1. According to the Type of Energy at Inlet

Impulse Turbine

If at the inlet of the turbine, the energy available is only kinetic energy, the turbine is known as impulse turbine. As the water flows over the vanes, the pressure remains atmospheric from inlet to outlet of the turbine.

Reaction Turbine

If at the inlet of the turbine, the water possesses kinetic energy as well as pressure energy, the turbine is known as reaction turbine. As the water flows through the runner, the water is under pressure and the pressure energy goes on changing into kinetic energy. The runner is completely enclosed in an air-tight casing and is fully filled with water.

2. According to the Direction of Flow Through Runner

• Tangential Flow Turbine: If the water flows along the tangent of the runner, the turbine is known as tangential flow turbine.
• Radial Flow Turbine: If the water flows in the radial direction through the runner, the turbine is called radial flow turbine.
• Inward Radial Flow Turbine: If water flows from outwards to inwards radially, the turbine is known as inward radial flow turbine.
• Outward Radial Flow Turbine: If water flows radially from inwards to outwards, the turbine is known as outward radial flow turbine.
• Axial Flow Turbine: If the water flows through the runner along the direction parallel to the axis of rotation of the runner, the turbine is called axial flow turbine.
• Mixed Flow Turbine: If the water flows through the runner in the radial direction but leaves in the direction parallel to the axis of rotation of the runner, the turbine is called mixed flow turbine.

3. According to the Head at the Inlet of Turbine

• High Head Turbine
• Medium Head Turbine
• Low Head Turbine

4. According to the Specific Speed of the Turbine

• Low Specific Speed Turbine
• Medium Specific Speed Turbine
• High Specific Speed Turbine