.045

Combined Momentum and Blade Element Theory w/ Emphirical Corrections

Coefficients of:-

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

0.007

Tip loss factor: [B]

0.99

Thrust: [CT] (with tip loss)

0.00714

Profile; [CQo]

0.00017

Induced: [CQi]

0.00031

Torque: [CQ]

0.00041

Disk loading: [DL] (calculated using thrust)

3.669

lb/ft2

Thrust Solidity: [CT/Sigma]

0.04134

[(DL)(CT/Sigma)]

0.15167

Measured power / Calculated power

0.98

CQ / Sigma

0.00277

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

1155.74

lb

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

65.4

hp

Flight - Vertical:

Momentum Method

Velocity: [V1ver] (Average of velocities through the disk.) 37.06

40 ft/sec.

Change in power; [DeltaP]

49.37

hp.

Change in blade pitch; [DeltaTheta]

0.75

deg.

Combined Momentum and Blade Element Theory w/ Emphirical Corrections

Not done.

Flight - Forward:

Momentum Method

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

#Error ft/sec.

Power:

Induced: [HPind]

10.80

hp.

Parasite: [HPp]

91.34

hp.

Profile: [HPOH]

46.56

hp.

Main (sub total): [HPm]

148.70

hp.

Combined Momentum and Blade Element Theory w/ Emphirical Corrections

Not done.