Calculadora do Número de Froude — Formula

Froude Number

The Froude number characterises the ratio of flow inertia to gravitational effects in open-channel flow.

Formula

Fr = v / sqrt(g d)

  • *v* = mean flow velocity
  • *g* = gravitational acceleration
  • *d* = hydraulic depth (cross-section area divided by top width)

    • Fr < 1: subcritical (tranquil). Fr = 1: critical. Fr > 1: supercritical (rapid).

    Exemplo Resolvido

    River at 3 m/s with 1 m depth.

    1. Fr = v / sqrt(g d)
    2. Fr = 3 / sqrt(9.807 * 1)
    3. Fr = 3 / 3.131
    4. Fr = 0.958 (subcritical, but nearly critical)