×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Contact US

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!

*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

Orifice flow, temperature/viscous effects

Orifice flow, temperature/viscous effects

Orifice flow, temperature/viscous effects

(OP)
I have a general question on flow through an orifice for varying temperatures/viscosities. For a given pressure drop and orifice size, intuitively I would expect a colder, more viscous oil to have less flow through the orifice than oil at temp. However from looking at the Reader-Harris/Gallagher equation for discharge coefficient, the coefficient of discharge is inversely related to the Reynolds number. Since Reynolds number is inversely related to to fluid viscosity, this would suggest to me that a more viscous fluid will have a higher discharge coefficient, resulting in more flow through an orifice for a given pressure drop relative to the less viscous fluid at temp. Which does not seem intuitive to me. Is this correct or can someone help point me to what I'm missing here? Thanks in advance.

RE: Orifice flow, temperature/viscous effects

Hello,
If that can help you:
For hydraulic oil of density 0.932 in a thin-walled nozzle the flow rate is = 0.5 ø² (dP) ^ 0.5. For a low pressure or a high viscosity I multiply the flow rate by a coefficient V.
If necessary I have the formula of the coefficient V for calculation on a computer
cordially

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! Already a Member? Login


Resources

Low-Volume Rapid Injection Molding With 3D Printed Molds
Learn methods and guidelines for using stereolithography (SLA) 3D printed molds in the injection molding process to lower costs and lead time. Discover how this hybrid manufacturing process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts. Download Now
Design for Additive Manufacturing (DfAM)
Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a part’s function at the center of their design considerations. Download Now
Taking Control of Engineering Documents
This ebook covers tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close