Fluid Mechanics: Tutorials - Unit 4

1.         A single acting reciprocating pump has a 15 cm piston with a crank radius 15 cm. The delivery pipe is 10 cm diameter. At a speed of 60 rpm, 310 lps of water is lifted to a total height of 15 cm. Find the slip, co-efficient of discharge and theoretical power in KW required to drive the pump.

2.         A single acting reciprocating pump has the following data

            Cylinder diameter                   =          10 cm

            Stroke                                      =          25 cm

            Static suction head                  =          4 m

            Diameter of suction pipe         =          5 cm

            Suction pipe length                 =          6 m

            Crank speed                            =          30 rpm

            Delivery pipe diameter            =          5 cm

            Length of the delivery pipe    =          25 m

            Static delivery head                =          16 m

Estimate the pressure head on the piston at (i) beginning, (ii) mid and (iii) end of the suction and delivery strokes. Assume Patm = 10 m of water and f=0.02. [2.982, 5.698, 9.018]; [28.576, 17.258, 3.424]

3.         A single acting reciprocating pump has a 20 cm piston with a crank of radius of 40 cm. The delivery pipe is 10 cm diameter and 45 m long. Water is lifted to a height of 40 m above the axis of the cylinder. Find the maximum speed at which the pump can be run without cavitation. Assume atmospheric pressure = 9.75 m water (abs) and cavitation occurs at 2.75 m water (abs). [24.17 rpm]

4.        A centrifugal pump impeller has an outer diameter of 30 cm and an inner diameter of 15 cm. the pump runs at 1200 rpm. The impeller vanes are set back at an angle of 30̊at the outlet. If the velocity of flow constant at 2.0 m/s, calculate
        (i) The velocity and direction of the water at outlet [15.51 m/s]

(ii) The head developed if η_mano is 0.85 [25.13]

(iii) The blade inlet angle [11.98]