Question

Three flows named as 1,2 and 3 are observed. The flow velocities are v1 and v2. If all other geometrical factors remain the same along with the fluid considered, flow is more likely to be laminar?

(a) flow 1 if v1 > v2

(b) flow 2 if v1 > v2

(c) always flow 1

(d) always flow 2

I got this question in quiz.

My question is taken from Types of Fluid Flow topic in chapter Kinematics of Flow and Ideal Flow of Fluid Mechanics

Answer 1

The correct option is (d) always flow 2

Explanation: Flows can be characterized as laminar or turbulent on the basis of Reynold’s number Re = ρvd / μ, where ρ is the density, d is the pipe diameter and μ is the viscosity. If all other geometrical factors remain the same along with the fluid considered, v1 > v2 implies Re1 > Re2. Thus, flow 2 is more likely to be laminar.