Simplified Reaction Mechanism for CFD Simulation of Rocket Re-Entry

The chemical environment and flow characteristics during rocket re-entry are highly complex. To improve the computational efficiency of CFD simulations, a simplified reaction mechanism for the rocket re-entry CFD has been developed. Based on the Principal Component Analysis (PCA), the detailed reaction mechanism was simplified, resulting in a mechanism comprising 25 species and 34 reactions. Then the NSGA-III optimization framework was used to optimize the s25r34 mechanism. Comparison of simplified and detailed mechanisms shows that the ignition delay error of the simplified mechanism does not exceed 25%. And the temporal variation trends of three key species remain consistent with the detailed mechanism in both numerical values and trends. The errors introduced during the simplification and optimization processes are within an acceptable range. This simplified reaction mechanism can significantly improve computational efficiency while maintaining reasonable accuracy, serving a reference for CFD simulations of the rocket re-entry process.