# time step!!!

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

 February 2, 2010, 12:09 time step!!! #1 New Member   Vijesh Joshi Join Date: Mar 2009 Posts: 10 Rep Power: 9 Hello friends, I am solving 1-d transient heat conduction equation by FVM. I am trying to analyze "heat flow through a very thin sheet of steel". Sheet thickness is 0.5mm. q on one side is given AND IS VERYING WITH TIME. Becoz of higher K (43 W/m-K) value of steel, I am in need to use very small time step. I used dy=0.5mm/3=0.167mm=1.67e-4 m.. dt=0.01sec ... But results are not converged.. I am using fully implicit scheme to solve the transient cond eq... Do I need to worry abt Courant number?? Is there any other way that I can solve this problem with higher time step???

 February 2, 2010, 23:22 #2 Senior Member   Julien de Charentenay Join Date: Jun 2009 Location: Australia Posts: 230 Rep Power: 10 Hi, Can you clarify what do you mean by q (which I take as a heat flux at one end) is "VERYING WITH TIME"? I understand the need for very small time-step as the plate is both thin and has a high thermal diffusivity. But considering that you are using an implicit integration scheme (and we are talking about diffusion only), I would think that the time-step should relate to the time variation of "q". The courant number is a limitation related to the convection term (Co = Dt * U/ Delta) and is not relevant to a diffusion only problem. Regards, Julien

 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 msrinath80 OpenFOAM Running, Solving & CFD 18 March 3, 2015 06:36 amos FLUENT 0 December 1, 2009 04:31 meangreen Main CFD Forum 5 August 27, 2009 12:32 ReeKo CFX 11 October 8, 2008 17:57 Le FLUENT 2 July 20, 2006 22:00

All times are GMT -4. The time now is 16:42.