×
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

Cp and Visc. vary with Temp & Press?

Cp and Visc. vary with Temp & Press?

Cp and Visc. vary with Temp & Press?

(OP)
I'm looking at aeration headers delivering compressed air from blowers.  Thanks to those in a previous thread who helped me debug head loss calcs.

Anyway, today I'm looking at average temperature of air in the pipe.  Since the pipe is uninsulated, I'm iterating heat transfer equations in order to predict heat loss and thus temperature at the end of the pipe run.  These calcs rely on accurate gas properties.  I know that air density can be approximated at temp & press using the ideal gas relationship.

---> However I'm not so sure about Specific Heat and Kinematic Viscosity.  I've checked MERM and some online references but I'm not sure how to get *actual* Cp and visc. since the tabulated values normally reference a range of temps at 'standard' pressure.  Whereas our average pressure is about 9 psig.  Any ideas on this?

RE: Cp and Visc. vary with Temp & Press?


Perry's Chemical Engineering Manual VI Ed, table 3-212 gives the properties of air you are after as function of pressure and temperature.

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