Moving blading where the space between blades is smaller at the exhaust than at the inlet and energy transfer results in a decrease in steam pressure and velocity is called what?

Moving blading where the space between blades is smaller at the exhaust than at the inlet and energy transfer results in a decrease in steam pressure and velocity is called what?

• A. Impulse Blading
• B. Mixed Blading
• C. Reaction Blading
• D. Radial Blading

Answer: (C)

This describes reaction blading. In a reaction blade row, the space between blades narrows from the inlet to the outlet, so the flow area decreases in the direction of travel. As the steam passes through these blades, energy is transferred to the rotor not just by deflecting the flow but also by a pressure drop across the blade row. That pressure drop through the moving blades is a defining feature of reaction blading, and it’s what causes the steam pressure to fall as it traverses the blade passage. This is different from impulse blading, where the energy transfer happens mainly through a change in momentum after the steam is directed by a nozzle and the pressure across the blade remains essentially constant.

This describes reaction blading. In a reaction blade row, the space between blades narrows from the inlet to the outlet, so the flow area decreases in the direction of travel. As the steam passes through these blades, energy is transferred to the rotor not just by deflecting the flow but also by a pressure drop across the blade row. That pressure drop through the moving blades is a defining feature of reaction blading, and it’s what causes the steam pressure to fall as it traverses the blade passage. This is different from impulse blading, where the energy transfer happens mainly through a change in momentum after the steam is directed by a nozzle and the pressure across the blade remains essentially constant.