Step 1: Understanding the Concept:
Hydraulic radius (\(R\)) is a derived parameter used in fluid mechanics to characterize the "efficiency" of a flow cross-section.
It is used in Manning's and Chezy's equations for calculating flow velocity in open channels and pipes.
Step 2: Key Formula or Approach:
The hydraulic radius is defined as the ratio of the cross-sectional area of the flow to the wetted perimeter.
\[ R = \frac{A}{P} \]
Where:
- \(A\) = Cross-sectional area of water (\(m^2\)).
- \(P\) = Wetted perimeter (\(m\)), which is the length of the channel boundary in contact with the water.
Step 3: Final Answer:
The definition is \(R = \frac{A}{P}\).