Species won’t solve while doing Carbon Black Simulation

    • Rama

      Hi All,

      I'm trying to do a carbon black simulation, I have the inputs from another student working on this project who has simulated the first half of the combustion chamber using non-premixed combustion model. I have taken the output species from his simulation and am trying to model my half of the chamber as species transport. However when I initiate, there is an error message saying that the species were not solved at Zone XX. and the application closes itself.

      Please help me select the right model and settings.

      P.S: I cannot model it as partially premixed combustion since the sum of the mole fraction of the gasses is more than Unity.

      Attached are references.

      First half of the furnace

      Second half of the furnace which I am modelling, the gases enter from left

    • Karthik R


      Could you please help us understand your problem better? Where is zone XX in your problem?

      what boundary conditions are you using? What are you material properties? What type of flow are you solving? Which models are you using to solve your problem? What does your mesh look like? Please help us understand the problem better so we can help you.





    • seeta gunti
      Ansys Employee

      Hello Rama,

      If I understand correctly, you are trying to solve the carbon black reactor in Fluent. You split the domain in two parts. One with reactions and another one with species transportation with no reactions. So your colleague ran the reaction part in half of the domain. Now you want to use the previous results and want to give inputs to the present domain. If my understanding is right,  You can write the interested species profiles and use those profiles as boundary conditions to your present case.





    • Rama

      Hi karthik,

      Well I was doing the carbon black formation simulation in Fluent. I have attached the images of the model below.

      this is my friends's model - the non-premixed gasses are entered trough the pipe in the left and adjacent opening is for air inlet. the combustion products are exited through the right.

      My Friend's Model

      I consider his results as my input parameters.

      other half of the reactor - My Model

      there is an additional stream of feed stock coming in trough the six pipes into the chamber

      gas Phase and feed stock

      Now I am getting an error saying that the species is not solved at some nodes. upon investigation there is a warning message while initialization "diffrent fluids encountered at different zones - zone 9 has mixture template and zone 10 has urea liquid "

      I'm new to Fluent and am unable to figure out where have i done a mistake. Please let me know If you need further details. I can share the file.




    • Rama

      Hi Seeta,

      You got it right. Can you guide me to a relevant tutorial. because the output species mole fractions from my friends simulation is summed to more than unity, hence I'm entering the mole fractions as "new-parameter". Let me know If you need any further details.




    • klu
      Ansys Employee

      Hi Rama,

      Based on the error message, would you please check if all the zones have the same material? Please go to Cell Zone Conditions, double click each cell zone (especially zone 9) and found out the Material name. Make sure all the zones use the same mixture. Thanks.

    • seeta gunti
      Ansys Employee

      As klu mentioned, there could be an issue with the assigning the right material for all the zones. All the zones should be a mixture material. 


      In the above picture, material name is a mixture material name. Similarly you should have the same materials for your cell zones.

    • Rama

      Hi Guys,

      Sorry for the delayed response, well the problem is that both the materials mix and react to form the carbon black. so i need to use

      1. mixture template

      2. the feedstock (for now i'm using urea liquid)

      and there's this error aswell

      "Error at host: Species are not solved in neighbor cell threads (6 and 7)

      of interior zone 26"


      so how do I make sure the species is solved. please let me know if i'm missing something.

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