×
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!

*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

FLOWORKS Accuracy

FLOWORKS Accuracy

FLOWORKS Accuracy

(OP)
To All,

I'm going to post this on Solidworks forum as well but I figured I should try here too.
We recently purchased Floworks and are using it to thermally model an electronics project. Before we start using it for any projections on this design, we're testing its accuracy on small experiments.

Right now I've got a 3 Ω resistor burning 3 Watts attached to a heatsink. I've entered heat generation, thermal resistance (measured and calculated), ambient air conditions etc.
I'm quite sure I have all of the initial conditions as close to reality as possible.
Unfortunately I cannot get the results to get any closer than 10°C below what I am physically measuring (Calc = 40°C, Meas = 30°C).

Have any of you guys gotten floworks to produce highly accurate results (i.e. ±2.5°C) or is it always off or is there some major variable that is easy to miss that would influence the results?

Thanks in advance - Bram
Replies continue below

Recommended for you

RE: FLOWORKS Accuracy

Hello:

The problem sounds interesting. We have had good experience in correlation of the kind stated, with SolidWorks Flow Simulation. Maybe you can send me a model that I can investigate and provide feedback,

Natarajan Ramamoorthy
Design Engineering Consultant
www.egsindia.com

RE: FLOWORKS Accuracy

(OP)
So I've been doing some experimentation and I've gotten much closer to real results.

Playing around with contact resistance (as measured), air-flow (as assumed), and turning on things like gravity and radiation calculations have all contributed to more accurate results.

Unfortunately the two most influential attributes are the contact resistance and air flow. Contact resistance must be measured first since nearly all real-life junctions are not found in tables, and air flow which is assumed because it is difficult to accurately measure CFM at the inlet.

I can play with these numbers and get drastically different results which isn't boasting well for the software providing a "max-temp."

It does however, tell me where the hot spots are and which configurations are relatively better which is a strong plus.

If anyone's figured out how to utilize the software further I would be glad to hear about it.

- Bram

RE: FLOWORKS Accuracy

RE: variations in contact resistance (thermal and electrical)

I guess I'm not surprised since computer processors are (and must be) mounted with fancy thermal grease, and Cadillacs' and other GM cars' accessories were plagued with connector issues a decade or so back.

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



News


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