CFD Online Logo CFD Online URL
Home > Forums > Software User Forums > FloEFD, FloWorks & FloTHERM

Internal Fans in External Analysis

Register Blogs Members List Search Today's Posts Mark Forums Read

LinkBack Thread Tools Search this Thread Display Modes
Old   June 14, 2017, 14:16
Default Internal Fans in External Analysis
New Member
Join Date: Jun 2017
Posts: 3
Rep Power: 7
jjnud is on a distinguished road

I'm trying to better understand how fans work in FloEFD. I have placed a fan inside of a box, and have qualified it as an internal fan with fluid entering on one side, and exiting on the other.

As I run the solver, I get a warning; 'Mass Flow is out of Fan curve's range.' When the solver finishes, and I try and view the flow trajectory, I get a very low fluid velocity through the fan (0.5 m/s or so).

Does anyone know what this error means, how I can remedy it, and how I can get a larger airflow through the fan?

jjnud is offline   Reply With Quote

Old   June 26, 2017, 15:24
Senior Member
Join Date: Jul 2009
Posts: 616
Rep Power: 22
Boris_M will become famous soon enough
Hi Joseph,

You can always go into the FloEFD help in the software and search for the error message. In this case it gives this information in the help:

"Mass flow is out of fan curve's range." - It means that the calculated mass flow rate value is out of the specified fan curve's range. This may happen when the specified mass (or volume) flow rate values do not cover the full range that the real fan operates. It is recommended to inspect the fan definition in Engineering Database and the project’s fan condition for possible errors. See Fans - Basic Information for details.

I cannot really tell what you did in your model so it is hard to tell what is wrong.

As for how fans work, this should help you:

I think the definition external inlet fan or external outlet fan etc. is self-explanatory.
Fans work just like they do in reality, they have a fan curve defined just like you can find in their data in the datasheet. The boundary condition checks on the pressure between the two sides of the fan which will be the delta Pressure in the curve and the flow rate applied is then taken out of the fan curve. Any flow pattern out of the fan depends on the other information in the fan database such as hub diameter RPM etc.
Again, you can find more information in the help. The fastest way to get to the right topic is either you click on help in the engineering database or in the fan curve boundary condition which will get you closer to the needed topic.

I hope this helps,
Boris_M is offline   Reply With Quote

Old   June 27, 2017, 18:18
New Member
Join Date: Jun 2017
Posts: 3
Rep Power: 7
jjnud is on a distinguished road
Thanks for taking the time to help me out, Boris. I really appreciate it.
jjnud is offline   Reply With Quote


airflow simulation, cfd, fans, floefd, floefd pro 9

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On

Similar Threads
Thread Thread Starter Forum Replies Last Post
ANSYS WORKBENCH Transfer result of one analysis to a new analysis as preload ingjuanm90 ANSYS 0 July 26, 2016 15:04
boundary conditions for analysis of a prop (External) jpc Autodesk Simulation CFD 11 January 16, 2013 16:10
difrrence betwin external and internal flow hmasenger CFX 1 January 1, 2013 18:51
flow modeling and incompressible analysis of internal flow of effervescent injector umar959 FLUENT 0 November 15, 2011 04:32
internal / external flow schemes jay jay okacha Main CFD Forum 4 April 1, 2003 11:56

All times are GMT -4. The time now is 05:09.