Question

Which of the following is not a dimensionless parameter?
1) Reynolds number
2) Friction factor
3) Kinematic viscosity
4) Pressure coefficient

Answer 1

I don't knowI don't knowI don't know

Answer 2

The correct answer is option (3) Kinematic viscosity.

A dimensionless quantity means the quantity that can be represented by M°L°T°. Here only kinematic viscosity is not dimensionless as it has dimension L2 T-1.

To understand it, first let us know that viscosity is the resistance offered by a fluid to flow.

We commonly work with kinematic viscosity, which is associated with the flow of a fluid.

Kinematic viscosity is defined as the ratio of viscosity to the density of fluid.  The SI unit is m²/sec. Hence, the dimensions are L2 T-1.