CFD Online Logo CFD Online URL
Home > Forums > Software User Forums > Siemens

input curve BC

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

LinkBack Thread Tools Display Modes
Old   June 22, 2005, 02:41
Default input curve BC
Posts: n/a
Hi All,

I am doing exhaust manifold transient analysis with CHT.

I want to impose a BC which is time dependant. This can be achieved by tables or user subroutines. But my problem is that the input curve (obtained from expt) is highly complicated. (average outlet temperature from a IC engine comb chamber wrt time). So I can not put that in polynomial. So user subroutine option is ruled out. Now I can input that in table.

But after 92 entries in the table; star is not taking the table values. So I am not able to run the full transient analysis. Another disadvantage of table is that one can not put that in loop. Lets say I want to apply that BC in cycles over some duration. (depending on engine speed)


  Reply With Quote

Old   June 22, 2005, 04:25
Default Re: input curve BC
Jörn Beilke
Posts: n/a
Why not create some sort of table in the subroutine and interpolate the values between. You are not limited to polynoms in the subroutines.
  Reply With Quote

Old   June 22, 2005, 05:03
Default Re: input curve BC
Posts: n/a
Thanks Jörn,

But if we create table the value of the variable will remain assigned to the specific time value. But the same value for that variable will appear in next cycle for different time value. How to achieve this? One solutionn is that; I have to offset (no of cycles occured*period of cycle) time value in table to get new time value and same variable value.

Kindly guide.

  Reply With Quote


Thread Tools
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 On
Pingbacks are On
Refbacks are On

Similar Threads
Thread Thread Starter Forum Replies Last Post
hub.curve & shroud.curve Arnt-Lennard Fuglestad CFX 0 January 31, 2008 11:33
about fan curve stanta Siemens 1 June 1, 2005 10:09
How to digitised a curve Anne Main CFD Forum 12 November 18, 2004 18:40
How to generate a curve leo Siemens 1 November 19, 2002 04:52
curve list ganeshram krishnamoorthy CFX 0 April 26, 2001 11:35

All times are GMT -4. The time now is 20:50.