GE 9HA, an impulse type turbine or reaction type?


Most turbines made today have blades that are a "mix" of both of the primary types of blades--reaction and impulse. By that I specifically mean that individual blades can have surfaces that exhibit properties of both types of blades, reaction and impulse. This was not possible in the early days of turbine manufacturing as the machines used to form turbine blades weren't capable of making such intricate shapes. But with todays manufacturing machines and processes it is entirely possible and makes the turbine sections "shorter" (meaning less sets of rows of blades) because blades have the ability to act as both types instead of just one or the other.

(By the way, this is true for both combustion (gas) and steam turbines.)

By the way, to operators, technicians and even engineers working on modern-day turbines it makes no difference whether the blades are reaction or impulse or a combination of the two. The design is what it is--and the manufacturer has incorporated the proper design characteristics into all aspects of the turbine(s), not just the turbine blades (or buckets as some manufacturers call turbine blades) but the nozzles and diaphragms and interstage seals--everything.