## 5 LBV of Key Hydrocarbon Components in Aviation Fuel
### LBV of N-Alkanes in Aviation Fuel  
N-alkanes are a primary component of both traditional aviation fuel and sustainable aviation fuels. These compounds exhibit an increase in LBV with rising temperatures [24; 68] and a decrease with increasing pressure [24; 69]. Among the n-alkanes, n-decane has been the most extensively studied for its LBV. [PERSON] et al. measured the LBV of n-decane under lean conditions (\(0.7\leq\Phi\leq 1\)) using the spherical flame method [70], achieving results consistent with those of [PERSON] et al., [PERSON] et al., and other researchers [71]. However, the spherical flame method used by [PERSON] et al. encounters issues with flame front irregularities under varying temperatures and pressures, complicating data acquisition under rich conditions. This issue has been addressed by other measurement methods. [PERSON] et al. utilized the counterflow flame method to investigate n-decane combustion at different temperatures [68], achieving results consistent with the predictions of [PERSON] et al. [72] and the PoliMi mechanisms [73]. The ability to measure LBV over a wide temperature range (338-650 K) in [PERSON] et al. 's study is attributed to the novel counterflow flame method. Their experimental data confirmed [PERSON] et al. 's prediction that the temperature exponent decreases as the equivalence ratio increases, reaching a minimum near 1.1. For higher carbon n-alkanes, [PERSON] et al. investigated the LBV variation of n-decane and n-dodecane at different temperatures using the stagnation flame method [72]. Their study found [PERSON] et al. 's simulation predictions accurate under lean conditions but underestimated LBV in fuel-rich mixtures [71]. [PERSON] et al. employing the spherical flame method [24], also investigated n-dodecane's LBV, and compared the results with PoliMi mechanisms and other models [73]. They attributed the discrepancies in rich conditions near an equivalence ratio of 1.4 to hydrodynamic instability effects. [PERSON] et al. conducted extensive research on the LBV of n-alkanes ranging from C5 to C12, noting that non-linear extrapolation for correcting flame stretch effects provides closer results to those of simulations, deriving values 1-4 cm/s smaller than those of linear extrapolation [74]. Data on LBV for higher-carbon alkanes are relatively scarce [75]. [PERSON] et al. measured the LBV of n-tetradecane and n-hexadecane using the counterflow flame method combined with digital particle image velocimetry, indicating that the LBV of n-tetradecane and n-hexadecane are very similar [18]. [PERSON] et al. introduced a model incorporating gas-phase pyrolysis of n-tetradecane that closely matched previous experimental results [18]. At present, research on the LBV of n-decane and n-dodecane is gaining popularity. This is partly due to their frequent use as components in surrogate fuel formulations and the abundance of relevant research and data, which can be utilized to validate the testing accuracy of the constructed equipment. For instance, [PERSON] et al. verified the accuracy of their Bunsen burner system by initially measuring the LBV of n-decane when studying the LBVof Jet A-1 and its surrogate fuels [6]. Similarly, [PERSON] et al. validated the precision of their experimental setup by first measuring the LBV of n-decane and n-dodecane before investigating the emission characteristics of Jet A-1 and its surrogate fuels using the spherical flame method [76]. Information on LBV tests for different n-alkanes is shown in Table 4.  
Taking n-decane as an example, the LBV_max obtained from different years and testing methods is plotted in Figure 6. It can be observed that, firstly, the LBV results obtained after 2010 are significantly lower than those of earlier data, and the data tend to converge. The error of the results measured using the spherical flame method in 2013 was also significantly smaller than that in 2011. This is mainly attributed to scholars' deepening understanding of LBV mechanisms in recent years.