Fluid mechanics: definition of geometric similarity between model and prototype Compare model and prototype for geometric similarity in hydraulic/thermal machinery modeling. Choose the correct statement that defines geometric similarity.
Mechanical Engineering
Hydraulic Machines
Difficulty: Easy
Choose an option
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AThey have identical velocities at corresponding points.
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BThey are equal in both size and shape.
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CThey are identical in shape but differ only in size (all linear dimensions are in a constant scale ratio).
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DThey have identical forces acting at corresponding points.
Answer
Correct Answer: They are identical in shape but differ only in size (all linear dimensions are in a constant scale ratio).
Explanation
Concept
- Geometric similarity means the model and prototype are the same shape; all corresponding linear dimensions are in a constant ratio (scale). Size may differ, but shape must be identical.
- Dynamic or kinematic similarity adds matching force/velocity ratios, but those are separate requirements.
Why the other options are incorrect
- Identical velocities or forces are aspects of kinematic or dynamic similarity, not strictly geometric.
- Equal size and shape implies the same object, not a scale model.
Final AnswerIdentical in shape but different in size according to a constant scale.