1. What is Wetted Surface Area?

Wetted Surface Area of Channel [length²] is the total area of outer surface in contact with the surrounding water. It represents the cross-sectional area of flow in an open channel.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( A \) — Wetted Surface Area (m²)
• \( D_{Hydraulic} \) — Hydraulic Depth (m)
• \( T \) — Top Width (m)

Explanation: Hydraulic Depth is defined as depth which is in contact with water, and Top Width is defined as the width at the top of the section.

3. Importance of Wetted Surface Area Calculation

Details: Accurate calculation of wetted surface area is crucial for hydraulic engineering, flow rate calculations, channel design, and flood management. It helps determine the cross-sectional area available for water flow in open channels.

4. Using the Calculator

Tips: Enter hydraulic depth in meters, top width in meters. All values must be valid positive numbers greater than zero.

5. Frequently Asked Questions (FAQ)

Q1: What is the difference between hydraulic depth and hydraulic radius?
A: Hydraulic depth is the cross-sectional area divided by the top width, while hydraulic radius is the cross-sectional area divided by the wetted perimeter.

Q2: When is this formula applicable?
A: This formula is primarily used for open channel flow calculations in hydraulic engineering and water resources management.

Q3: What are typical units for these measurements?
A: Typically measured in meters for both hydraulic depth and top width, resulting in square meters for wetted surface area.

Q4: Does this formula work for all channel shapes?
A: This specific formula A = D_Hydraulic × T is a general relationship. For specific channel shapes (rectangular, trapezoidal, circular), additional geometric relationships may apply.

Q5: How accurate is this calculation?
A: The calculation is mathematically exact based on the input values. Accuracy depends on the precision of the measured hydraulic depth and top width values.