We all know the law of conservation of energy. Don’t think much about it if you cannot remember. It states that “Energy is neither created nor destroyed- only converted from one form of energy to another.

So wasting no time, let’s jump into our topic. It’s **Bernoulli’s equation** that we will know and learn.

So Bernoulli’s can be considered to be a statement of the conservation of energy principle appropriate for flowing fluids.

## History

In the 1700s, **Daniel Bernoulli** investigated the forces present in a moving fluid. This slide shows one of many forms of Bernoulli’s equation. Taking his discoveries further, Daniel Bernoulli returned to his earlier work on Conservation of Energy after discovering how to measure blood pressure along with Euler. The principle is named after Daniel Bernoulli, who published it in his book Hydrodynamica in 1738.

It was known that a moving body exchanges its kinetic energy for potential energy when it gains height. Daniel realized that similarly, a moving fluid exchanges its kinetic energy for pressure.

## The Law And Equation

### Bernoulli’s principle:

**At points along a horizontal streamline, higher pressure regions have lower fluid speed and lower pressure regions have higher fluid speed.**

Bernoulli’s principle states that for an incompressible flow of a non-conducting fluid, an increase in the fluid’s speed occurs simultaneously with a decrease in pressure or a decrease in the fluid’s potential energy.

This formula highlights Bernoulli’s principle since if the speed v of fluid is larger in a given region of streamline flow, the pressure P must be smaller in that region (which is Bernoulli’s principle). An increase in speed v must be accompanied by a simultaneous decrease in the pressure P in order for the sum to always add up to the same constant number.

In plain language, the Bernoulli equation says that if an incompressible fluid flows through different sizes of pipes, the fluid velocity changes. This change creates an acceleration in the system which creates different forces and pressures on the pipe’s cross-section area.

This inverse relationship between the pressure and speed at a point in a fluid is called Bernoulli’s principle.

The Bernoulli equation is a correlation from the conservation equations to show a relation between velocity, elevation, and pressure in a nonviscous (frictionless) fluid. A consequence of this law is that if the velocity increases then the pressure falls.

Bernoulli’s equation can be viewed as a conservation of energy law for a flowing fluid.

Since the quantity **P+ 1/2ρv^2 + ρgh** is the same at every point in a streamline, another way to write Bernoulli’s equation is,

P+ 1/2ρv^2 + ρgh = constant

Bernoulli’s Principle and equations have a lot of applications in the real world. It includes:

- To find Pressure flow through a Nozzle.
- To find Velocity through a siphon.
- A fitting example of an application of Bernoulli’s Equation in a moving reference frame is finding the pressure on the wings of an aircraft flying with a certain velocity. Here the equation is applied between some point on the wing and a point in free air.
- For the efficient design of the hydraulic systems in civil engineering, it is very important to first analyze the flow of fluid through the system.

So, those were a few things about Bernoulli’s equation