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Square root in equation

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Dear all

I have a simple question regarding my reaction rate formula in reaction engineering (re) module.

I am currently working with a model which includes a coupling of the reaction engineering interface, transport of diluted species, and laminar flow interfaces. My reaction rate in re is a simplified version of my original reaction rate and is as follows:

r=A*exp(-Ea/RT)*sqrt(C_O2)/C_CO

where A denotes preexponantial factor, Ea the activation energy, R the gas constant, T the temperature, c_O2 concentration of oxygen, and c_CO concentration of carbon mono oxide.

As one can see, the concentration of oxygen includes square root, and Comsol doesn't like this, so it gives an error message related to this. I tryid to compensate for the "strange unit" resulted from the square root, by determining a tailored unit for the A, so the unit for r became mol/m^3*s, indeed like COMSOL likes it. But still this didn't help.

Can anyone help me this issue? A help is appreciated.

I think the solution to it is pretty simpel, but I could not find anyone.

0 Replies Last Post 9 lug 2011, 10:35 GMT-4
COMSOL Moderator

Hello Zubeyr Yuksel

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