An inward flow radial turbine (see Fig. P5.89) involves a nozzle angle, (alpha_{1}), of (60^{circ}) and an

Question:

An inward flow radial turbine (see Fig. P5.89) involves a nozzle angle, $\alpha_{1}$, of $60^{\circ}$ and an inlet rotor tip speed, $U_{1}$, of $6 \mathrm{~m} / \mathrm{s}$. The ratio of rotor inlet to outlet diameters is 1.8. The absolute velocity leaving the rotor at section (2) is radial with a magnitude of $12 \mathrm{~m} / \mathrm{s}$. Determine the energy transfer per unit mass of fluid flowing through this turbine if the fluid is

(a) air,

(b) water.

Figure P5.89