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Wind Turbine - Rotation of the Baldes

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Old   July 11, 2013, 13:07
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sina
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Hi Glenn
I read in one of your previous post that running a serious Steady State simulation to find a rotational speed of rotor is the easiest approach. I wanna know if I run a series of steady state simulation with different rotor rpm, how I can get conclusion about the real rpm of rotor from the graph rpm vs torque?
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Old   July 13, 2013, 07:59
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It is a simple thing then to integrate through time the rpm versus torque curve to model the rotor speed versus time. The maths to do this is straight forward and should be easily done in Excel, matlab, python or whatever you like to do basic numerical work in.
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Old   July 17, 2013, 20:48
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Glenn,
thank you for your reply. you said somewhere that extrapolating to find a net zero torque in torque vs rpm curve will give us the actual rotating speed. would you please let me know the concept behind this?
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Old   July 18, 2013, 09:58
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Basic mechanics - if the rotor has zero torque then it runs at constant speed. So find the point where the fluid power equals the absorbed power and you have your steady state operating point.
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Old   July 19, 2013, 21:58
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Glenn,
Thank you for your help. I performed a simulation of axial turbine from start up based on Rigid body approach and I got almost the same result compared your suggestion (series of steady state simulation). I got almost the same rotational speed of rotor in both approach. In both case the torque got zero when the rotor get a steady rotation, I was wounder how I can calculate a power output based on the equation P=TW, now? Because torque=0.
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Old   July 20, 2013, 07:06
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If the rotor is just freewheeling around then there is no output power. But if the power/torque is being absorbed in the generator (or whatever is absorbing the power) then you just get the power straight from that.
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