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Power in shaft

  1. Sep 22, 2010 #1
    I really need help in my undergraduate thesis which focus on wind energy.

    I want to calculate the amount of Power in the wind turbine shaft, which later used to calculate the efficiency of my wind turbine.

    My wind turbine uses 3-blade household common fan as blade which have diameter of 39 cm and is conected to a shaft which have diameter of 9 mm.

    Using the available measuring device, I can therefore measure:
    - Wind Speed (m/s)
    - Rotational speed (rpm)
    - Generator Voltage (V)
    - Generator Current (A)

    Measuring attempt flaw
    I tried making a simple dynamometer with breaking system on the shaft, the brake system was connected to a newton scale. The result was full of flaw as the brake was instable causing vibration in the newton-scale. When the recorded data was calculated, with wind speed of 6.5 m/s, the Power in the shaft was 0.7 Watt, But when a loaded Generator was attached to the shaft, the generator generates 3 Watt.

    I tried to calculate by means of Inertia, but disigning and attaching flywheel needs plenty of time. Furthermore the Tachometer available calculate speed of rotation approximately at rpm with update rate of 1.5 seconds (Time flaw)

    My last option is to use generator, or by electrical means.

    All help are appreciated, if posible please reffer the resource. Lots of Thanks
    Last edited: Sep 22, 2010
  2. jcsd
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