1.
An inward flow reaction turbine
has inlet and outlet diameters of 1.2 m and 0.6 m respectively. The breadth at
inlet is 0.25 m and at outlet it is 0.35 m. At a speed of rotation of 250 rpm,
the relative velocity at entrance is 3.5 m/s and is radial. Calculate (i) the
absolute velocity at the entrance and the inclination to the target of the
runner (ii) discharge (iii) velocity of flow at outlet. [16.093 m/s; 3.299 m3/s and 5
m/s]
2. A centrifugal pump impeller whose
external and internal diameters are 400 mm and 200 mm respectively is running
at 950 rpm. The rate of flow through the pump is 0.035 m3/s. The
suction and the delivery heads are 5 m and 25 m respectively. The diameters of suction
and delivery pipes are 120 mm and 80 mm respectively. If the outlet vane angle
is 45̊, the flow
velocity is constant and equal to 1.8 m/s and power required to drive the pump
is 15 KW, Find the (i) Inlet vane angle (ii) ηo(iii) ηmax. [10.26̊, 61.76, 73.65]
3. A
Francis turbine has to be designed to develop 367.5 KW under a head of 70m
while running at N= 750 rpm. Ratio of width of runner to diameter of runner is
0.1; inner diameter is half the outer diameter. Flow ratio is 0.15, hydraulic
efficiency is 95% and mechanical efficiency is 84%. Flow velocity is constant
and discharge is radial at exit. Calculate (i) diameter of wheel (ii) discharge
(iii) guide vane angle (iv) runner vane angles at inlet and outlet.
4. The following data pertains to a Kaplan
Turbine,
Power available at shaft = 8850
KW
Net available head = 5.5 m
Speed ratio = 2.1
Flow ratio = 0.67
Overall efficiency = 85%
Assuming hub
diameter of the wheel is 0.35 times the outside diameter, determine (i) Runner diameter
(iii) Runner speed. [6.34m, 65.7 rpm]
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