# Bernoulli's principle

## Description

Bernoulli’s principle states that for an inviscid flow, an increase in the speed of the fluid occurs simultaneously with an increase in dynamic pressure, an increase in kinetic energy and a decrease in static pressure and a decrease in the fluid’s potential energy. This form of Bernoulli’s principle is valid for incompressible flows (e.g. most liquid flows) and for compressible flows (e.g. gases) moving at low Mach numbers (usually less than 0.3). It is also valid at any arbitrary point along a streamline.

Related formulas## Variables

v | fluid flow speed at a point on a streamline (m/s) |

g | acceleration due to gravity (m/s^{2}) |

z | elevation of the point above a reference plane, with the positive z-direction pointing upward – so in the direction opposite to the gravitational acceleration (m) |

p | pressure at the chosen point (N/m^{2}) |

ρ | density of the fluid at all points in the fluid (kg/m^{3}) |

constant | constant (m^{2}/s^{2}) |