Chapter 14, Problem 1P

To determine

The flow which is likely meant to be turbulent and explain the reason.

Explanation of Solution

The flow which have higher Reynolds number is more likely to be turbulent. Disorders in the velocity fluctuations and more disordered motion characterizes the turbulent flow. The ratio of the inertial force to the viscous force in the fluid is called Reynolds number. Expression for the Reynolds number is given by,

    $\mathrm{Re}=\frac{V\cdot D}{v}$

Here, $V$ is the flow velocity, $D$ is the characteristic length of the geometry, $\mu$ is the kinetic viscosity.

According to the above equation, kinematic viscosity is inversely dependent to the Reynolds number for a liquid having constant velocity and diameter. The higher kinematic viscosity of the air shows the lesser Reynolds number. Thus water flow is more likely to be turbulent.