Fluid mechanics: coefficient of discharge for an external mouthpiece For a sharp-edged external mouthpiece (running free), identify the standard coefficient of discharge value used in calculations. Choose the correct numerical value.
Mechanical Engineering
Hydraulics and Fluid Mechanics
Difficulty: Easy
Choose an option
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A0.375
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B0.5
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C0.707
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D0.855
Answer
Correct Answer: 0.855
Explanation
Concept/ApproachThe coefficient of discharge Cd for an external mouthpiece (free discharge) is empirically established around 0.85–0.86 for water at normal conditions. This accounts for contraction and velocity effects at the mouthpiece.
Final Answer0.855