Hydraulic turbines selection by head range: choose the turbine for very low heads (0–25 m) Given a site with an available water head in the range of 0 to 25 m. Which turbine type is generally preferred for high discharge and low head conditions? Choose the correct option.
Mechanical Engineering
Hydraulic Machines
Difficulty: Easy
Choose an option
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APelton wheel
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BKaplan turbine
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CFrancis turbine
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DNone of these
Answer
Correct Answer: Kaplan turbine
Explanation
Concept / ApproachTypical head ranges: Pelton (high head, low flow), Francis (medium head), Kaplan/propeller (low head, high flow).
ReasoningFor heads 0–25 m with large discharge, axial-flow Kaplan turbines are preferred due to adjustable runner blades that maintain high efficiency at low heads.
Common pitfallsConfusing Francis (medium head ~25–250 m) with Kaplan (low head) or Pelton (very high head).
Final AnswerKaplan turbine.