Learning Forum

[Sulaiman_Alturaifi]

Hi,

I'm trying to run a simple simulation in Chemkin Closed Homogeneous reactor using a specific mechanism (I have attached the gas-phase kinetics file, and the thermodynamic data file). I can start by setting up the chemistry set in "pre-processing" and Chemkin will run the pre-processor successfully without any problem. I'll then setup a simple conditions in the reactor physical properties (e.g. problem type=constrain volume and solve energy equation, end time=500 microsecond, T=2000K, P=1 atm, V=1 cm3) and reactant species (e.g. H2=0.005, Ar=0.995). Then I wound run the calculation but immediately after clicking "Begin", I would get the following error.

[RK]

Hello, nAs Ansys employees we will not be able to download the files. Can you please insert images instead? Thank you. n

[Sulaiman_Alturaifi]

Hello,nThe attachment are included as extra document. I have explained my problem with images above. Do you need a specific image or is my problem unclear?nThank youn

[RK]

In regards to the output file, is it just the error message that you have mentioned or any other information? If no other information above the error message you provided, it must be a license issue. n

[Sulaiman_Alturaifi]

I don't believe there is a license issue for two reasons. First, Chemkin works when I use a different gas-kinetics and thermodynamics input files (different chemical kinetics mechanism). Second, Chemkin works for this mechanism that I'm having issues with if I change the reactant speces to only Ar (i.e. Ar = 1). I only have this issue when I start adding other species which tells me it might be something with the input files but chemkin run the pre-processor without issues. I will paste the output file in the next few comment (I will need more than one comment due to the character length limitation). Can you please look into my issue?n

[Sulaiman_Alturaifi]

[Sulaiman_Alturaifi]

[Sulaiman_Alturaifi]

[RK]

 TASK INTERRUPTED: TROUBLE IN THE TRANSIENT SOLVER DDASPK . This error gives us more information! nThe tolerances might be too tight for the species mass fractions in the reactions. You can try increasing the tolerancesn

[Sulaiman_Alturaifi]

I have tried to ply around with the solver settings (changing absolute and relative tolerances, max time step, and using all the advanced options) but without any success. I keep getting the error of task interrupted with the error message saying:nTHE MATRIX OF PARTIAL DERIVATIVES MAYBE SINGULARnCould you suggest another solution? I can share my files for you to investigate if that is possible.n

[ANAND SINGH]

Try to run the simulations by decreasing the absolute tolerance value 

[SAHAR BELMADANI]

hi, i got the same probleme .The error says: exit_status=1 .
what does that means exactlz please.