# temperature change + steady state

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

 January 15, 2003, 10:37 temperature change + steady state #1 John Guest   Posts: n/a Hi, Hope you can help, if I set the wall temperatures of a furnace in the boundary conditions for a steady state problem can these temperatures change with the solution or will they stay at the prescribed temperatures? Please help!! John

 January 15, 2003, 11:45 Re: temperature change + steady state #2 Eric R. Guest   Posts: n/a John, If you set the B.C. for the wall as a temperature, it will remain constant at all times. The fluid adjacent to the wall will obviously change as fluid properties permit. -Eric R.

 January 15, 2003, 12:25 Re: temperature change + steady state #3 John Guest   Posts: n/a Thanks for your reply Eric, I want to determine the heat transfer from a flame to the wall when the furnace is running at steady state conditions. So what conditions would I set at the wall so that it's temperature is not higher than the flame temperature and not too low, that it would be creating a bigger gradient than there actually is? Your help is greatly appreciated. John

 January 15, 2003, 13:34 Re: temperature change + steady state #4 Eric R. Guest   Posts: n/a John, I would assume that you are NOT looking for conduction within the wall? Because, theoretically, the surface of the wall (touching the flame) would be at the flame temperature. If you're not concerned with conduction through the wall, what I think you can do is assign a zero heat flux (0.0 W/M^2-K) to that wall (2-dimensional surface). This way, you're assuming that you'll lose no heat through the wall (perfectly insulated) and that the wall temperature will change with the local flame temperature. This should be the case b/c I model heat transfer in mixing tanks w/ helical coils and I assume a zero heat flux at the walls, but the walls themselves would have a temperature. Hope this helps. -Eric R.

 January 16, 2003, 06:23 Re: temperature change + steady state #5 John Guest   Posts: n/a Eric, That was the answer I was looking for, Thanks. As a matter of interest, I wasn't sure if conduction through the wall could be done? If I wanted to determine that, I guess I would just change the heat flux b/c?? Regards, John

 January 16, 2003, 11:41 Re: temperature change + steady state #6 Eric R. Guest   Posts: n/a John, Actually, if you want to model conduction through the wall, you would have to create the actual wall volume (ie. give the walls thickness). This would have to be meshed also. This volume would be a "solid volume" as defined in Gambit/Fluent, whereas your air/flame/etc. would be a "fluid volume." There's some option about "thickness" in the thermal conditions for a wall, but I don't exactly what this is and if it's related to conduction... Good luck! -Eric R.

 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 kriztof OpenFOAM Programming & Development 2 October 11, 2011 02:55 Miguel Baritto CFX 4 August 31, 2006 12:02 raymondyin CFX 11 May 7, 2001 06:15 Lisa Main CFD Forum 11 July 5, 2000 14:37 Jitendra Main CFD Forum 1 June 27, 2000 18:49

All times are GMT -4. The time now is 15:27.