Bernoulli's equation

p+\tfrac12\rho v^2=\text{const}

Result unit: Pa (pascal)

What it describes

The sum of the static and dynamic pressure along a streamline of a fluid is constant; where the fluid flows faster, the pressure is lower.

p

static pressure

[Pa]

\rho

density of the fluid

[kg/m³]

v

flow speed

[m/s]

In a fluid stream, where the fluid flows faster the pressure is lower. This explains the lift of a wing and the operation of an atomizer.

Flow of liquids and gases; wings, venturi constrictions, atomizers.

In which cross-section of a pipe — the narrower or the wider — is the pressure lower?

SubstitutionIn the narrower cross-section the speed

v

is higher.

ResultIn the narrower cross-section (higher speed) the pressure is lower.

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