Aerofoils: Lift, Drag, and Circulation - Small Wind Turbines: Analysis, Design, and Application - page 74

with J = 8kgm 2 , estimate the Lock number and compare the value with the
range of 5-10 which is common for helicopters.
10. Review the statements in Sect. 1.8 regarding the R-dependence of turbine
inertia in the light of the Lock number.
11. Explain why optimum blade element performance occurs when the lift:drag
ratio is maximised rather than, say, where lift is maximised?
12. Explain why the centre of pressure is not important for blade element analysis.

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