Inlet velocity as a function of time. Transient analysis.

Elgaard · December 11, 2012, 07:58

Hello,

Does anybody know if it is possible to setup an inlet boundary with userdefined velocity as a function of time.

What i would like to do is set the velocity to 0m/s for 0->1s and then 10m/s for 1->10s.

Is it possible to set up a table, or in any other way define the velocity in a more advanced way?

/Elgaard

Lance · December 11, 2012, 08:01

Your example can easily be solved using an expression with step functions. For more advanced profiles see http://www.edr.no/blogg/ansys_blogge...nsient_profile (or search this forum...)

Elgaard · December 11, 2012, 09:03

Thank you. I am quite new to CFX, but this helped a lot. Found a manual for the CEL language, and got it to work.

Manual: http://hikwww2.fzk.de/hik/orga/hlr/A...xpres_lang.pdf

Expression: step(t*1[s^-1]-1)*10[m s^-1]

/Elgaard

Lance · December 12, 2012, 02:36

The manuals come with the installation, usually located at:
C:\Program Files\ANSYS Inc\v140\commonfiles\help\en-us\pdf
or by pressing F1 inside CFX.

December 11, 2012, 07:58	Inlet velocity as a function of time. Transient analysis.	#1
Elgaard New Member Christian Elgård Clausen Join Date: Dec 2012 Location: Copenhagen, Denmark Posts: 7 Rep Power: 13	Hello, Does anybody know if it is possible to setup an inlet boundary with userdefined velocity as a function of time. What i would like to do is set the velocity to 0m/s for 0->1s and then 10m/s for 1->10s. Is it possible to set up a table, or in any other way define the velocity in a more advanced way? /Elgaard

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December 11, 2012, 08:01		#2
Lance Senior Member Lance Join Date: Mar 2009 Posts: 669 Rep Power: 22	Your example can easily be solved using an expression with step functions. For more advanced profiles see http://www.edr.no/blogg/ansys_blogge...nsient_profile (or search this forum...)

December 11, 2012, 09:03		#3
Elgaard New Member Christian Elgård Clausen Join Date: Dec 2012 Location: Copenhagen, Denmark Posts: 7 Rep Power: 13	Thank you. I am quite new to CFX, but this helped a lot. Found a manual for the CEL language, and got it to work. Manual: http://hikwww2.fzk.de/hik/orga/hlr/A...xpres_lang.pdf Expression: step(t1[s^-1]-1)10[m s^-1] /Elgaard

December 12, 2012, 02:36		#4
Lance Senior Member Lance Join Date: Mar 2009 Posts: 669 Rep Power: 22	The manuals come with the installation, usually located at: C:\Program Files\ANSYS Inc\v140\commonfiles\help\en-us\pdf or by pressing F1 inside CFX.