# using dimensional variables as dimentionless

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

 July 11, 2015, 12:02 using dimensional variables as dimentionless #1 New Member   hani mortezaee Join Date: Sep 2014 Posts: 22 Rep Power: 3 hi everyone , im trying to define an expression for my subdomain energy source that is function of coordinates but i cant because coordinates like x,y or xGlobal,yGlobal have [m] dimension , How can i fix this problem , i tried to do this ( x/1[m] ) but it didnt work , please help me

 July 11, 2015, 12:08 #2 New Member   hani mortezaee Join Date: Sep 2014 Posts: 22 Rep Power: 3 for information , im modeling the energy deposition of proton beam from cyclotron in the compressed N2 gas ,

 July 12, 2015, 06:02 #3 Super Moderator   Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 11,045 Rep Power: 86 Why is having the x,y,z variables in metres a problem? You can change to other units systems if you like. The expression x/1[m] will return a unitless value - so what did not work about it?

 July 12, 2015, 07:22 #4 New Member   hani mortezaee Join Date: Sep 2014 Posts: 22 Rep Power: 3 no it didnt return unitless value , for example if this is my expression " (x/1[m])^2 [kg m^2 s^-3] " the error given is " Bad expression value 'energy' detected in parameter 'Total Source' in object '/FLOW:Flow Analysis 1/DOMAINefault Domain/SUBDOMAIN:Subdomain 1/SOURCES/EQUATION SOURCE:energy'. CEL error: Exponent must be dimensionless to right of '^' operator at position 9. Actual dimensions: 'kg m^2 s^-3'."

 July 12, 2015, 07:27 #5 New Member   hani mortezaee Join Date: Sep 2014 Posts: 22 Rep Power: 3 my bad , it just needed parenthesis , , so stupid , thankyou Glenn

 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 Antech ParaView 0 June 4, 2015 02:38 Badi CFX 1 July 25, 2013 08:01 N.P CFX 5 December 1, 2011 08:47 rassilon OpenFOAM Installation 2 February 16, 2010 21:54 Eugene Phoenics 9 November 2, 2001 23:00

All times are GMT -4. The time now is 09:19.