Question

In fully developed laminar flow in a circular pipe, if the velocity at midway between the wall surface and the centerline is measured to be 6 m/s, then the velocity at the centre of pipe is

• A. $6m/s$
• B. $4m/s$
• C. $8m/s$
• D. $10m/s$

Answer 1

The correct option is C $8m/s$

Velocity at any point in laminar flow inside a circular pipe is given as

$V=V_{max}(1-\frac{r^2}{R^2})\to \left(1\right)$

$V_{max}=centrelinevelocity=maximumvelocity$

$Givenatr=R/2,V=6m/s$

$\therefore$ $Using\left(1\right)$
$6=V_{max}(1-\frac{(R/2{)}^2}{R^2})$

$\Rightarrow V_{max}=8m/s$