# Construction of a Chemical Kinetic Mechanism of Five-Component Surrogate Fuel for RP-3 Kerosene
## 4 Result and Discussion
### Verification of Single-Component Combustion Parameters  
#### 4.2.1 n-Dodecane  
Figure 13 presents the comparison between the predicted values of the mechanism and the ignition experimental data of n-dodecane. The experimental data stem from the research of [PERSON] [40] and [PERSON] [50]. The experimental conditions of [PERSON] were P = 1.5 MPa, \(\varphi\) = 0.5, and T from 633 to 1266 K. In the experiment, [PERSON] also took into account the condition where oxygen was diluted (N\({}_{2}\)/(N\({}_{2}\) + O\({}_{2}\)) = 0.895), as depicted in Figure 13d. [PERSON]'s experimental conditions were P = 2.2 MPa, \(\varphi\) = 0.5 and 1.0, and T within the range of 720 to 1200 K. The results suggest that under several distinct conditions, the matching of the predicted results of the mechanism with the experimental data is favorable, successfully reproducing the NTC trend of the n-dodecane component and the ignition behavior at both high and low temperatures. The performance is also satisfactory under the condition where oxygen is diluted.  
Figure 11: Verification of ignition delay times of RP-3 under oxygen dilution [22].  
Figure 12: Verification of the modification mechanism and laminar flame speed of RP-3 [14].  
Figure 14 presents the validation outcomes of the surrogate fuel reaction mechanism regarding the laminar flame speed of n-dodecane. The experimental data were derived from the measurements of [PERSON] [23], [PERSON] [41], and [PERSON] [51]. The results suggest that at a temperature of 470 K, the predicted value of the mechanism is slightly lower; under the remaining several conditions, the coupled mechanism can effectively predict the premixed laminar flame speed of n-dodecane, and the prediction results are overall in good alignment with the experimental data. It can effectively predict the variations in the laminar flame speed of n-dodecane under diverse operating conditions.  
Figure 15 presents the comparison between the predictions of the oxidation product concentrations of n-dodecane with the mechanism and the experiments of [PERSON] [50]. The experimental conditions were P = 0.1 MPa and T of 600 to 1100 K, and the diluent gas was argon. As can be observed from the figure, when the temperature is within the range of 600 to 700 K, the consumption curve of O\({}_{2}\) suddenly decreases and then rapidly increases, forming a consumption peak. This could be attributed to the relatively high rate of oxygen addition reactions of n-dodecane, resulting in an increased consumption of oxygen and the emergence of the consumption peak. Nevertheless, as the oxidation reaction progresses further, the occurrence of reactions that generate oxygen in small-molecule reactions or the reverse reactions of oxygen-consuming reactions, such as the oxidation reaction of CH\({}_{3}\) radicals with HO\({}_{2}\) radicals (CH\({}_{3}\) + HO\({}_{2}\) <=> CH\({}_{4}\) + O\({}_{2}\)) and the reaction of HO\({}_{2}\) radicals with O radicals (HO\({}_{2}\) + O <=> O\({}_{2}\) + H), may all lead to the recovery of oxygen concentration.  
Figure 13: Verification of ignition delay times for n-dodecane [40,50].  
On the whole, the surrogate fuel mixture mechanism can essentially reflect the variation pattern of the concentrations of n-dodecane oxidation products with temperature.