The issue of chemical reaction rate related to DEM

Hello, researcher.
I am very sorry for the many problems caused by my poor learning ability and ability to master new software.
I am curious why this error occurred. According to the Biomass example, I made modifications to the chemical reaction rate (usr_rates), but always reported an error. Why is this? (94.7 MB)

Additionally, in Silane_ Pyrolysis_ Pic_ There are some doubts in the code for the chemical reaction rate in the 3D example (usr_rates_des), such as: the form of the chemical reaction formula is basically similar, but why is the process of solving the chemical reaction rate different?

Secondly, why is there a pressure of hydrogen gas here? Moreover, there is Si present in the reaction product; why is there no information about Si in this formula? Also, what does this ONE mean?

Next, on line 95, why is the partial pressure of Si2H6 not listed? Why are only the diffusion coefficients and gas constants of SiH2 listed on lines 99 and 101? Why are other compounds, such as Si2H6, SiH4, etc., not listed?

I really don’t understand this operation, and no one around me can operate this process. I really don’t have a solution now. If this problem can be solved, I would greatly appreciate it.
Best wishes!

Hi @GL1. First off, no apologies are needed, there’s always new things to learn and nobody is born an expert. We are all doing our best, you are doing your best to learn, and I’m doing my best to answer questions and fix bugs in MFiX! I will reply to your questions one at a time.

You should be able to click on the file name:line number in the dialog, although I see that it is not underlined everywhere it appears (this may be an issue on Windows). This will open the editor window with the problem line selected. Alternately, use the editor of your choice to open the file and browse to usr_rates.f:95

The problem is at:

95	      RATES(Drying)    = 4.13d6 * exp(-1.058d4/TsX) * c_Moisture

The division error is happening because TsX is 0. You have to find out where this 0 is coming from, or check for TsX being nonzero before doing the division.

T_s(IJK,1) refers to the temperature of the solids phase when using TFM. It is not defined for DEM. My suggestion is to use Tgx only.

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Hello. What I’m not sure about right now is whether the rewritten reaction rate code is suitable for this example. Also, if applicable, I have made many modifications, but Tsx is still 0. May I ask what to do?

Hello, according to your suggestion, I have made an attempt but cannot run it. The result is as follows:

Additionally, although it cannot run, why do the following warnings always appear?

You can ignore the warning message. You cannot use the variable T_s(IJK,1) in a DEM simulation. Please attach your revised simulation files if you want someone to take a look.

Hello, Jeff Dietiker. I am finally waiting for your reply. Thank you very much. I have uploaded the case now, and I have debugged the code again. The reaction has not yet occurred, and there has been no product generation. I am really helpless. Please help me. Thank you very much. (58.2 MB)

I replied on the thread at The chemical reaction does not exist

Please do not create multiple threads for the same issue. Thanks.