The objective of post-processing is the analysis and/or extraction of data obtained from the Ansys Chemkin simulations. The analysis may be as simple as comparing a set of scalar values or may require 2-D and 3-D plotting and contour capabilities. In some cases, we want to make derived calculations based on the raw Chemkin outputs.
There are three types of outputs produced by the Ansys Chemkin reactor simulations:
This file, which by default is named XMLdata_<project_name>.zip, is a compressed, XML-formatted text file comprised of multiple blocks of information. The information includes the independent and dependent variables in the system as well as any sensitivity data that was requested in the problem setup.
By using an XML format, we provide a generalized format that all of our reactor models can read and write. Each Solution File is comprised of a header block and multiple data blocks. Each block (XMLdata1.zip, etc.) is compassed, separately, but the blocks must be read consecutively and seamlessly to process the entire file as an XML-formatted stream. The Ansys Chemkin installation includes such a SAX-based XML parser program which is used by our simulation, export, and post-processing programs when working with the Solution File. The purpose of breaking the file into multiple zipped blocks is to allow large data sets to be compressed into smaller files without overwhelming the machine resources for memory during the file operations.
There are a number of derived values calculated as part of the post-processing. These values are not found within the Solution File itself and are created on the fly, using the solution data and the Ansys Chemkin utilities. Table 1.1: Output Variables Created by Derived Calculations in the Visualizer lists the derived variables that are routinely or optionally calculated for the applicable reactor models.
Diagnostic Output File (.out).
A text file listing the simulation inputs, the progress of the solution and some or all of the outputs. This is useful for a quick inspection/review and also contains any error messages generated by the application. The diagnostic output file should not be used for any post-processing or batch processing, as the format of the output is not a fixed format and may vary from one solution to another.
Pre-parsed, comma-separated input files for the Visualizer (.ckcsv).
These files are created by the post-processing step of the Parameter Study facility. They contain the aggregation of results from multiple parameterized runs of the simulation. These files are in a special format that is easily loaded by the Visualizer. They contain the derived values, as requested, that are detailed in Table 1.1: Output Variables Created by Derived Calculations in the Visualizer .
Note: Note that including sensitivity data or rate-of-production data during post-processing may result in problems involving too much memory requirements during the solution processing. For large mechanisms, consider reducing the amount of sensitivity data using the "SEN" option as described in the Chemkin Input Manual and selecting only a subset of sensitivity or ROP data during data selection for solution post-processing.
Note: If your objective is to extract the Ansys Chemkin results as an intermediate step to pass to an external program or scripting step, we provide data extraction utilities that can extract all or a subset of Solution File data into either a parsed file (.ckcsv) or further into multiple comma-separated values files that are easily loaded into Excel or other 3rd-party utilities. Please refer to the information on command-line and batch-programming options for extracting solution file information.
Table 1.1: Output Variables Created by Derived Calculations in the Visualizer
