CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > FLOW-3D

three linked swimmer simulation

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   December 24, 2010, 02:03
Default three linked swimmer simulation
  #1
Member
 
s Kumar
Join Date: Jul 2009
Posts: 50
Rep Power: 16
doctsh is on a distinguished road
I am trying to do a swimming creature with three links and two joints.
I have created three 'boxes' and tried to give coupled motion in GMO model.


It swims in highly viscous fluid by flapping wings.

I have problem in giving flapping motion to the wings.

It is coupled motion. But how to give flapping effect ( beating and reversing of wings)?

Please some one help me.
Thanks in advance
Doctsh

Last edited by doctsh; December 24, 2010 at 03:23.
doctsh is offline   Reply With Quote

Old   December 27, 2010, 18:23
Default
  #2
Senior Member
 
Jeff Burnham
Join Date: Apr 2010
Posts: 204
Rep Power: 16
JBurnham is on a distinguished road
I haven't tried to do this myself, but here's one approach that may work for you (at least it seems so in theory). Note that the options described below are as they are presented in v9.4.2.

(1) define three components, all of them 'coupled-motion' GMO w/ 6 degrees of freedom (requires GMO physics package to be activated).

(2) connect the 'wings' to the 'body' using either (a) one 'compression and extension spring' and one 'torsion spring' for each wing, or (b) two 'compression and extension' springs (one at the top and one at the bottom of the wing). Search the User Manual for 'springs' to find the description of the parameters: you'll want to set the end points, spring coefficient, free length, and block length such that the connection acts as a hinge of fixed length. I think option (b) would be easier.

(3) for the two 'wings', add 'control forces/torques', using the 'define multiple forces and application points' option. Make sure that the control forces are in the 'body system', and the 'initial application point' (which will then move with the wing) is correct. Use 'tabular' data to get the sinusoidal motion you're looking for.

I'd run the simulation in a simplified fashion first, to check the motion seems reasonable, before turning the thing loose in a complex flow field. Good luck, and no promises to whether this will work! If it does, please let me know.
JBurnham 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
Solar Radiation in OpenFOAM plainstyle OpenFOAM Running, Solving & CFD 15 July 8, 2014 05:43
strange simulation error Ralf Schmidt FLUENT 2 May 4, 2007 14:02
help for Large eddy simulation Randheer Yadav FLUENT 0 July 27, 2005 17:38
transient simulation: natural convection problem? Basics CFX 3 September 25, 2002 10:42
Procedure to run unsteady simulation? STN Main CFD Forum 2 February 16, 2002 05:37


All times are GMT -4. The time now is 20:57.