# Construction of a Chemical Kinetic Mechanism of Five-Component Surrogate Fuel for RP-3 Kerosene
## 4 Result and Discussion
### Verification of RP-3 Combustion Parameters  
Figure 10 presents the comparison between the predicted ignition delay times of the surrogate fuel mechanism and the experimental data obtained by [PERSON] [22] in shock tubes and rapid compressors. The experimental conditions were P from 1.0 to 1.5 MPa, T from 600 to 1100 K, and \(\varphi\) = 0.5, 1.0, and 1.5. Another set of data was derived from the experimental findings of [PERSON] [49] in a shock tube, with P = 1.0 MPa, T from 651 to 1220 K, and \(\varphi\) = 1.0. The outcomes reveal that at \(\varphi\) = 0.5, the coupled mechanism fails to precisely simulate the variations in the NTC region. However, at equivalence ratios of 1.0 and 1.5, the NTC phenomenon of the simulation values is more pronounced. In the high-temperature region where the temperature exceeds 1000 K, the mechanism can effectively predict the approximate linear relationship between the logarithm of the fuel ignition delay time and the reciprocal of the temperature. Based on the pre-exponential analysis, the ignition delay time of the fuel in the low and medium-temperature regions is influenced by the low-temperature oxidation reactions of large molecules. The subsequent analysis results indicate that the mechanism demonstrates a certain degree of reliability for the ignition delay time of single-component fuels. Hence, it is hypothesized that the reactions associated with the PAH sub-mechanism result in the formation of large-molecule polycyclic aromatic hydrocarbon products with lower reactivity from the small-molecule products of the fuel, causing a longer ignition delay time.  
Figure 9: Comparison of predictive performance before and after mechanism optimization [14,22].  
Figure 11 depicts the comparison between the predicted outcomes of the mechanism under oxygen-dilution conditions and the experimental data. The experimental data originated from Mao [22], where the selected experimental conditions for the dilution scenarios were N\({}_{2}\)/(N\({}_{2}\) + O\({}_{2}\)) = 0.895 and N\({}_{2}\)/(N\({}_{2}\) + O\({}_{2}\)) = 0.93, with P = 1.0 MPa and 2.0 MPa, and \(\varphi\) = 1.0 and 1.5, respectively. It can be observed from the figure that under oxygen dilution conditions, there are certain shortcomings in the mechanism's prediction of the experimental data. The predicted values in the high-temperature region are relatively low, and the prediction of the fuel's NTC behavior is inadequate. This is attributed to the fact that the mechanism has not conducted the calculation and optimization of the corresponding kinetic parameters for the oxygen dilution conditions, leading to a narrow application scope and weak predictive capability. Nevertheless, on the whole, the mechanism can reflect the variation pattern of the fuel's ignition delay time with temperature.  
Figure 12 presents the verification outcomes of the mechanism with respect to the laminar flame speed experimental data of RP-3. The experimental results are the measurement data of [PERSON] [14] in a rapid compression machine, with P from 0.1 MPa to 0.3 MPa, T from 420 to 480 K, and \(\varphi\) from 0.7 to 1.4. The results demonstrate that the coupled mechanism can precisely predict the variation pattern of the laminar flame speed with \(\varphi\). Furthermore, as the temperature varies, both at atmospheric pressure and high pressure, the simulation data are in good accordance with the experimental data, and the relative errors are all  
Figure 10: Verification of ignition delay time of RP-3 fuel [22,49].  
within \(\pm\)5%. This indicates that the surrogate fuel mechanism constructed in this research can fulfill the prediction requirements for the laminar flame speed of the actual RP-3 fuel.