CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > CONVERGE

Alignment error in engine simulation

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

Like Tree1Likes
  • 1 Post By ksrivast

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   June 27, 2018, 08:11
Post Alignment error in engine simulation
  #1
New Member
 
Sangeeth Sanal
Join Date: Jul 2015
Posts: 3
Rep Power: 10
sangeeth is on a distinguished road
1850 WARNING:
there may be an alignment error.
The maximum dot product of the motion vector with a non-moving triangle's normal vector is 1.166965e-03.
For properly aligned moving surfaces, this dot_product should be less than 5.0e-4


1851 WARNING: The boundary type that appears to not be aligned is WALL, and it is attached to boundary 1, which is moving.

The triangle of maximum alignment error is centered at -6.137263e-03 4.243868e-02 -3.186973e-02



Hi

What can be a solution for this error in engine simulation. I tried to project vertices from the piston to head but I cant find any alignment error. I can run the simulation with this error/warning, but when I turn on monitor points the simulation just crashes.
sangeeth is offline   Reply With Quote

Old   June 29, 2018, 18:55
Default
  #2
New Member
 
Chaitanya Ghodke
Join Date: May 2017
Location: Convergent Science, Madison WI
Posts: 29
Rep Power: 8
chaighodke is on a distinguished road
Can you please let me know what is boundary 1? This error is typically a geometry related issue. I suggest make sure that you are using correct valve axes. Can you please check that.
__________________
---------------------------------------------​​
Chaitanya D. Ghodke, Ph.D
.
Senior Research engineer
Convergent Science Inc.
---------------------------------------------
chaighodke is offline   Reply With Quote

Old   June 30, 2018, 09:55
Default
  #3
New Member
 
Sangeeth Sanal
Join Date: Jul 2015
Posts: 3
Rep Power: 10
sangeeth is on a distinguished road
Hi Chaitanya


Thank you for the reply. The error was geometry related. The geometry has just a piston and head. I was able to rectify that by projecting the curve from piston to head.
sangeeth is offline   Reply With Quote

Old   February 4, 2024, 02:29
Default Alignment error in engine simulation
  #4
New Member
 
ibrahim
Join Date: Jun 2018
Posts: 5
Rep Power: 7
ibrahimtas is on a distinguished road
Hello,
The problem you have encountered is certainly geometry related, but I have not tried rebuilding the methods suggested to solve this problem (such as rebuilding the cylinder liner with the loft command) and unfortunately it did not work.

If you were able to solve this problem, can you describe in detail how you did it?
ibrahimtas is offline   Reply With Quote

Old   February 9, 2024, 18:42
Default
  #5
Senior Member
 
ksrivast's Avatar
 
Kislaya Srivastava
Join Date: Sep 2017
Location: Convergent Science, Northville MI
Posts: 160
Rep Power: 8
ksrivast is on a distinguished road
Hello Ibrahim,

Cylindrical liners must be rebuilt with the Create > Triangle > Sweep edges option, not the Loft edges option. This will ensure liner triangles are perfectly cylindrical along the piston motion axis provided (Sweep direction). Starting from the piston edge, sweep a single set of liner triangles over a sweep amount slightly greater than your stroke. Connect the open edge of the swept triangles with the open edge on the head with the Loft edges option to close the geometry.

Pay attention to the boundary IDs in the warning messages. If the IDs correspond to the valve boundaries, the same needs to be done for valve stem boundaries along the valve motion direction.

We recommended you take a look at our Piston and Valve Setup training session, available at our downloads page. This session as part of our CONVERGE for IC Engines course guides users on how to construct moving/deforming boundaries.

Sincerely,
ibrahimtas likes this.
__________________
Kislaya Srivastava
Senior Research Engineer | Applications
CONVERGECFD
ksrivast is offline   Reply With Quote

Old   February 10, 2024, 03:16
Default
  #6
New Member
 
ibrahim
Join Date: Jun 2018
Posts: 5
Rep Power: 7
ibrahimtas is on a distinguished road
Thank you very much for your answer, Kislaya.


I would also have one more question. I am currently using Converge version 3.2. But the license of Converge software belongs to a friend of mine. I access the download and training center with his account. However, I would like to have an account of my own. I registered to the download center, but it is not active, how can I resolve this issue.
ibrahimtas is offline   Reply With Quote

Old   February 10, 2024, 03:20
Default
  #7
New Member
 
ibrahim
Join Date: Jun 2018
Posts: 5
Rep Power: 7
ibrahimtas is on a distinguished road
Thank you very much for your guidance.

This time when I did this problem as you stated, it worked. However, I do not have access to the download center you mentioned. I have done the registration process, I am waiting for it to be activated for access, but access has not been activated. Can you support me on this issue?

Sincerely regards
ibrahimtas is offline   Reply With Quote

Reply

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
Internal combustion engine simulation MichaelC CFX 5 August 13, 2023 07:03
Tutorial files on SI engine simulation using ANSYS FLUENT Upendra FLUENT 0 September 27, 2012 12:57
diesel engine combustion simulation kebi112358 OpenFOAM 4 September 25, 2012 14:16
Engine simulation (seeking help with method to use) Geoff Rathbun Main CFD Forum 4 April 13, 1999 15:19
Question concerning about the flow simulation of a fan in an engine room. ghlee Main CFD Forum 3 October 21, 1998 08:05


All times are GMT -4. The time now is 08:53.