Question

what are the limitations of Bernoulli's principle​

Answer 1

$\red{\bold{\underline{{ Limitations \: of\: Bernoulli's \: Principle :}}}}$

1. Bernoulli's equation ideally applies to Fluids with zero viscosity or non viscous fluid. In case of viscous Fluids we need to take into account the work done against viscous drag.

2. Bernoulli's equation has been trapped on the assumption that there is no loss of energy due to friction. But in practice, when fluid flow some of their kinetic energy gets converted into heat due to work done against the internal forces of friction or viscous force.

3. Bernoulli's equation is applicable only to incompressible Fluids because it does not take into account the elastic energy of the Fluids.

4. Bernoulli's equation does not take into consideration the angular momentum of the following. So it cannot be applied when fluid flows along the curved path .

5. Bernoulli's principle is applicable only to streamline flow of a fluid and not when the flow is in troublent.

Answer 2

Limitations of Bernoulli's equation:

1. The above equation has been derived by assuming that the velocity of every element of the liquid across any cross-section of the peipeis uniform. Practically,it is not true. The elements of the liquid in the innermost layer have the maximum velocity. The velocity of the liquid decreases towards the walls of the pipe. Therefore, we should take into account the mean velocity of the liquid.

2. While deriving Bernoulli's equation, the visous drag of the liquid has not been taken into consideration. The viscous drag comes into play, when a liquid is in motion.

3.Bernoulli's equation has been derived on the assumption that there appears no loss of energy, when a liquid is in motion. In fsct, some kinetic energy is converted into heat energy and a part of it is lost due to shear force.

4. If the liquid is flowing along a curved path, the energy due to centrifugal force should also be taken into consideration.