One consequence of turbulence is mixing. Different layers of fluid flow cross over one another very easily, and get blended together. This is another kind of "transport&quo…

Question

One consequence of turbulence is mixing. Different layers of fluid flow cross over one another very easily, and get blended together. This is another kind of "transport", which lets atoms which might have started out all in one place get uniformly mixed around. Would you expect turbulent mixing to happen most easily in:

A. water
B. motor oil
C. air
D. honey

Answer 1

Basically you have to understand the Turbulence model based on the Reynolds number.

Reynolds number is defined as

`Re = (\rho v L)/(\mu)`

Where

`\rho` = Density

v = Velocity

L = Linear dimension

`\mu =` Dynamic Viscosity

This last term is the characteristic of the fluids given above for comparison.

From there we can intuit that the lower the viscosity the greater the Reynolds number and therefore there will tend to be more turbulence.

Of the four fluids presented we have to

Water
`\rightarrow 8.90*10^(-4) Pa\cdot s`

Motor oil
`\rightarrow` From 0.085 to
`0.9 Pa\cdot s`

Air
`\righarrow 1.81*10^(-5) Pa\cdot s`

Honey
`\rightarrow 10 Pa\cdot s`

The minimum value is for the Air. Therefore there you will expect turbulent mixing to happen most easily. Correct Answer is C.