×
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

ANSYS: transient thermal analysis--phase change question

ANSYS: transient thermal analysis--phase change question

ANSYS: transient thermal analysis--phase change question

(OP)
Hi everyone:

Is anyone familiar with phase change calculations in ANSYS?  I would really appreciate some conceptual help.

I have results from separate thermodynamic calculations of (1) solidification and (2) heating up/melting.  I now want to incorporate the thermo results in ANSYS (command line) to find out how the solidifying substance affects its surroundings (i.e., how the surrounding container heats up and melts; length and time scales).  I am using example 3.93/3.94 (Example of a transient thermal analysis/Commands for building and solving the model) as a guide.

Two questions:

1)  In the ANSYS example, only the solidifying stuff changes phase.  In my calculations, the solidifying stuff AND the container (which may melt) change phase.  Can I define two MPDATA,ENTH tables in a single phase change calculation, one for the container and one for the solidifying stuff?

2) Here's the conceptual issue: My separate thermo calculations yield NEGATIVE enthalpies of formation.  Is this OK?  Physically, I know it's OK, but is it OK in ANSYS to enter negative enthalpy values?  Can I simply plug these negative values for (1) the container and (2) the solidifying stuff into the MPDATA tables?  I can't simply remove the signs because then I will get enthalpy versus temperature curves that are negative and ANSYS doesn't allow this.  These are enthalpies of formation, not flow values.  

Thanks a lot for any help.     

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