- #1
cps.13
- 40
- 1
Homework Statement
The questions is:
For many liquids the viscosity is strongly dependent on temperature. Use the table below to estimate the required maximum temperature of crude oil to flow at a rate of 4Kg s-1 through a 0.3 metre diameter pipe whilst maintaining a laminar flow.
In the table it has in the rows.
Crude Oil (sg = 0.885)
Viscosity (x10-3 Nsm-2)
Does anybody know what the (sg =0.855) means? There is no explanation of this.
2. Reynolds equation for finding laminar flow
Reynolds # = (density)(velocity)(pipe diameter) / (viscosity)
density = 860kg/3
velocity = ??
pipe diameter = 0.3m
viscosity = 0.016 (others are given in the table but I cannot paste that in here, for now assume 0.016)
The Attempt at a Solution
[/B]
I think I know how to do it, what I am struggling with is converting my 4Kg s-1 to a use able value to get my velocity.
I am trying...
flow rate = area x velocity
therefore
velocity = flow rate/area
velocity = 4/(0.15xπ2) = 56.588
this then goes into my reynolds number equation
(860)(56.588)(0.30) / 0.016 = 912481.5
this answer is far too high as it should be less than 2000!
I'm guessing there is something wrong with my conversion from flow rate to velocity but cannot figure out what I'm doing wrong. Think it is do with the Kg s-1. Needs to be converted first but not sure how!
Thanks