The Multi-Zone HCCI Engine Model Extraction Utility makes use of the content of a multidimensional CFD solution for a cold-flow (nonreacting) simulation to generate a new Multi-Zone HCCI Engine model project in Ansys Chemkin and automatically populate the zonal parameters to initialize the Chemkin simulation. In this way you can accurately capture temperature stratification due to mixing effects in the precombustion portion of the engine cycle using CFD, but use very detailed kinetics in the combustion simulation using the Chemkin Multi-Zone HCCI Engine model. This approach is appropriate for Homogeneous Charge Compression Ignition (HCCI) or Premixed Charge Compression Ignition (PCCI) engine operating modes. The assumptions require that the fuel be fully vaporized and not yet reacted in the CFD model prior to the starting point where the Chemkin Multi-Zone HCCI Engine model would be extracted.