Chemical Engineering - Fluid Mechanics - Discussion

The correct answer is: The fluid is non-viscous.

Explanation:

Euler’s equation of motion is derived from Newton’s second law applied to a fluid element, neglecting viscous forces. It applies to inviscid (non-viscous), incompressible or compressible flows and is expressed as:

frac{dV}{dt} = -frac{1}{ρ} \nabla P + \vec{g}

To integrate Euler’s equation (e.g., to get Bernoulli’s equation), the key assumptions are:

Non-viscous fluid (so viscous/shear stresses are zero).
Steady flow.
Incompressible (sometimes, but not strictly required for integration).
Along a streamline (for Bernoulli).
Irrotational (only if Bernoulli is to be applied across streamlines).

Therefore, the most critical assumption enabling the integration of Euler’s equation is:
The fluid is non-viscous.

I think A and B are correct.

However, the question is asked from which assumption Euler’s equation can be integrated?

Then the answer is incompressible fluid.

We shall derive Euler's equation in 3-Dimension in Cartesian coordinate system. Euler's Equation can also be derived from the Navier Stokes Equation with Steady and Non-Viscous flow.

Yes. The Correct Answer is B.

The correct answer is B.