Fluid mechanics Reynolds number equation query

[smegal]

1.I have been asked to:

Calculate the density of a fluid if a ctitical velocity of 2m/s at Re=2000 in a pipe of bore 90mm at a dynamic viscosity oc 0.09cP

I have calcualted the variables to SI units and found

\rho=?
Um (V) =2m/s
D=0.09m
\mu=0.09X10^-3


I am rearranging this formula
[b]http://www.rpgroup.caltech.edu/%7Enatsirt/aph162/webpages/F2WP2/reynoldsNumberFormula.png


3. The attempt at a solution

\rho= (Re*\mu)/(Um*D)

I keep getting 1 as the answer for the density. Have I converted something to SI units incorrectly?

Thanks.

[diazona]

1 what? Units please :biggrin:

Also, why do you suspect 1 is wrong?

[smegal]

kg/m^3

That is a very low density.

[Redbelly98]

kg/m^3

That is a very low density.

That's comparable to air, which is 1.2 kg/m^3 under normal conditions (20 C, 1 atm)