What is the primary characteristic of an impulse turbine?

An impulse turbine is primarily characterized by the concept of using velocity to achieve energy conversion. In an impulse turbine, the flow of fluid is directed against turbine blades which are shaped to convert the kinetic energy of that fluid into mechanical energy as the rotor spins.

The defining feature of this process is the constant discharge velocity of the fluid as it moves out of the turbine. This means that the turbine generates energy through the rapid change in momentum of the fluid jet that strikes the turbine blades, rather than relying on pressure differences or variations in velocity for energy generation. The design of the turbine ensures that the fluid maintains a consistent speed as it exits the blades, which allows for efficient energy transfer and operational stability.

Understanding this characteristic is essential because it differentiates impulse turbines from other types, such as reaction turbines, which depend more on pressure changes and gradients to operate effectively.