CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > ANSYS > ANSYS Meshing & Geometry

[Other] How to change zone type without floating point exception

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   February 1, 2021, 03:28
Default How to change zone type without floating point exception
  #1
New Member
 
Maximilian Ringel
Join Date: Jul 2020
Posts: 2
Rep Power: 0
ringel_f1 is on a distinguished road
Hello,
I am trying to model a very simple piston pump. So we have one intake channel and we have one outlet channel. There is the compression chamber where we have a moveable piston (rigid body). The intake and outlet channels are connected to the compression chamber and an the walls between these parts I have defined as components. My idea is, by making it easier to modell the intake and outtake valve, I just have to change the zone type of these connection walls. When there is the intake stroke I change the wall at the outtake channel from interiour to wall. During the compression stroke both walls form the intake and outtake channel are changed from interiour to wall. And for the exhaust stroke the wall at the outtake channel is changed from wall to interiour again. And this is where the problem occurs. So my boundary conditions are pressure inlet and outlet both the 1 bar absolute pressure. The whole simulation works until the exhaust stroke starts, where I get the message "floating point exception". This one directly comes up, when the change of the zone type was done from wall to interior... Does anybody know why this happens? Do you have an alternative way to modell this problem?


Thanks and looking forward to hearing from you!
ringel_f1 is offline   Reply With Quote

Old   February 1, 2021, 10:56
Default
  #2
Senior Member
 
Kira
Join Date: Nov 2020
Location: Canada
Posts: 297
Rep Power: 3
aero_head is on a distinguished road
Hello,

Since this is an unsteady simulation, you may need to check and modify your time-step size, what are you using currently and what numerical scheme are you using? As well, are you running your simulation in double precision?

Otherwise, there could be an issue with the mesh; what kind of mesh have you used, structured or unstructured? An example issue may be with cells that have very low aspect ratio.

Try using some of the mesh diagnostic tools, as well as looking at your volume mesh with some of the cell quality scalars.
aero_head is offline   Reply With Quote

Reply

Tags
change zone type, dynamic mesh, events, transient 3d

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
activeBaffleVelocity boundary condition ? om3ro OpenFOAM Programming & Development 10 November 16, 2020 23:26
Film cooling problem arun1994 OpenFOAM 0 October 26, 2020 09:08
Foam::error::printStack(Foam::Ostream&) at ??:? mdhfiz OpenFOAM Running, Solving & CFD 1 September 19, 2019 09:46
inlet pressure is higher than outlet pressure for fan sivakumar OpenFOAM Pre-Processing 16 December 30, 2017 14:16
Error during initialization of "rhoSimpleFoam" kornickel OpenFOAM Running, Solving & CFD 8 September 17, 2013 05:37


All times are GMT -4. The time now is 14:07.