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Low values for reaction order
Posted 25 juil. 2018, 10:29 UTC−4 Chemical Reaction Engineering, Parameters, Variables, & Functions Version 5.3a 1 Reply
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Hi,
I'm quite new to Comsol, so please excuse me if I'm asking something trivial.
I'm trying to generate a simple reactor model where DME reacts to different Hydrocarbons. But I'm only interested in the decline of DME. Here's the expressions I entered in the re-module:
re.kf_1*((re.c_DME[m^3/mol])^a_DME)[mol/m^3]
My problem is that if the exponent in DME (a_DME) _is below 0.8, the solver says that maybe a singulartiy was reached. I don't understand this behaviour, has anyone an idea about that or how to troubleshoot it?
Thanks in advance! Till
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This is only a suggestion:
Divide the concentration variable with the standard concentration C0 = 1 mol/L. Then a plain number is raised to a non-integer power. I guess that this is what you are already kind of doing as you have added [m^3/mol] after the concentration variable re.c_DME. What is the dimension of the reaction rate constant? Now it appears to be 1/s, otherwise the equation does not agree with the reaction rate.