FORM: Power Train ~ Dragonfly

Speed:

 

Power:

 

Torque:

 

 

Ratio:

 

Loss:

 

 

 

Engine: (1)

5250

rpm

50.0 (1)

hp

48 (2)

ft-lb

Primary:

2

: 1

1

%

 

 

Intermediate:

2625

rpm

49.5

hp

97

ft-lb

Secondary:

4:1

: 1

1

%

 

 

Rotor:

655 (4)

rpm

49 (3)

hp

384 (3)

ft-lb

Total:

8.0

: 1

2

%

 

 

    1. The power required to hover is 35 hp with the VR-7 airfoil.
    2. The Hirth H 32 is 50 hp and 48 ft-lb at 5250 rpm. Ref. The Zanzottera's MZ202 engine's maximum torque is 61 at 5200 rpm. Its torque is 51 at 4500 rpm.
    3. The horsepower and torque at each rotor will be 1/2 the totals shown above.
    4. 650 RRPM and an 8 ft radius give 545 ft/sec. and therefore a quiet rotor.

 

Rotor Speed:

To have a tip speed of 550 ft/sec. (quiet) with an 8-ft disk radius the rotor speed is 657 rpm. A quiet rotor with a faster speed should be possible if modifications are made to the tip. See; 1038.html

 

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Last Revised: November 12, 2003