The high pressure turbine element is normally classified as what type of turbine?

The high pressure turbine element is classified as an impulse type turbine because it operates based on the principle of converting kinetic energy from high-velocity steam into mechanical work through a series of rotor blades. In an impulse turbine, the steam is directed through nozzles that convert the pressure energy into velocity, creating high-speed jets. These jets then strike the blades, causing the rotor to spin.

The design of impulse turbines focuses on the initial expansion of steam in the nozzles, which means that pressure drop occurs before the steam reaches the blades. This is characteristic of impulse turbines, as they primarily harness the momentum of the jet created by the steam rather than relying on gradual pressure changes throughout the turbine.

In contrast, reaction turbines utilize a combination of pressure drop and blade reaction to generate movement, meaning that they operate more efficiently during slower speed applications. The centrifugal type is relevant for applications involving fluids and is not used to describe turbines meant for high-speed steam applications. Finally, axial type generally refers to turbines where the fluid flows parallel to the axis of rotation, which is not indicative of the impulse mechanism used in high-pressure turbine elements.