# Froude Number

### Description

Calculate the Froude Number.

### Usage

1 | ```
froude(Q, g, A, DH)
``` |

### Arguments

`Q` |
Flow rate [ |

`g` |
Gravitational acceleration [ |

`A` |
Flow area [ |

`DH` |
Hydraulic depth [ |

### Details

The Froude number is a dimensionless measure of bulk flow characteristics that represents the relative importance of inertial forces and gravitational forces. For open channel flow, the Froude number of open channel flow is defined as

*Fr = \frac{v}{√{gD_H}}*

where *v = \frac{Q}{A}* is the flow velocity, *g* is the gravitational
acceleration and *D_H* is the hydraulic depth. The Froude number is related
to the energy state of the flow and can be used to identify flows as
either supercritical (*Fr < 1*) or subcritical (*Fr > 1*).

### Value

The Froude Number (dimensionless).

### Examples

1 2 3 |