Fluid Dynamics

In addition to the energy required for the height to be pumped, energy loss due to friction and the difference in inlet/outlet pressure must be added. The total head is the sum of all these energies expressed as the pump's head.

The equation relating pressure drop and flow velocity in laminar pipe flow is called the Hagen-Poiseuille equation. This article explains the derivation of the Hagen-Poiseuille equation.

When a fluid loses energy due to friction with a wall or between fluids, it is called pressure loss. In this article, we will introduce a calculation method for pressure loss in a piping flow path, which is frequently calculated in practice.

Fanning's equation is used to calculate the pressure drop in a straight pipe when calculating the pump head. If the pump head is determined only by the actual head without considering the pressure drop in Fanning's equation, the pump will not be able to transfer the fluid to the desired location because of the loss of energy due to friction between the fluid and the piping.

The energy conservation law for fluids is called Bernoulli's principle in particular. Thanks to Bernoulli's principle, engineers can calculate how much energy and pump lift is needed to lift a fluid to a given height.