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2D Diffusion with enzyme kinetics using transport of dilute species

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I have the Comsol multiphysics 6.0 academic class kit license.

I am trying to model for 2d diffusion of pepsin with Michaelis menton chem kinetics using 'transport of diluted species' interface and 'time dependent' study (see image 3). I have defined the constants (vmax, km) in the 'global definititions parameters1' section to be used as part of the MM equation (see image 1). However when I add the 'reactions' option to the model, it only lets me input a single reaction rate Rc (see image 2). How can I can change this predefined equation to input the MM term - vmax x c / (km + c) and call the predefined constants from global definitions? I dont have access to the chemical engineering module on my current license, so hoping you can help. Thanks!



1 Reply Last Post Mar 7, 2022, 3:32 p.m. EST
Jeff Hiller COMSOL Employee

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Posted: 2 years ago Mar 7, 2022, 3:32 p.m. EST
Updated: 2 years ago Mar 7, 2022, 4:49 p.m. EST

Hello Maany,

If I understand you correctly, you have several species for which you want to solve simultaneously.

With the Chemical Reaction Engineering Module or any of the other products that include the "add-on for multiple species user interface" (see screenshot attached), it is true that you would be able to directly specify the number of species you need in a single tds physics interface. Without any of those products, you can instead add one tds physics interface per species into your model. It's not as elegant, but it works.

Best,

Jeff

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Jeff Hiller
Hello Maany, If I understand you correctly, you have several species for which you want to solve simultaneously. With the Chemical Reaction Engineering Module or any of the other products that include the "add-on for multiple species user interface" (see screenshot attached), it is true that you would be able to directly specify the number of species you need in a single tds physics interface. Without any of those products, you can instead add one tds physics interface per species into your model. It's not as elegant, but it works. Best, Jeff

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