Mechanical Engineering - Hydraulics and Fluid Mechanics - Discussion

@S.Ata.

How option C is correct? Explain.

A is correct.

Works on energy conservation.

All assumptions are taken when deriving the Bernoulli's equation:-

i. Fluid is ideal and incompressible.
ii. flow is steady
iii. Flow is along the streamline ie. One dimensional.
iv. The velocity is uniform over the section and is equal to mean velocity.
v. The only forces acting on the fluid are the gravity forces and pressure forces.

So Given answer Option D is correct.

I think about option A- as Bernoulli equation is basically conservation of mechanical energy. So net mec energy is conserved.

Option B- is incorrect because the equation is applicable in the case of venturi meter where velocity is not uniform. So the assumption of uniform velocity is contradictory with venturi meter. Option C is standard wrong.

B is incorrect as according to Bernoulli, the sum of pressure, potential and kinetic heads are same throughout the flow. So, with the change in velocity pressure may vary though satisfying Bernoulli.

I think option c is wrong.

Apart from gravity force pressure force is also taken into consideration as per the Euler's criteria.

So I don't agree with option C.