The open water characteristics of a propeller is shown in the figure. Match the labels in Column 1 with the corresponding descriptions in Column 2.
The open water characteristics of a propeller is shown in the figure. Match the labels in Column 1 with the corresponding descriptions in Column 2.
Show Hint
- Bollard pull condition corresponds to zero ship speed. - Feathering minimizes drag when the propeller is not in use.
- Wind milling occurs when the propeller spins freely in the flow.
2. Efficiency curves help determine the optimal operating point.
- O - I; P - II; Q - III; R - IV
- O - I; Q - III; P - II; R - IV
- O - R; I - III; P - IV; Q - II
- P - I; Q - II; R - III; O - IV
The Correct Option is A
Solution and Explanation
Step 1: Analyze the graph. The graph represents the open water characteristics of a propeller. The axes are: - \( K_T \): Thrust coefficient, - \( 10K_Q \): Torque coefficient, - \( \eta_e \): Efficiency. Each labeled point corresponds to a specific operating condition of the propeller.
Step 2: Match the labels with their descriptions. O: Bollard pull condition (maximum thrust at zero speed). P: Feathering condition (propeller blades aligned with the flow to minimize drag). Q: Wind milling condition (propeller rotating due to external flow when not powered). R: Efficiency curve (shows the efficiency variation with operating conditions).
Conclusion: The correct match is \( \mathbf{O - I; P - II; Q - III; R - IV} \). The correct option is \( \mathbf{(A)} \).
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