How to Calculate Critical Velocity?
The formula to calculate the critical velocity of a liquid flowing through a tube is given by
Critical velocity (Vc) = K η / ρ r
where
Vc is the critical velocity
K is the Reynold’s number
\begin{array}{l}\eta\end{array}
is the coefficient of the viscosity of the liquid
r is the radius of the tube through which the liquid flows
ρ is the density of the liquid
Depending on the value of Reynold’s number, the flow type can be decided as follows:
- If K is between 0 to 2000, the flow is laminar or streamlined.
- If K is between 2000 to 3000, the flow is turbulent or unstable
- If K is above 3000, the flow is highly unstable