(608a) Chemcheck: A Cantera Debugging Tool to Detect Syntax and Chemical Errors in Chemkin Files

ChemCheck is a new, open-source, tool to help visualize, diagnose, and correct the errors often found in Chemkin and Cantera input files, in order to provide an easier and more accurate result for Cantera users. Most detailed kinetic models for combustion are distributed in a Chemkin-compatible format. Many of these, however, have syntax errors and bugs that prevent them from being interpreted by other software. More contain typos and mistakes that can alter the chemical meaning. More still contain parameters describing chemistry that is infeasible or unphysical.

ChemCheck is a web application that allows users to upload chemkin files, and generate a new Cantera input file in YAML format. Syntax errors that prevent conversion are diagnosed by ChemCheck, with diagnostic messages to help fix common mistakes, such as missing digits from the end of line, missing exponential signs 'E', and missing comment sign “!”.

After conversion, ChemCheck looks for several physical and chemical errors. ChemCheck detects species with discontinuous NASA polynomial data and plots figures to help users visualize the discontinuity. Bimolecular reactions exceeding the collision limit (usually in the reverse direction) are detected and rendered in a list. Another chemical error that can be detected is reaction rate expressions which leads to an overall negative reaction rate coefficient.

Determining the chemical reasons behind failures of the ODE solver (eg. CVODE) is always an obstacle for debugging kinetic models in Cantera, so another goal of ChemCheck is to interpret the ODE solver error messages and provide suggestions to change the chemistry, usually reducing stiffness.

ChemCheck has successfully detected either syntax or chemical errors in many models during the development process, with more test files being collected and applied to evaluate and develop the software. This material is based upon work supported by the National Science Foundation under Grant No. 1931389.