Hydraulic Radius Calculator

Calculate the hydraulic radius for open channel flow by dividing the cross-sectional area by the wetted perimeter.

Input Parameters

Horizontal:Vertical ratio for channel sides (e.g., 1 for 1:1 slope)

Calculation Results

Calculation Formula

Hydraulic Radius (R) = Area (A) / Wetted Perimeter (P)

Where:
Area (A) = Width × Depth + (0.5 × Side Slope Ratio × Depth²)
Wetted Perimeter (P) = Width + 2 × (Depth + Side Slope Ratio × Depth)

Hydraulic Radius Calculator Usage Guide

Learn how to use the Hydraulic Radius Calculator and its working principles in open channel hydraulics.

What is Hydraulic Radius?

The hydraulic radius is a crucial parameter in open channel flow calculations. It's defined as the cross-sectional area of flow divided by the wetted perimeter. The hydraulic radius helps determine the efficiency of flow in channels and pipes.

How to Use This Calculator

  1. Enter the Channel Width in meters (m).
  2. Enter the Channel Depth in meters (m).
  3. Enter the Side Slope Ratio (Horizontal:Vertical). For example, enter "1" for a 1:1 slope (45° angle), or "2" for a 2:1 slope.
  4. Click the Calculate button to compute the hydraulic radius and related parameters.
  5. Use the Reset button to clear all inputs and start over.

Applications

The hydraulic radius is used in various engineering applications including:

  • Designing canals and drainage channels
  • Calculating flow capacity in open channels
  • Determining water velocity and channel capacity
  • Hydraulic model design and scaling

Important Notes

For channels with different side slopes or complex cross-sections, the formula used in this calculator provides an accurate estimation of the hydraulic radius. The calculator assumes a rectangular channel with sloped sides as defined by the side slope ratio.