# DG method, very small time step

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

 April 17, 2013, 05:34 DG method, very small time step #1 New Member   Join Date: Mar 2013 Posts: 14 Rep Power: 6 When I apply the Discontinous Galerkin method on the KdV equation, the time step can only take very small number, like 0.0001. Can anyone tell me it is normal or not. Thanks !

April 17, 2013, 05:38
#2
Senior Member

cfdnewbie
Join Date: Mar 2010
Posts: 557
Rep Power: 13
Quote:
 Originally Posted by Wenjun When I apply the Discontinous Galerkin method on the KdV equation, the time step can only take very small number, like 0.0001. Can anyone tell me it is normal or not. Thanks !

yeah, DG has a timestep of 1/(2n+1), where n is the ansatz degree. Which order is your ansatz?

April 17, 2013, 05:43
#3
New Member

Join Date: Mar 2013
Posts: 14
Rep Power: 6
Quote:
 Originally Posted by cfdnewbie yeah, DG has a timestep of 1/(2n+1), where n is the ansatz degree. Which order is your ansatz?
I am a new guy of DG. I use the second-order element and the third-order TVD Runge-Kutta method. I set dx = 0.1, how should I choose the time step?

 Tags dg method, time step size

 Thread Tools Display Modes Linear Mode

 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 OffTrackbacks are On Pingbacks are On Refbacks are On Forum Rules

 Similar Threads Thread Thread Starter Forum Replies Last Post CKH OpenFOAM Running, Solving & CFD 12 March 21, 2016 14:05 karasa03 OpenFOAM 7 December 12, 2013 04:41 sharonyue OpenFOAM Running, Solving & CFD 6 June 10, 2013 09:34 Heroic OpenFOAM Running, Solving & CFD 26 December 17, 2012 04:34 bookie56 OpenFOAM Installation 8 August 13, 2011 04:03

All times are GMT -4. The time now is 11:46.