Question

A newly proposed wind turbine consists of four blades and is designed to rotate at 70 rpm (revolutions per minute). Each blade of the wind turbine may be approximated as a flat plate, where its length is 0.6m and its width is 0.2 A) Estimate the torque needed to overcome the total drag, B) Discuss the effects of your assumptions on the accuracy of your results. State all assumptions and show all your work!

Answer 1

solutions speed of Blade N = 700pm. Blade length l=8= 0.6m speed ratio do= ro uo do = AT n n = 4 do T 415 4 t = 0.6X QUX 70 60 x 40 uo = 0.7 mis drug Fore indused by the wind Fo - Ź SAU2 2 To. = £x 1. 23 XITX0.6²x0.72 Fo 0.3408 N

by twabine T TM = Foxr 0.3408x0.6 0.2044 Nom. Tsn= CT Tm. shaft Torque CT = Се 시 Co will be 0.593 0.593 CT Tsh = 0.593 0.593 xo. 2044 -0.0303 N-m. 4 Tsh 0.0303 Nm. Assumption consichs Flat plate is mentor Blade length size is equel to the radius of Blade.

د Flow is attachtel to the plate. swept area of the plate is some as Rotor Blade corres. density the air remain constent. Actual power coeficent So= 0.593 variation og Height of Blade. if need a drag coefficent Co=1.2 = 0.3o4 X 1.2 =0.36U8N Tm 0. 204481.2= 0.24528 Nam. Tsen = 0.030381.2= 0.036 36 Nom.