What are the required assumptions/conditions that need to be met in order to apply Bernoulli's equation to a fluid?

Answer 1

We can use Bernoulli's equation for ideal fluids. It means they are

1. incompressible
2. inviscid
3. irrotational
4. flow of them - laminar
5. forces applied to fluids are conservative.

Answer 2

The following assumptions need to be met in order to apply Bernoulli's equation to a fluid:

1. Fluid must be in steady flow (velocity, density and pressure remains constant throughout the flow)
2. Fluid must be incompressible (density of fluid does not change with time)
3. Fluid must be inviscid
4. Fluid must be irrotational
5. No external force acts on the fluid
6. There is no energy loss during the flow