According to Euler's equation, what happens to the velocity of the inviscid flow if the pressure increases?

No change

Increases

Decreases

Becomes zero

Correct Answer : Decreases

Explanation : According to the Euler, the relation between velocity and pressure for an inviscid fluid is given by dp = – ρVdV. According to the relation, due to the presence of negative sign, when the pressure increases velocity decreases and vice versa. The same concept is also explained using Bernoulli’s principle.

Recently Updated in Aerodynamics Questions

If the Laplace equation is satisfied by the velocity potential, then the fluid flows.

True

False

Can Not Say

None of the above

Correct Answer : Option (A) : True

Explanation : For the fluid to flow, it is essential for the velocity potential ? to satisfy the Laplace equation. If the condition is not met, the fluid does not flow and has zero velocity.

Thus, the condition for the fluid to flow is :

What is the nature of the flow having a velocity potential?

Viscous

Inviscid

Rotational

Irrotational

Correct Answer : Option (D) : Irrotational

Explanation : For irrotational flow, curl of velocity vector yields zero. In case the curl of any vector is zero i.e.∇ × V = 0, where V is a vector, it is also expressed in the form of ∇ζ where ζ is a scalar function. In case of irrotational flow, velocity potential ? is the scalar function. Hence if the flow has a velocity potential, it automatically implies that it is irrotational.