# Darcy's law

## Description

Describes the flow of a fluid through a porous medium, for slow, viscous flow. The total discharge, is equal to the product of the intrinsic permeability of the medium, the cross-sectional area to flow, and the total pressure drop, all divided by the viscosity, and the length over which the pressure drop is taking place.

Related formulas## Variables

Q | Total discharge (m^{3}/s) |

k | Coefficient of permeability of the soil (m^{2}) |

A | The cross-sectional area to flow (m^{2}) |

P_{b} | Initial preassure (Pa) |

P_{a} | Final preassure (Pa) |

μ | Viscosity (Pa*s) |

L | The length over which the pressure drop is taking place (m) |