Helicopter Specifications

Item Nbr:

97

Monday, March 06, 2000

2:13:26 PM

Name:

Ultrasport 254

Text in black is input.

Text in blue is calculated.

Test Conditions:

Collective pitch: [Theta_o] (used in hover calculation w/ blade element theory)

3

deg

Forward Speed: [Vfwd] (used in momentum theory)

55

knots

Rate of Climb: [Vver] (used in momentum theory)

500

ft/min

Weight:

Empty Weight: [EW]

252

lb.

Load

273

lb.

Gross Weight: [GW = EW + Load]

525

lb.

Rotor:

Blade:

Type of airfoil

VR-7

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

-1.4

deg.

Number of blades: [bb]

2

Radius: [R]

10.5

ft.

Chord: [cc]

0.5583

ft.

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

11.72

sq-ft

Aspect Ratio: [R / cc]

18.81

:1

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

0.1

Taper (not used at present) [cct]

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=4

1

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

0.00

ft.

The vertical distance between twin rotor hubs: [Gap]

0.00

ft.

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

deg.

The horizontal distance between twin rotor hubs: [Stagger]

0.00

ft.

Coning Angle [a0]

3.00

deg.

Disk:

Disk area (1 rotor); [A1]

346.36

sq-ft

Total disk area: [AT]

346.36

sq-ft

Effective disk area: [A]

346.36

sq-ft

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

1.52

lb/ft2

Blade Loading: [BL]

44.78

lb/ft2

Rotor solidity ratio: [Sigma]

0.03385

%

Engine and Power Train:

Engine Nbr: (datebase identifier)

184

Make:

Hirth

Model:

2703

Engine Count

1

Ratio

11.79

: 1

Loss

4

%

RPM Hub: (Engine operation rpm divided by Ratio.)

500

rpm

Flight - Hovering:

Momentum Method

Disk Loading: [DL]

1.52

lb/ft2

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

17.85

ft/sec.

Power; [P] (see *) (Figure of Merit set to 0.65)

26.33

hp.

Power Loading: [PL] (for hover ONLY) (see *)

19.94

lb/hp

Nondimensional Coefficients;

Thrust: [CT]

0.00211

Power: [CP]

0.00000

CT / Sigma

0.06230

Combined Momentum and Blade Element Theory w/ Emphirical Corrections

Coefficients of:-

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

0.00232

Tip loss factor: [B]

0.97

Thrust: [CT] (with tip loss)

0.00211

Profile; [CQo]

0.00211

Induced: [CQi]

0.00004

Torque: [CQ]

0.00009

Power: [CP]

0.00000

ROI CQi / Thrust CQi

Disk loading: [DL] (calculated using thrust)

1.5169

lb/ft2

Thrust Solidity: [CT/Sigma]

0.06235

[(DL)(CT/Sigma)]

Measured power / Calculated power

0.96

CQ / Sigma

0.00000

Thrust: [T] (see *)

525.39

lb

Horsepower: [hp] (see *)

22.91

hp

* Calculated values are at International Standard Atmosphere (i.e. Sea level & 59 deg F.).

Flight - Vertical:

Momentum Method

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

22.50

ft/sec.

Change in power; [DeltaP]

12.39

hp.

Change in blade pitch; [DeltaTheta]

0.03

deg

Combined Momentum and Blade Element Theory w/ Emphirical Corrections

Not done.

Flight - Forward:

Momentum Method

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

5.76

ft/sec.

Change in Power:

Induced: [HPind]

5.53

hp.

Parasite: [HPp]

0.00

hp.

Profile: [HPOH]

8.79

hp.

Main (sub total): [HPm]

14.32

hp.

Combined Momentum and Blade Element Theory w/ Emphirical Corrections

Not done.

.

.