A fluid of density ' $\rho$ ' and viscosity ' $\eta$ ' is flowing through a pipe of diameter ' $d$ ', with a…

A fluid of density ' $\rho$ ' and viscosity ' $\eta$ ' is flowing through a pipe of diameter ' $d$ ', with a velocity ' $v$ '. Reynold number is
  1. $\frac{2 d \rho v}{\eta}$
  2. $\frac{\mathrm{d} \rho \mathrm{v}}{\eta}$
  3. $\frac{d \rho v}{\eta^2}$
  4. $\frac{2 \eta \mathrm{dv}}{\rho}$

Solution

The Reynolds number is the ratio of inertial forces to viscous forces within a fluid subjected to relative internal movement due to different fluid velocities. A region where these forces change behavior is known as a boundary layer, such as the bounding surface in the interior of a pipe. $\mathrm{R}_{\mathrm{e}}=\frac{\mathrm{\rho} V \mathrm{D}}{\mu}$ Where $\rho=\text { density of the fluid }$ $\mathrm{V}=\text { velocity in } \mathrm{m} / \mathrm{s}$ D = Diameter $\mu=$ Dynamic Viscosity

Asked in: MHT CET 2023 (09 May Shift 2)

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