1. What is Hydraulic Jump Froude Number?

The Froude number (Fr) is a dimensionless number that characterizes the flow regime in open channel hydraulics. It's particularly important in analyzing hydraulic jumps, which occur when a supercritical flow transitions to subcritical flow.

2. How Does the Calculator Work?

The calculator uses the Froude number equation:

Where:

• \( v \) — Flow velocity (m/s)
• \( g \) — Acceleration due to gravity (m/s²)
• \( d \) — Flow depth (m)

Explanation: The Froude number compares the flow velocity to the wave velocity in the fluid. When Fr > 1, the flow is supercritical; when Fr < 1, the flow is subcritical.

3. Importance of Froude Number

Details: The Froude number is crucial for designing hydraulic structures, predicting energy dissipation in hydraulic jumps, and analyzing flow transitions in open channels.

4. Using the Calculator

Tips: Enter velocity in m/s, gravity in m/s² (default is 9.81), and depth in meters. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What does the Froude number indicate?
A: The Froude number indicates the flow regime: Fr < 1 (subcritical/tranquil), Fr = 1 (critical), Fr > 1 (supercritical/rapid).

Q2: What is a typical Froude number for hydraulic jumps?
A: Hydraulic jumps typically occur when a supercritical flow (Fr > 1) transitions to subcritical flow (Fr < 1).

Q3: How does the Froude number affect energy dissipation?
A: Higher initial Froude numbers result in more turbulent jumps with greater energy dissipation.

Q4: Can this calculator be used for any fluid?
A: The equation is valid for any Newtonian fluid, but gravity (g) should be adjusted for non-Earth conditions.

Q5: What are practical applications of this calculation?
A: Used in designing spillways, stilling basins, weirs, and other hydraulic structures where energy dissipation is needed.