Learning Unit 6

Question 1

List two (2) precautions against cavitation

Answer 1

Pressure of flowing fluid at any part should not fall below vapour pressure (1).
– Specific materials or coating (1) such as aluminium, bronze, and stainless steel (any one named – 1)
which are capitation resistant materials should be used

Question 2

What is the purpose of governing a turbine?

Answer 2

Governing of turbines is required to control the speed of turbine

Question 3

It is the ratio of power delivered to runner and power
available at inlet of the turbine.

Answer 3

Hydraulic Efficiency

Question 4

It is the ratio of the power produced at the shaft of the
turbine and power supplied to the runner of the turbine

Answer 4

Mechanical Efficiency

Question 5

It is the ratio of actual volume of water striking the
runner and the volume of water supplied to the turbine

Answer 5

Volumetric Efficiency

Question 6

It is the ratio of the power available at the shaft of the
turbine and power supplied at the inlet of the turbine

Answer 6

Overall Efficiency