Skip to main content

Formula Bernoulli equation Static pressure    Mass density    Height    Flow velocity   

Formula
Formula: Bernoulli equation
Bernoulli principle applied to a flowing liquid

Total pressure

Unit
Constant total pressure of a stationary, non-viscous, incompressible fluid or gas along a streamline. The total pressure here is the sum of the dynamic pressure \(\frac{1}{2} \rho \, v^2\), hydrostatic pressure \(\rho \, g \, h\) and the static pressure \(\mathit{\Pi}_{\text{st}}\).

The Bernoulli equation results from the law of conservation of energy.

Static pressure

Unit
Static pressure is the pressure that a body would feel if it were moving with the flow. The static pressure results from the potential energy of the flowing fluid.

Mass density

Unit
Mass per volume of the fluid or gas.

Height

Unit
Height of the considered streamline of a fluid or gas above the ground (or other specified zero point).

Flow velocity

Unit
Flow velocity is the average velocity of the directed motion of the fluid or gas.

Gravitational acceleration

Unit
On Earth, the gravitational acceleration is approximately \( g = 9.8 \, \frac{\mathrm{m}}{\mathrm{s}^2} \).