For a 1:m scale model of a turbine, the specific speed of the model Nₛₘ is related to the prototype specific speed Nₛₚ as Nₛₘ =
- ANₛₚ/m
- BmNₛₚ
- CNₛₚCorrect
- D(Nₛₚ)1/m
Solution
Concept
Specific speed of model and prototype
Formula
Nₛₘ = Nₛₚ
Step-by-step solution
1. Specific speed is the same for model and prototype.
Explanation
It is an index of dynamic similarity.
Why the other options are wrong
Other options change Ns with scale.
Shortcut
Nₛ model = Nₛ prototype.
Correct answer: C) Nₛₚ