Chapter 6, Problem 6.55P

3. In a radial flow pump ; the relationship between flow velocity : Vf , radius : R , blade width :b is given as ( using 1 : inler state and 2 :exit state )

In the jet impact experiment, water jet impacts on a curved vane in the vertical direction. As shown in the figure below, the exit has an angle with respect to the vertical direction. The distance from the nozzle to the vane surface at the exit is h. The water volume flow rate is measured to be Q, the density of water is p, and the cross section area of the nozzle is A₁. Assume that the flow has reached the steady state. (1) Use the Bernoulli's equation to determine the velocity Vout at the exit of the vane. Assume that friction between water and the curved vane can be neglected. (2) Apply the Reynolds transport theorem to derive the expression of the impact force F, on the curved vane (neglect the jet weight). (3) Under the condition of a fixed volume flow rate Q, determine the maximum impact force Fr,max that can be obtained when the angle varies (e.g. in different vane designs). Va out 9 Ao Vout h

4. A compressor draws in 500 min ft³ of air whose density is 0.079 lb and discharges lb At the suction, P, = 15 - lb it with a density of 0.304 and at the discharge, in? lb The increase in the specific internal energy is 33.8 Btu and the lb P2 = 80 in? Btu heat from the air by cooling is 13. Neglecting changes in the potential and lb Btu kinetic energy determine the work done on the air in min and in horsepower.