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Old   July 11, 2015, 12:02
Default using dimensional variables as dimentionless
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hani mortezaee
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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
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Old   July 11, 2015, 12:08
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for information , im modeling the energy deposition of proton beam from cyclotron in the compressed N2 gas ,
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Old   July 12, 2015, 06:02
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Glenn Horrocks
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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?
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Old   July 12, 2015, 07:22
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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'."
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Old   July 12, 2015, 07:27
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my bad , it just needed parenthesis , , so stupid ,
thankyou Glenn
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