The rotating parts of a hydroelectric power plant having power capacity \(\dot{W}\) have a rotational synchronous speed \(\dot{n}\). The weight of the rotating parts (the hydroturbine and its electric generator) is supported in a thrust bearing having annular form between \(D\) and \(d\) diameters as sketched. The thrust bearing is operated with a very thin oil film of thickness \(e\) and dynamic viscosity \(\mu\). It is assumed that the oil is a Newtonian fluid and the velocity is approximated as linear in the bearing. Calculate the ratio of lost power in the thrust bearing to the produced power in the hydraulic power plant. Use \(\dot{W}=48.6 \mathrm{MW}, \mu=0.035 \mathrm{~Pa} \cdot \mathrm{s}, \dot{n}=500 \mathrm{rpm}\), \(e=0.25 \mathrm{~mm}, D=3.2 \mathrm{~m}\), and \(d=2.4 \mathrm{~m}\).

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- Oil D (load) @ = const. Oil