Q10Basic Mechanical Engineering
Question
2 marks
Differentiate between impulse and reaction turbine?
Answer
Impulse turbines operate purely by the kinetic impact of high-velocity water jets, while reaction turbines utilize both the pressure and kinetic energy of the flowing fluid.
In an Impulse Turbine (like the Pelton Wheel), the entire pressure drop occurs in the stationary nozzle, creating a massive, high-speed water jet that slams into the rotor buckets. The pressure across the rotor is constant atmospheric. In a Reaction Turbine (like the Francis or Kaplan), the rotor is fully submerged, and the water pressure continuously drops as it actively flows over the specially shaped moving blades, generating aerodynamic lift/thrust.