Hydraulic turbine or a water turbine is a rotary machine that converts potential energy and kinetic energy of water into mechanical work. In this article, we are going to discuss the Hydraulic Turbine along with its Definition, Classification, Advantages, Disadvantages & Applications.

Before going into the main topic, let’s see the difference between Turbine and pump.

Difference between Turbine and Pump:

If a machine transforms mechanical energy into hydraulic energy it is called a pump whereas, If a machine transforms hydraulic energy into mechanical energy it is called a Turbine.

Thus in turbines, fluid does work on the machine, and the machine produces power. but, the pump absorbs the power, and work is done on the fluid.

What is hydroelectric power?

The mechanical energy developed is utilized for running an electric generator which is directly coupled to the shaft of the turbine. The electric power developed by the electric generator is known as hydroelectric power.

So, the generation of hydroelectric power is cheaper than the other resources like coal, oil, etc.

Some parts of the hydroelectric power plant are a reservoir, dam, gates, surge tank, penstock, turbine, generator, etc.

Read:Hydroelectric Power Plant in Detailed

Classification of Hydraulic Turbines:

The types or Classification of Hydraulic Turbines are as follows.

The hydraulic Turbines were classified according to the following conditions.

  1. The direction of flow of water
  2. Available head
  3. Specific speed
  4. Action of water

An Explanation for the Classification of Hydraulic Turbines:

An Explanation for the Classification of Hydraulic Turbines is as follows.

1.Classification of Turbine based on the direction of flow of water:

If the water strikes the blades of the runner tangential to the path of rotation called Tangential flow.

Pelton wheel turbine
Pelton Turbine

Ex: Pelton wheel turbine.

Radial:  If the water strikes the blades of the runner radially and coming out axially called as Radial flow.

Ex: Francis turbine

Axial: In this flow, the water flows parallel to the axis of the turbine.

Ex: Kaplan turbine

2.Classification of Turbine based on Available head:

High head: The turbine capable of working under the high potential head of water above 300m

Ex: Pelton wheel turbine.  

Medium head: The turbine is capable of working under a medium range of potential head about 60m to 300m

Ex: Francis turbine.

Low head: The turbine is capable of working under a low range of potential head less than 60m

3.Classification of Turbine based on Specific speed:

Low Specific Speed: Turbine works in the range of 10-50.

Example: Pelton wheel turbine

Medium Specific Speed: Turbine works in the range of 50-350.

Example:Francis turbine

High Specific Speed: Turbine works in the range of 250-850.

kaplan turbine diagram
Kaplan Turbine

Example: Kaplan turbine

4.Classification of Turbine based on Action of water:

Impulse: There is no pressure drop on the runner/rotor. K.E of water coming from the jet is used to run the runner/rotor.

Ex: Pelton wheel turbine.

Reaction: There is a loss of K.E as well as pressure energy on the runners of the blade.

 Ex: Francis turbine

Let’s see the difference between impulse turbine and reaction turbine

Difference between Impulse and Reaction Turbine:

The difference between impulse and reaction turbine is shown below in a tabular column.

Impulse TurbineReaction Turbine
Available energy is converted into kinetic energyA major part of available energy is converted to pressure energy
Pressure in the turbine is constantPressure gradually reduces  while water flows on the turbine blades
The wheel and the blades should have access to free air and must not run fully.The blades are always under the action of pressure, the wheel must always run fully.
Only one face of the blade is activeBoth sides
Regulation of flow and power is easier without loss of energyDifficult
Used for high headsLow and medium heads
Efficiency is lessEfficiency is more
Energy transfer is a change in energyDue to a change in pressure head
Difference between Impulse and Reaction Turbine

Hydraulic Turbine Working Principle:

hydraulic turbines-Hydro-electric power plant
hydraulic turbines-Hydro-electric power plant

In general, the principal component of a turbine is a rotor. The rotor is a wheel carrying a number of plates and vanes on its periphery.

The rotor is housed in a stationary casing and water possesses a good amount of potential energy which is allowed to flow through pipes and finally discharged through nozzles and thus gaining kinetic energy.

Whenever the water strikes the runner and causes it to rotate, the mechanical energy developed is supplied to the generator coupled to the runner which generates electricity.

Hydraulic Turbine Advantages:

The Advantages of Hydraulic Turbine are as follows.

  • Hydraulic Turbine’s running coast is less compared to other turbines.
  • It is a renewable source of energy.
  • The efficiency of this system is high.
  • Environmental pollution is almost zero.

Hydraulic Turbine Disadvantages:

The disdvantages of Hydraulic Turbine are as follows.

  • The installation cost is very high.
  • It can be placed at only those regions where there is a surplus of water.
  • The population of aquatic animals can be impacted.

Hydraulic Turbine Applications:

The applications of Hydraulic Turbine are as follows.

  • It is used for the generation of electric power in dams.
  • It will control the floods in the rivers.
  • The water which stays in a reservoir can be used for agriculture purposes.

This is the detailed explanation of Hydraulic Turbines. If you have any doubts, you can please let us know, so that we can solve it soon.

More Resources:

Kaplan Turbine
Pelton Wheel Turbine
Hydroelectric Power plant

References [External Links]:


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Mohammed SHAFI

Mr. Mohammed Shafi is an Assistant Professor at Sreenidhi Institute of Science & Technology. By education, he is a Mechanical Engineer and expertise in CAD & CAM. Mechanical Students is his first...

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