Question

As water flows through the runner of a reaction turbine, the pressure acting on it would vary from:
1. atmospheric pressure to vacuum
2. more than atmospheric pressure to vacuum
3. less than atmospheric pressure to zero gauge pressure
4. atmospheric pressure to more than atmospheric pressure

Answer 1

Correct Answer - Option 2 : more than atmospheric pressure to vacuum

Explanation:

Reaction turbine:

A reaction turbine is a type of turbine that develops torque by reacting to the pressure or weight of a fluid. The operation of a reaction turbine is described by Newton's third law of motion. There are different types of a reaction turbine,

1- Francis turbine

2- Kaplan turbine

3- Modern Francis turbine

• The water flow over the moving vane creates a pressure difference across due to the Aerodynamic shape of the vane due to which water will apply lift force also known as reaction force both impulse and reaction force rotate the runner.
• The pressure of water in the reaction turbine runner varies from more than atmospheric to vacuum. At runner inlet, the pressure is more than atmospheric pressure and at runner outlet pressure is less than atmospheric(vacuum).