Shock tube study of the ignition of lean n-heptane/air mixtures at intermediate temperatures and high pressures

Detailed chemical kinetic models for the low-temperature combustion of hydrocarbons with application to gasoline and diesel fuel surrogates

“…In a shock tube, ignition delay time is usually measured behind a reflected shock wave, while the corresponding temperature is calculated from the incident shock wave velocity with an estimated error of around 20 K. Four high pressure shock tubes have been used to work with air-hydrocarbon mixtures for pressures behind a reflected shock wave of up to 60 bar and then to observe autoignition at temperatures from 660 K. The first results were obtained by the team of Adomeit [118][119]127] in Aachen for n-heptane, iso-octane and n-decane. The more recent studies of Davidson et al [121,126] in Standford, Herzler et al [120] in Duisburg and Zhukov et al [128] in Moscow were mostly in good agreement with these older results [118,127] and supported the observation of a pronounced low temperature NTC region. The study of Herzler et al [120] has extended the range of studied equivalence ratios towards small values (up to 0.1), which are of interest for the development of HCCI engines.…”

An updated experimental and kinetic modeling study of n-heptane oxidation

“…Campbell et al [86] used a shock tube to measure ignition delay times for n-heptane oxidation 26 in the temperature range 651-823 K and at pressures between 6.1 and 7.4 atm at φ = 0.75 in 15% 27 O 2 /5%CO 2 /Ar and in 15% O 2 /Ar mixtures. Both first-stage (cool flame) and second-stage (total) 28 ignition delay times were measured, providing critically needed targets for further validation of kinetic 29 models.…”

“…Both first-stage (cool flame) and second-stage (total) 28 ignition delay times were measured, providing critically needed targets for further validation of kinetic 29 models. Figure 5 shows the experimental and modeling results for that study [86] which used the LLNL 30 mechanism [42], and the predictions using the current model as well as several other models [16,30,31 46]. It can be seen that the current mechanism generally shows a better performance in predicting both 32 the first and the second stage ignition delay times.…”

“…(P1-S10-S11-S11-S10-P1) C 7 H 15 Ȯ 2 -3 <=> C 7 H 14 -3 + HȮ 2 Second addition to O 2 Figure 5. Experimental (symbols) [86] and modeling results (lines) for n-heptane/15%O 2 /5%CO 2 /Ar 1 mixture ignition delay times at multiple conditions. Solid lines are predictions using current mechanism 2 and dashed lines are predictions using mechanisms from (a) Figure 12.…”

Experimental and modeling investigation of the low-temperature oxidation of n-heptane

“…The oxidation of n-heptane was previously studied in engines [1][2][3][4][5] and in several types of laboratory reactors such as shock tubes [6][7][8][9][10][11], rapid compression machines [12,13], jetstirred reactors [14][15][16], flow reactors [17], and flames [18][19][20][21][22]. Most of these studies were carried out under conditions of high temperature oxidation (temperature typically above 800 K) and relatively little attention was paid to the low-temperature oxidation of n-heptane, especially regarding the characterization of oxygenated reaction products [12,13,[15][16][17].…”