Maximum propulsive efficiency for jet-propelled ship with side inlets A ship uses jet propulsion with inlet orifices at right angles to its motion. What is the maximum possible propulsive efficiency for this configuration? Choose the correct percentage.
Mechanical Engineering
Hydraulic Machines
Difficulty: Medium
Choose an option
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A40%
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B50%
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C60%
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D80%
Answer
Correct Answer: 50%
Explanation
Concept Propulsive efficiency ηp = (useful power to ship) / (jet power), maximized when jet and ship speeds are optimally related.
Result for side inlets For inlets at right angles to motion, analysis of momentum and energy shows a theoretical maximum ηp of 50%.
Common pitfalls Confusing this with axial inlets or aircraft jets where the optimal values differ.
Final Answer50%