×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Calculating Fluid Flow Rate Through Orifice
2

Calculating Fluid Flow Rate Through Orifice

Calculating Fluid Flow Rate Through Orifice

(OP)
I am trying to replicate the result of an on-line orifice plate calculator but am apparently overlooking a key point.  Can anyone spot my error?

I am using the equation: flow rate = flow coefficient*orifice area*sqrt(2(deltaP)/density)for a fluid.

where flow coefficient = discharge coefficient / sqrt(1-(d2/d1)^4)

inner pipe diameter (d1) = 0.837 in
orifice diameter (d2) = 0.579 in
kinematic viscosity @200F = 1.32 cSt
deltaP = 1 psi
specific gravity@ 200F = 0.9556
discharge coefficient = 0.63

flow coefficient = 0.63/(sqrt(1-0.579/0.837)^4) = 0.718

flow rate = (0.718)*(pi*(0.579)^2/4)*sqrt(2*1/(0.036111/386))

The calculator shows a flow rate of 28.5 cu in/s while my manual calculation shows 47.6 cu in/s. Where is my error?  Even though the dimensional analysis works out, I wonder why the viscosity does not play a part in this equation?
 

RE: Calculating Fluid Flow Rate Through Orifice

Run your numbers again.  I got 27.6 cu in/s using your exact numbers.  Plus you left out s.g. in your calculations.  With s.g. I got 28.3 cu in/s.

Good luck,
Latexman

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources