Oskar
Member
- Joined
- Mar 10, 2007
- Messages
- 329
- Location
- Auckland, New Zealand
- Aircraft
- R22, MTO Sport, GyroBee, Mosquito Air
I've always been curious as to how much power is actually needed to spin rotors. Finally got the chance to measure it acurately, and was surprised by the results.
The test bed is a Mosquito helicopter where the 2 stroke engine has been replaced with an electric motor. Power is measured on the DC input, the measured power thus includes losses in the inverter, motor and drive system where applicable. Unless specified all measurements are at rated speed, motor and tail rotor speed are 2500rpm and main rotor speed is 550rpm.
Measured power was:
Motor only: 900W
Motor plus TR: 2500W
Motor plus TR plus MR (pitch set for minimum power): 9000W
To hover with AUW of 190kg requires between 16 and 17kW.
The most surprising result was that to spin the rotors while generating zero lift required 9kW, but to generate 190kg of lift required only an additional 7 to 8kW.
And here's what the setup looks like:
The test bed is a Mosquito helicopter where the 2 stroke engine has been replaced with an electric motor. Power is measured on the DC input, the measured power thus includes losses in the inverter, motor and drive system where applicable. Unless specified all measurements are at rated speed, motor and tail rotor speed are 2500rpm and main rotor speed is 550rpm.
Measured power was:
Motor only: 900W
Motor plus TR: 2500W
Motor plus TR plus MR (pitch set for minimum power): 9000W
To hover with AUW of 190kg requires between 16 and 17kW.
The most surprising result was that to spin the rotors while generating zero lift required 9kW, but to generate 190kg of lift required only an additional 7 to 8kW.
And here's what the setup looks like: