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Units problem

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Hello,
I am trying to set up a model about endothermic reaction in a tube reactor. Hydrogen is produced in the process of reaction. When I used -k*c_A*deltaH to express heating source, the program regarded the unit was wrong. Also, when I used 3*k*c_A to express the production of hydrogen, the progran again regarded the unit was wrong. Can anybody explain why?
Thank you very much.

2 Replies Last Post 27.10.2011, 14:00 GMT-4
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago 27.10.2011, 13:24 GMT-4
Hi

I suppose it all depends what are the units of your variables and where you used them. I believe you should dump an image at least with some more details to give us a better clue. many fields in COMSOL are "per element dx*dy*dz) hence the demand for density units

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Good luck
Ivar
Hi I suppose it all depends what are the units of your variables and where you used them. I believe you should dump an image at least with some more details to give us a better clue. many fields in COMSOL are "per element dx*dy*dz) hence the demand for density units -- Good luck Ivar

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Posted: 1 decade ago 27.10.2011, 14:00 GMT-4
Hi Ivar,
Thank you for the quick response. I have solved the problem.
Best regards,
Xuxian
Hi Ivar, Thank you for the quick response. I have solved the problem. Best regards, Xuxian

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