Which fluid is more viscous

Homework Statement

Which fluid is more viscous at moderate to high Reynolds number if used in this situation? Air or Water? The flow is incompressible and has velocity V and size L.

Homework Equations

Re = inerial forces/viscous forces = rho*V*L / mu

as Re approaches infinity, viscosity approaches zero

The Attempt at a Solution

I know that if Re is high, inertial forces dominate. Therefore, viscous forces are small.

inertial forces / Re = viscous force => wouldn't water always be more viscous assuming the same Re, V, and L is used for both air and water?

I think there is more to this problem that I am missing. Thanks for any help.

stewartcs

Homework Statement

Which fluid is more viscous at moderate to high Reynolds number if used in this situation? Air or Water? The flow is incompressible and has velocity V and size L.

Homework Equations

Re = inerial forces/viscous forces = rho*V*L / mu

as Re approaches infinity, viscosity approaches zero

The Attempt at a Solution

I know that if Re is high, inertial forces dominate. Therefore, viscous forces are small.

inertial forces / Re = viscous force => wouldn't water always be more viscous assuming the same Re, V, and L is used for both air and water?

I think there is more to this problem that I am missing. Thanks for any help.

Sounds good to me. Plus the problem states that the flow is incompressible which intuitively would rule out air.

CS