Fluids

Fluids

How to implement thermodynamic database for chemkin with ionic species and electron

    • CFDGer
      Subscriber
      Hello, nI am trying to implement an 11 species (O2, O, NO, N, N2, NO+, N2+, O2+, O+, N+, E) reaction model into Ansys Fluent but I receive the following error message:nThermo data of species e was not found, or species cp type not handledError at host: Memory allocation failed during Chemkin mechanism importnThe source for my therm.dat file is Burcat's Thermodynamic Database (7 coefficient polynomials for cp(T)): http:/garfield.chem.elte.hu/Burcat/THERM.DATnObviously this doesn't contain information regarding the electron. So my question is how to set up a simulation with an electron and ionic species in Ansys Fluent?.Thanks for your help!n
    • RK
      Ansys Employee
      Hello, nMay I please know which version you are using? Thanks.
    • CFDGer
      Subscriber
      Hello,ni am using Ansys Fluent 2020R1nnThanksn
    • Judy Cooper
      Ansys Employee
      Hi:nI think that the error here is unrelated to the species type.  nThe error Thermo data of species e was not found, or species cp type not handledError at host: Memory allocation failed during Chemkin mechanism import  nmeans that the species e  was not matched up in going from the SPECIES section of the Chemkin reaction mechanism to the thermo file - see excerpts below:nHere is a sample Chemkin Mechanism file.  Note that the species block is all Caps.nELEMENTSnO H C N ARnENDnSPECIESnH2     H      O      O2     OH     H2O    HO2    H2O2   AR     C3H7   C3H8   CH2CHO CH3CHOnENDn!THERMOn! Insert GRI-Mech thermodynamics here or use in default filen!ENDnn2.Here is a sample Thermodynamic data file. Note that the first specie in the list is in lower casenTHERMOn  300.000 1000.000 5000.000n! GRI-Mech Version 3.0 Thermodynamics released 7/30/99n! NASA Polynomial format for CHEMKIN-IIn! see README file for disclaimerno                L 1/90O  1              G  200.000 3500.000 1000.000   1n 2.56942078E+00-8.59741137E-05 4.19484589E-08-1.00177799E-11 1.22833691E-15   2n 2.92175791E+04 4.78433864E+00 3.16826710E+00-3.27931884E-03 6.64306396E-06   3n-6.12806624E-09 2.11265971E-12 2.91222592E+04 2.05193346E+00                  4n....nIn going between these files, there will be an error, because the upper case O specie and the lower case o are seen to be different, so the thermo data for specie O is not found.nOnce the species naming is made consistent between the two files, read your mechanism data into Fluent without checking Volumetric reactions under species.  This will load just the species and their properties.  Then you can go back to the Species Model Panel and activate Volumetric and Electrochemical under Reactions.  This will then allow you to enter the species charges and other electrical properties, and also your electrochemical reactions.n
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