A threebladed wind turbine has a rotor diameter of 381m The

A three-bladed wind turbine has a rotor diameter of 38.1m. The blade chord is constant and equal to 1.0 m. Each blade has a non-rotating natural frequency of 1.67 Hz In operation rotating at 50 rpm. each blade has a natural frequency of 1.92 Hz. The pitch angle of the blade is 1.8 degrees. (The hub is sufficiently small that it can be ignored.) The turbine is operating in a wind of 8 m/s. The airfoil lift curve slope is equal to 2pi. Air density is 1.225 kg/m^3 If the blade has a mass of 898 kg. what (a) hinge-spring stiffness, (b) moment of inertia and (c) offset would be used to model the blade dynamics with the hinge-spring blade model\'\'

Solution

Proposals for a parking ramp having been defeated, we plan to build a parking lot in the downtown urban renewal section. The cost of land is 200W + 100D, where W is the width along the street and D the depth of the lot in meters. The available width along the street is 100m, while the maximum depth available is 200m. We want to have at least 10,000m2 in the lot. To avoid unsightly lots, the city requires that the longer dimension of any lot be no more than twice the shorter dimension. Formulate the minimum cost design problem.