Use blade-element theory to compute the correction to the axial-momentum theory expression for the power (30.7)

To first order in c_d/c_l for an optimized blade. First, recompute f _T and f _N including the drag force and show that the right-hand side of eq. (30.15)

is modified by a factor (1 + (c_d/c_l) tan φ)⁻¹. Then compute the power as in Problem 30.7, keeping only terms to first order in cd/cl . How big is this correction for a turbine with c_d/c_l = 0.01, λ = 10, and a = 1/3?

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v2 = (1 – a)v1, v4 = (1 – 2a)v1 A1 = (1 – a)AT, Ат 1- 2a Ад %3D %3D P = Pou}A7 4a(1 – ay² . %3D K 8πα sin o Àc, B