An impulse turbine utilizing one row of stationary steam nozzles to drive two rows of rotating blades is called what?

The correct answer identifies a specific type of steam turbine design. An impulse turbine is structured so that steam expands through stationary nozzles, converting thermal energy into kinetic energy. In the case of a velocity-compound turbine, the design features one row of stationary steam nozzles that produce a jet of steam to strike and rotate the first row of blades. After the steam has passed the first set of blades, it enters a second set of rotating blades.

This configuration allows for more efficient energy extraction because the steam undergoes a change in velocity as it passes through the nozzles and then interacts with multiple sets of blades. The design effectively compounds the velocity impacts on the turbine, maximizing the work done by the steam on the rotating components.

Understanding the mechanics of a velocity-compound turbine is crucial because this type of turbine is commonly used in high-efficiency applications within various steam systems, emphasizing the importance of nozzle and blade interaction in turbine performance.