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Syngas Combustion in a Round-Jet Burner

Posted Feb 9, 2015, 6:18 p.m. EST Heat Transfer & Phase Change, Materials, Modeling Tools & Definitions, Parameters, Variables, & Functions Version 4.4 1 Reply

Justin Pommerenck
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I appreciate the help and the terrific model in the COMSOL gallery(Model ID: 14881). I have worked the example and need to make altercations in the problem to fit my modeling need. Everything is very clearly described in the accompanying file (.pdf) except I need a reference for the portion of the model that explains the heat source1, API or where those terms are located in the COMSOL introduction guide?

Under heat source1 is found this input for q:

-(dH_R1*rspf.rEDC_treac1+dH_R2*rspf.rEDC_treac2)

I infer that (rspf) is the model physics reacting flow (rspf) and that the .r is refering to the geometry of the problem (the radial position). I do not know what EDC means; _t means (time for the t). I assume reac1 and reac2 are the two reactions listed under reacting flow.

In my case I have changed the flow to laminar (for which it is in my case in a MEMs burner) and solve a problem with four reactions and have correctly input the dH_1 through dH_4 values (the concentration profile and fluid profile solve seamlessly without the heat transfer physics being added or the heat source 1 included), but do not know how to call the same function for 2D (rectangular geometry without any symmetry, (x,y)).

I tried:
-(dH_R1*rspf.x_yreac1+dH_R2*rspf.x_yreac2...)
Ouch...

Thank you very much for the help, I appreciate your infinitely superior expertise with COMSOL,
Justin
1 Reply Last Post Feb 10, 2015, 5:06 a.m. EST
Tero Hietanen
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Posted: 9 years ago Feb 10, 2015, 5:06 a.m. EST
Hi,

Here "rspf.rEDC_treac1" stands for reaction rate for reaction one by Eddy Dissipation Model (formula 4 in pdf). This is only valid for turbulent flows, not laminar. This reaction rate can be used in 2D, 2D-axi and 3D models. For laminar flow you have to use reaction rate by Arrhennius formulas.

Check these:

www.comsol.com/model/packed-bed-reactor-238
www.comsol.com/model/chemical-reactions-and-soot-build-up-in-a-diesel-filter-1394

Best regards

Tero Hietanen
Hi, Here "rspf.rEDC_treac1" stands for reaction rate for reaction one by Eddy Dissipation Model (formula 4 in pdf). This is only valid for turbulent flows, not laminar. This reaction rate can be used in 2D, 2D-axi and 3D models. For laminar flow you have to use reaction rate by Arrhennius formulas. Check these: http://www.comsol.com/model/packed-bed-reactor-238 http://www.comsol.com/model/chemical-reactions-and-soot-build-up-in-a-diesel-filter-1394 Best regards Tero Hietanen

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