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

Errors Using SDOF with Object of Small Mass (10^-12 kg)

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   June 26, 2020, 12:55
Default Errors Using SDOF with Object of Small Mass (10^-12 kg)
  #1
New Member
 
Join Date: Jun 2020
Posts: 8
Rep Power: 6
aCamb27 is on a distinguished road
I am trying to use the 6-DOF solver on an object with very small mass (on the order of 10^-12 kg), but am getting unreasonably large displacements and velocities of the object compared to experimental values. I have tried reducing the time step (down to 10^-10 sec/step), but still this problem persists. Looking at the Ansys Theory guide, I imagine this is occurring due to the fact that Ansys calculates acceleration (and therefore velocity) by summing forces over an object and dividing by the mass (which here is very small). I am wondering if anyone has come across similar problems using very small masses with the SDOF solver, and if so, how they have overcome them.


On a related note, does anyone know what forces Ansys sums for the SDOF solver, specifically for laminar flow in a non-Newtonian fluid? Perhaps a force relevant for my simulation is not accounted for in what Ansys solves, and as a result I could externally add that force onto the object in a UDF to generate the correct net force profile.


Thank you for the help!
aCamb27 is offline   Reply With Quote

Reply

Tags
6dof, error, fluent, sdof

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
[solidMechanics] Support thread for "Solid Mechanics Solvers added to OpenFOAM Extend" bigphil OpenFOAM CC Toolkits for Fluid-Structure Interaction 686 December 22, 2022 09:10
Floating point exception error lpz_michele OpenFOAM Running, Solving & CFD 53 October 19, 2015 02:50
[OpenFOAM] Annoying issue of automatic "Rescale to Data Range " with paraFoam/paraview 3.12 keepfit ParaView 60 September 18, 2013 03:23
Upgraded from Karmic Koala 9.10 to Lucid Lynx10.04.3 bookie56 OpenFOAM Installation 8 August 13, 2011 04:03
Compilation error OF1.5-dev on Suse10.3 darenyang OpenFOAM Installation 0 April 29, 2009 04:55


All times are GMT -4. The time now is 18:16.