Reduced chemical model for low and high-temperature oxidation of fuel blends relevant to internal combustion engines

Lapointe, Simon; Zhang, K.; McNenly, Matthew J.

doi:10.1016/j.proci.2018.06.139

Cited by 32 publications

(17 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Lapoint et al 42 recently reported a semiglobal approach for oxidation of fuel blends with a global-type submechanism (three species and ten reactions) describing the fuel decomposition pathways feeding into a C 0 −C 4 core mechanism. This type of model allows a better description of the NTC behavior, but at the cost of a significantly larger number of species and reactions.…”

Section: ■ Introductionmentioning

confidence: 99%

Evaluation of a Semiglobal Approach for Modeling Methane/n-Heptane Dual-Fuel Ignition

et al. 2021

View full text Add to dashboard Cite

Because of the relatively high autoignition temperature of natural gas, its use in conventional diesel engines requires a pilot fuel, typically diesel oil, to promote ignition. To conduct computational fluid dynamics (CFD) simulations of the combustion in such engines, there is a need for dual-fuel combustion models that achieve a balance between computational efficiency and accuracy. This study investigates a semiglobal approach for modeling ignition of n-heptane/methane mixtures. In the semiglobal approach, the heptane oxidation is modeled by using a four-step global scheme from Müller, Peters, and Liñán (MPL) (1992), while the methane chemistry is described by a skeletal mechanism with 22 species, derived from a detailed reaction mechanism. The resulting semiglobal model includes 25 species and 138 reactions. Both the global heptane mechanism and the merged semiglobal dual-fuel model are validated against a wide range of ignition delay data from shock tubes as well as through comparison with predictions of the detailed heptane mechanism by Zhang et al. (2016). The MPL model cannot fully capture the ignition delay across the negative temperature coefficient (NTC) region for an n-heptane/air mixture. Despite this shortcoming, the ignition delay at high pressure (38–55 atm) is predicted typically within a factor of 2 compared to experiments. Under dual-fuel conditions with methane as the main fuel, the NTC behavior is less pronounced. Methane ignition is promoted by heat release from the n-heptane oxidation rather than by any direct chemical interaction. Predictions of ignition delays using the combined global/skeletal model are in good agreement with the n-heptane/methane measurements reported by Schuh et al. (2019; 60 atm, 785–1284 K), while at the higher temperatures and lower pressures of the experiments of Liang et al. (2019; 10 atm, 1257–1763 K), predictions are accurate within a factor of 2 for methane contents of 90% and higher. The present results indicate that it is possible with a small combined model to predict the ignition delay for methane/n-heptane mixtures with sufficient accuracy for practical use. The semiglobal model approach can thus be employed in CFD simulations, facilitating development of sustainable dual-fuel engines as well as identification of optimal fuel compositions and conditions.

show abstract

Section: ■ Introductionmentioning

confidence: 99%

Evaluation of a Semiglobal Approach for Modeling Methane/n-Heptane Dual-Fuel Ignition

et al. 2021

View full text Add to dashboard Cite

show abstract

“…In addition, three mechanisms from the literature, which are n-dodecane with 65 species and 363 reactions [11,38], n-heptane with 159 species and 770 reactions [3,39], and a diesel fuel surrogate with 163 species and 887 reactions [1], are also studied.…”

Section: Surrogate Fuel Generationmentioning

confidence: 99%

Impact of Multi-Component Surrogates on the Performances, Pollutants, and Exergy of IC Engines

Mondo

Agrebi

Hamdi

et al. 2022

Entropy

View full text Add to dashboard Cite

Even though there is a pressing interest in clean energy sources, compression ignition (CI) engines, also called diesel engines, will remain of great importance for transportation sectors as well as for power generation in stationary applications in the foreseeable future. In order to promote applications dealing with complex diesel alternative fuels by facilitating their integration in numerical simulation, this paper targets three objectives. First, generate novel diesel fuel surrogates with more than one component. Here, five surrogates are generated using an advanced chemistry solver and are compared against three mechanisms from the literature. Second, validate the suggested reaction mechanisms (RMs) with experimental data. For this purpose, an engine configuration, which features a reacting spray flow evolving in a direct-injection (DI), single-cylinder, and four-stroke motor, is used. The RNG k-Epsilon coupled to power-law combustion models is applied to describe the complex in-cylinder turbulent reacting flow, while the hybrid Eulerian-Lagrangian Kelvin Helmholtz-Rayleigh Taylor (KH-RT) spray model is employed to capture the spray breakup. Third, highlight the impact of these surrogate fuels on the combustion properties along with the exergy of the engine. The results include distribution of temperature, pressure, heat release rate (HRR), vapor penetration length, and exergy efficiency. The effect of the surrogates on pollutant formation (NOX, CO, CO2) is also highlighted. The fifth surrogate showed 47% exergy efficiency. The fourth surrogate agreed well with the maximum experimental pressure, which equaled 85 Mpa. The first, second, and third surrogates registered 400, 316, and 276 g/kg fuel, respectively, of the total CO mass fraction at the outlet. These quantities were relatively higher compared to the fourth and fifth RMs.

show abstract

“…Maroteaux and Noel [38] developed two reduced n-heptane mechanisms, including 61 and 26 reactions, respectively, and the methane sub-mechanisms were also included, which however, failed to well predict the ignition delays for methane. Lapointe et al [39] developed an 8-step core sub-mechanism for n-heptane coupled with a C0-C4 sub-mechanism, which was consisted of hundreds of species and reactions, making it difficult to be adopted in the three-dimensional modeling study.…”

Section: Introductionmentioning

confidence: 99%

Development of a simplified n-heptane/methane model for high-pressure direct-injection natural gas marine engines

Liu

et al. 2021

Front. Energy

View full text Add to dashboard Cite

High-pressure direct-injection (HPDI) of natural gas is one of the most promising solutions for the future ship engines, for which the combustion process is mainly controlled by the chemical kinetics. However, the employment of detail chemical mechanisms for the multi-dimensional combustion simulation is significantly expensive due to the large scale of the marine engine. In the present study, a reduced n-heptane/methane mechanism consisted of 35-step reactions was constructed using multiple reduction approaches. Then this mechanism was further reduced to include only 27 reactions by the HyChem (Hybrid Chemistry) method. An overall good agreement with the experimentally measured ignition delay data of both nheptane and methane for these two reduced mechanisms was achieved and reasonable predictions for the measured laminar flame speeds were obtained for the 35-step mechanism. But the 27-step mechanism cannot predict the laminar flame speed very well. In addition, these two reduced mechanisms were both able to reproduce the experimentally measured in-cylinder pressure and heat release rate profiles for a HPDI natural gas marine engine, although the engine-out CO emission was overpredicted and the NOx emission was slightly underestimated. The predicted distributions of temperature and equivalence ratio by the 35-step and 27-step mechanisms are similar with those of the 334-step mechanism. However, the predicted distributions of OH and CH2O are significantly different from those of the 334-step mechanism. In short, the developed reduced chemical kinetic mechanisms provide a high-efficient and dependable method to simulate the characteristics of combustion and emissions in HPDI natural gas marine engines.

show abstract

Reduced chemical model for low and high-temperature oxidation of fuel blends relevant to internal combustion engines

Cited by 32 publications

References 27 publications

Evaluation of a Semiglobal Approach for Modeling Methane/n-Heptane Dual-Fuel Ignition

Evaluation of a Semiglobal Approach for Modeling Methane/n-Heptane Dual-Fuel Ignition

Impact of Multi-Component Surrogates on the Performances, Pollutants, and Exergy of IC Engines

Development of a simplified n-heptane/methane model for high-pressure direct-injection natural gas marine engines

Contact Info

Product

Resources

About