CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > Siemens > STAR-CCM+

Open Fan Geometry Boundary Conditions External Aerodynamics

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   April 23, 2020, 15:54
Default Open Fan Geometry Boundary Conditions External Aerodynamics
  #1
New Member
 
Join Date: Apr 2020
Posts: 8
Rep Power: 5
Jordan1997 is on a distinguished road
I hope I've posted this thread in the correct place, apologies if not. I am currently using star-ccm+ to simulate a fixed wing UAV with tilting ducted fans at its wingtips. (Please see image to see geometry and mesh)

I'm trying to run a preliminary sim to obtain a drag value for my aircraft at cruise conditions to then identify my thrust requirement, but unsure what to set as my boundary conditions for the inlet and outlet faces of my fan. I essentially want an open duct. I have to keep these boundaries as my geometry fails to subtract as it will not be closed and manifold.

I have each face set as a freestream boundary with values in line with my farfield freestream boundary. Does this sound correct to simulate an open duct? My solution looks a bit unstable and I'm pretty confident in my mesh.
Attached Images
File Type: jpg Capture.jpg (141.4 KB, 16 views)
Jordan1997 is offline   Reply With Quote

Old   April 25, 2020, 03:18
Default
  #2
Senior Member
 
Ping
Join Date: Mar 2009
Posts: 556
Rep Power: 20
ping is on a distinguished road
free-stream should not be used on the fan so I would be using maybe a mass flow inlet on both ends of the fan since it can be both as an inlet and an outlet and you then know that mass will be conserved if you set the same value
ping is offline   Reply With Quote

Old   April 26, 2020, 05:31
Default
  #3
New Member
 
Join Date: Apr 2020
Posts: 8
Rep Power: 5
Jordan1997 is on a distinguished road
Calculated a mass flow rate and set both faces to this which has helped my solutions converge and simulate better what I need, thanks for the help!
Jordan1997 is offline   Reply With Quote

Reply

Tags
boundary conditions, ducted fan, external aerodynamics

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
[OpenFOAM.org] Error creating ParaView-4.1.0 OpenFOAM 2.3.0 tlcoons OpenFOAM Installation 13 April 20, 2016 18:34
Problem in setting Boundary Condition Madhatter92 CFX 12 January 12, 2016 05:39
Trouble compiling utilities using source-built OpenFOAM Artur OpenFOAM Programming & Development 14 October 29, 2013 11:59
Low Mixing time Problem Mavier CFX 5 April 29, 2013 01:00
Error finding variable "THERMX" sunilpatil CFX 8 April 26, 2013 08:00


All times are GMT -4. The time now is 06:26.