Helicopter - Disk and Power Specifications

Item Nbr:

1751

Friday, September 17, 2010

7:24:30 PM

Name: OTHER: Helicopter - Inside - Intermeshing - ELECTROTOR - SloMo

Black is input.

Blue is calculated.

Test Conditions:

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

5.4

deg

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

50

knots

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

300

ft/min

Weight:

Empty Weight: [EW]

145

lb.

Payoad: [Load]

155

lb.

Gross Weight: [GW = EW + Load]

300

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]

6

Radius: [R]

6

ft.

Chord at root: [cc]

0.58

ft.

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

20.88

sq-ft

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

12.06

:1

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

0.33

Taper: [cct]

0.33

in/ft

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

2

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

0

deg.

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

-5

deg.

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

0

deg.

Hub(s):

Configuration: Single=1, Coaxial=2, Synchropter=3, Side-by-side=4

3

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

0.00

ft.

The vertical distance between twin rotor hubs: [Gap]

6.00

ft.

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

6

deg.

The horizontal distance between twin rotor hubs: [Stagger]

1.50

ft.

Disk:

Disk area (1 rotor); [A1]

113.10

sq-ft

Total disk area: [AT]

131.05

sq-ft

Effective disk area: [A]

161.94

sq-ft

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

0.13667

%

Speed:

RPM of Rotor: [RPM Hub]

715

rpm

Tip speed: [Omega_R]

449.25

ft/sec

Tip mach number: [TipM]

0.40

% M1

Flight - Hovering:

Momentum

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

2.29

lb/ft2

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

16.75

lb/ft2

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

xx

ft/sec.

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

15.64

hp.

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

19.18

lb/hp

Nondimensional Coefficients;

Thrust:

0.00477

.

Power: [CP]

0.00000

CT / Sigma

0.04313

Combined Momentum and Blade Element Theory w/ Emphirical

Coefficients of:-

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

0.00398

Tip loss factor: [B]

0.99

Thrust: [CT] (with tip loss)

0.00387

Profile; [CQo]

0.00387

Induced: [CQi]

0.00014

Torque: [CQ]

0.00028

Disk loading: [DL] (calculated using thrust)

1.8593

lb/ft

Thrust Solidity: [CT/Sigma]

0.03503

[(DL)(CT/Sigma)]

0.06513

Measured power / Calculated power

0.96

CQ / Sigma

0.00254

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

301.10

lb

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

17.86

hp

Flight - Vertical:

Momentum

Velocity: [vv1ver] (Average of velocities through the disk.)

24.58

ft/sec.

Change in power; [DeltaP]

3.75

hp.

Change in blade pitch; [DeltaTheta]

0.23

deg.

Combined Momentum and Blade Element Theory w/ Emphirical

Not done.

Flight - Forward:

Momentum

Velocity: [vv1fwd] (Average of velocities through the disk.)

5.69

ft/sec.

Change in Power:

Induced: [HPind]

4.67

hp.

Parasite: [HPp]

1.30

hp.

Profile: [HPOH]

7.87

hp.

Main (sub total): [HPm]

13.83

hp.

Combined Momentum and Blade Element Theory w/ Emphirical

Not done.