The chemical reaction in the simulation was not carried out


In fluidized bed simulation, everything seems normal, with no error occurring, only some warnings and messages.
However, it seems that the chemical reaction did not occur and the temperature did not change. Only the flow of particles was simulated.
I have checked the “ ReactionRates array size ” mentioned in The chemical reaction does not exist - MFiX / How to - NETL Flow Science Software Support. So I don’t know how to solve it now.

There is an additional question, if I want to give a value as a variable, such as the fluctuation of import flow, how can I achieve it?
For example, defining a variable A as a function of time t, such as a sine function or a normal distribution, and define the flow rate m=A (t) * constant, is this feasible in MFIX? (72.6 MB)

Hi @yfwu

  1. The case you have attached has 36 reactions defined. Which of the reactions is not happening? Can you simplify the chemistry (say, disable some reactions) to help troubleshoot this?

  2. You should be able to implement a time-dependent flow rate using usr1_des.f

Here’s a worked example with a sinusoidal input rate:

And another related posting:

Thanks for your reply @cgw !
I followed your suggestion and reduced the number of reactions from 36 to 6, conducting another simulation.

I can see from the VTK window that no reactions have occurred in the system, and there is no temperature change in the system (chemical reactions will be accompanied by changes in heat).

I found that only sand particles can be seen, and biomass particles cannot be seen. I speculate that for some reason, biomass particles did not enter the system, so no chemical reaction occurred.

only sands can be seen

biomass particles cannot be seen

An additional issue is that my calculation results may cause crashes in Paraview, and I have already provided feedback to Paraview.
ParaView v5.12 crashed when loading results - ParaView Support - ParaView
Is there any other method for post-processing MFIX-DEM results?

The last screenshot suggests there are 42 biomass particles in the system.

If you want to load DEM data into Paraview, you need to load the pvd files, not the *_DES.RES file

I strongly suggest using Monitors to track maximum reaction rate, rather than relying on visual inspection