1. What is Hydraulic Radius?

The hydraulic radius (R_h) is a measure of channel flow efficiency, defined as the ratio of the cross-sectional area of flow to the wetted perimeter. It's commonly used in fluid mechanics and hydraulic engineering.

2. How Does the Calculator Work?

The calculator uses the hydraulic radius formula:

Where:

• \( R_h \) — Hydraulic radius (m)
• \( A \) — Cross-sectional area of flow (m²)
• \( P \) — Wetted perimeter (m)

Explanation: The hydraulic radius represents the efficiency of a channel in conveying water. Larger values indicate more efficient flow.

3. Importance of Hydraulic Radius

Details: Hydraulic radius is crucial for calculating flow characteristics in open channels and pipes. It's used in Manning's equation for flow velocity and discharge calculations.

4. Using the Calculator

Tips: Enter the cross-sectional area in m² and wetted perimeter in m. Both values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between hydraulic radius and hydraulic diameter?
A: Hydraulic diameter is four times the hydraulic radius (D_h = 4R_h). Hydraulic diameter is used for non-circular pipes.

Q2: How does hydraulic radius affect flow rate?
A: Larger hydraulic radius generally means higher flow rates, as there's less friction relative to the flow area.

Q3: What's the hydraulic radius of a full circular pipe?
A: For a full circular pipe, R_h = D/4, where D is the pipe diameter.

Q4: Can hydraulic radius be greater than 1?
A: Yes, there's no upper limit to hydraulic radius. It depends on the channel geometry.

Q5: When is hydraulic radius most useful?
A: It's particularly useful in open channel flow calculations and in Manning's equation for natural and artificial channels.