Fluid mechanics Reynolds number equation query

Join the discussion
Ask a follow-up here, or get your own question answered by working scientists, mathematicians and engineers — people, not an autocomplete.
Real named experts · corrections over time · the nuance an AI answer skips
3 replies · 8K views
smegal
Messages
7
Reaction score
0
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

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


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


The Attempt at a Solution



[tex]\rho[/tex]= (Re*[tex]\mu[/tex])/(Um*D)

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

Thanks.
 
Last edited by a moderator:
Physics news on Phys.org
kg/m^3

That is a very low density.