EML4550HW9

# EML4550HW9 - The actual relationship between ( λ ) and c p...

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EML 4550/5451 Energy Conversion Systems for Sustainability Homework # 9 Due: Tuesday November 16, 2006 Topic: Wind turbine performance calculation The power produced by a wind turbine can be expressed as where: c p = coefficient of power ρ = air density A = area of wind turbine u = wind velocity The power coefficient is not a constant but depends on the ratio of the turbine’s rotating speed and the wind speed. This ratio is called the tip speed ration ( λ ) and is given by where ω T = angular velocity of wind turbine R = radius of the wind turbine
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Unformatted text preview: The actual relationship between ( λ ) and c p is dependent on the turbine design. A three-bladed (DU-93-W-210 airfoil) wind turbine with a rotor diameter of 50m using near optimum tapered and twisted blades rotates at a speed of 25 rpm. For wind speeds from 5m/s to 10m/s, calculate the power for the system. Plot c p as a function of the tip speed ratio. Also plot the power as function of wind speed. Comment on each graph. Assume an angle of attack of 4 degrees for the airfoil. P = 1 2 c p Au 3 λ = T R u...
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## This note was uploaded on 10/22/2011 for the course EML 4450 taught by Professor Greska during the Fall '06 term at FSU.

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