@misc{NetzerSeidelRavetetal., author = {Netzer, Corinna and Seidel, Lars and Ravet, Fr{\´e}d{\´e}ric and Mauß, Fabian}, title = {Assessment of the validity of RANS knock prediction using the resonance theory}, series = {International Journal of Engine Research}, volume = {21}, journal = {International Journal of Engine Research}, number = {4}, issn = {2041-3149}, doi = {10.1177/1468087419846032}, pages = {610 -- 621}, abstract = {Following the resonance theory by Bradley and co-workers, engine knock is a consequence of an auto-ignition in the developing detonation regime. Their detonation diagram was developed using direct numerical simulations and was applied in the literature to engine knock assessment using large eddy simulations. In this work, it is analyzed if the detonation diagram can be applied for post-processing and evaluation of predicted auto-ignitions in Reynolds-averaged Navier-Stokes simulations even though the Reynolds-averaged Navier-Stokes approach cannot resolve the fine structures resolved in direct numerical simulations and large eddy simulations that lead to the prediction of a developing detonation. For this purpose, an engine operating point at the knock limit spark advance is simulated using Reynolds-averaged Navier-Stokes and large eddy simulations. The combustion is predicted using the G-equation and the well-stirred reactor model in the unburnt gases based on a detailed gasoline surrogate reaction scheme. All the predicted ignition kernels are evaluated using the resonance theory in a post-processing step. According to the different turbulence models, the predicted pressure rise rates and gradients differ. However, the predicted ignition kernel sizes and imposed gas velocities by the auto-ignition event are similar, which suggests that the auto-ignitions predicted by Reynolds-averaged Navier-Stokes simulations can be given a meaningful interpretation within the detonation diagram.}, language = {en} } @misc{NetzerPasternakSeideletal., author = {Netzer, Corinna and Pasternak, Michal and Seidel, Lars and Ravet, Fr{\´e}d{\´e}ric and Mauß, Fabian}, title = {Computationally efficient prediction of cycle-to-cycle variations in spark-ignition engines}, series = {International Journal of Engine Research}, volume = {21}, journal = {International Journal of Engine Research}, number = {4}, issn = {2041-3149}, doi = {10.1177/1468087419856493}, pages = {649 -- 663}, abstract = {Cycle-to-cycle variations are important to consider in the development of spark-ignition engines to further increase fuel conversion efficiency. Direct numerical simulation and large eddy simulation can predict the stochastics of flows and therefore cycle-to-cycle variations. However, the computational costs are too high for engineering purposes if detailed chemistry is applied. Detailed chemistry can predict the fuels' tendency to auto-ignite for different octane ratings as well as locally changing thermodynamic and chemical conditions which is a prerequisite for the analysis of knocking combustion. In this work, the joint use of unsteady Reynolds-averaged Navier-Stokes simulations for the analysis of the average engine cycle and the spark-ignition stochastic reactor model for the analysis of cycle-to-cycle variations is proposed. Thanks to the stochastic approach for the modeling of mixing and heat transfer, the spark-ignition stochastic reactor model can mimic the randomness of turbulent flows that is missing in the Reynolds-averaged Navier-Stokes modeling framework. The capability to predict cycle-to-cycle variations by the spark-ignition stochastic reactor model is extended by imposing two probability density functions. The probability density function for the scalar mixing time constant introduces a variation in the turbulent mixing time that is extracted from the unsteady Reynolds-averaged Navier-Stokes simulations and leads to variations in the overall mixing process. The probability density function for the inflammation time accounts for the delay or advancement of the early flame development. The combination of unsteady Reynolds-averaged Navier-Stokes and spark-ignition stochastic reactor model enables one to predict cycle-to-cycle variations using detailed chemistry in a fraction of computational time needed for a single large eddy simulation cycle.}, language = {en} } @misc{ShresthaVinHerbinetetal., author = {Shrestha, Krishna Prasad and Vin, Nicolas and Herbinet, Olivier and Seidel, Lars and Battin-Leclerc, Fr{\´e}d{\´e}rique and Zeuch, Thomas and Mauß, Fabian}, title = {Insights into nitromethane combustion from detailed kinetic modeling - Pyrolysis experiments in jet-stirred and flow reactors}, series = {Fuel}, volume = {261}, journal = {Fuel}, issn = {0016-2361}, doi = {https://doi.org/10.1016/j.fuel.2019.116349}, pages = {19}, abstract = {The pyrolysis of nitromethane highly diluted in helium was studied in a plug flow reactor and in a jet-stirred reactor at 1.07 bar and over the temperature range from 500 to 1100 K. Mole fraction profiles of major products and of intermediates were identified with gas chromatography and Fourier transform infrared spectroscopy. Using these experimental data, as well as published ones, we have developed a newly compiled model for the prediction of the pyrolysis and of the oxidation of nitromethane in jet-stirred and flow reactors, freely propagating, and burner-stabilized premixed flames, as well as in shock-tubes. The experimental results from the present work and from the literature are interpreted with the help of the kinetic model derived here. This study mainly focuses on the analysis of speciation in different reactors. Among the nitrogenous species, NO is found to be a major product for pyrolysis and oxidation. The model suggests that for nitromethane pyrolysis and oxidation the thermal dissociation channel to CH3 and NO2 is the main reaction path for the nitromethane degradation followed by the H-atom abstraction channel. The most sensitive reactions for nitromethane pyrolysis in a flow reactor and during pyrolysis and oxidation in a jet-stirred reactor are found to be CH3NO2(+M) ⇋ CH3 + NO2(+M) and CH3 + NO2 ⇋ CH3O + NO. The reaction CH3 + NO2 ⇋ CH3O + NO is found to be the most important reaction for all conditions studied. In a burner-stabilized premixed flame, as the mixture gets richer, the thermal dissociation channel CH3NO2(+M) ⇋ CH3 + NO2(+M) becomes more important as the contribution of the H-atom abstraction channel is decreased. Furthermore, in the burner-stabilized premixed flames, it was found that NO is mainly formed via NO2: NO2 + H ⇋ NO + OH, NO2 + CH3 ⇋ CH3O + NO. The model provided an overall reasonable agreement with the experimental data. However, for pyrolysis conditions, future work is desirable to improve predictions of intermediate species. This work extends the kinetic database and helps to improve the understanding of nitromethane chemistry. The kinetic model presented in this work can serve as a base model for hydrocarbons and oxygenated fuels higher than C2 and nitrogen-containing compounds higher than C1 as well as for pure nitrogen compounds.}, language = {en} } @misc{ShresthaEckartElbazetal., author = {Shrestha, Krishna Prasad and Eckart, Sven and Elbaz, Ayman M. and Giri, Binod Raj and Fritsche, Chris and Seidel, Lars and Roberts, William L. and Krause, Hartmut and Mauß, Fabian}, title = {A comprehensive kinetic model for dimethyl ether and dimethoxymethane oxidation and NOx interaction utilizing experimental laminar flame speed measurements at elevated pressure and temperature}, series = {Combustion and Flame}, volume = {218}, journal = {Combustion and Flame}, issn = {1556-2921}, doi = {10.1016/j.combustflame.2020.04.016}, pages = {57 -- 74}, abstract = {Laminar flame speeds of dimethyl ether and dimethoxymethane at pressures from 1 to 5 bar and initial temperatures from 298 to 373 K were determined experimentally using a constant volume spherical vessel and a heat flux burner setup. This study is the first to report dimethoxymethane laminar flame speeds at a pressure higher than 1 bar. Using these experimental data along with data available in the literature, a new kinetic model for the prediction of the oxidation behavior of dimethyl ether and dimethoxymethane in freely propagating and burner stabilized premixed flames, in shock tubes, rapid compression machines, flow reactors, and a jet-stirred reactor has been developed. The experimental results from the present work and literature are interpreted with the help of the derived kinetic model. This newly developed reaction mechanism considers the redox chemistry of NOx to accommodate the influence of the oxygen level on the onset of fuel conversion and interconversion of NO and NO2. The current model suggests that an increased O2 level promotes the HO2 production, which in turn leads to the formation of OH radicals, which promotes the combustion of the fuel/air mixture under lean conditions. The increase of OH radical concentrations is mainly via the NO/NO2 interconversion reaction channel, NO+HO2=NO2+OH, NO2+H=NO+OH, CH3OCH3+NO2=CH3OCH2+HONO, followed by the thermal decomposition of HONO. This work extends the kinetic database and helps to improve the understanding of dimethyl ether and dimethoxymethane combustion behavior. The kinetic model presented in this work can serve as a base model for hydrocarbons and oxygenated fuels higher than C2.}, language = {en} } @misc{FrankenSeidelMatriscianoetal., author = {Franken, Tim and Seidel, Lars and Matrisciano, Andrea and Mauß, Fabian and Kulzer, Andre Casal and Schuerg, Frank}, title = {Analysis of the Water Addition Efficiency on Knock Suppression for Different Octane Ratings}, series = {SAE World Congress}, journal = {SAE World Congress}, issn = {2688-3627}, doi = {10.4271/2020-01-0551}, pages = {5}, abstract = {Water injection can be applied to spark ignited gasoline engines to increase the Knock Limit Spark Advance and improve the thermal efficiency. The Knock Limit Spark Advance potential of 6 °CA to 11 °CA is shown by many research groups for EN228 gasoline fuel using experimental and simulation methods. The influence of water is multi-layered since it reduces the in-cylinder temperature by vaporization and higher heat capacity of the fresh gas, it changes the chemical equilibrium in the end gas and increases the ignition delay and decreases the laminar flame speed. The aim of this work is to extend the analysis of water addition to different octane ratings. The simulation method used for the analysis consists of a detailed reaction scheme for gasoline fuels, the Quasi-Dimensional Stochastic Reactor Model and the Detonation Diagram. The detailed reaction scheme is used to create the dual fuel laminar flame speed and combustion chemistry look-up tables. The Detonation Diagram is used as a novel approach in the Quasi-Dimensional Stochastic Reactor Model to evaluate the auto-ignition characteristic in the end gas and determine if it is a harmless deflagration or developing detonation. First, the Quasi-Dimensional Stochastic Reactor Model is trained for three engine operating points and a RON95 E10 fuel. Its performance is evaluated based on experimental results of a single cylinder research engine. Subsequently, different spark timings and water-fuel ratios are investigated for different Primary Reference Fuels. The results outline that water addition can effectively reduce the strength of auto-ignition in the end gas for different Primary Reference Fuels. Thereby, it can be stated that the reduction of the auto-ignition strength through water addition by 50 - 80 \% water-fuel ratio for high octane number fuels corresponds to the spark timing delay of 6 °CA or an increase of research octane number by 10 points.}, language = {en} } @misc{FrankenMaussSeideletal., author = {Franken, Tim and Mauß, Fabian and Seidel, Lars and Gern, Maike Sophie and Kauf, Malte and Matrisciano, Andrea and Kulzer, Andre Casal}, title = {Gasoline engine performance simulation of water injection and low-pressure exhaust gas recirculation using tabulated chemistry}, series = {International Journal of Engine Research}, volume = {21}, journal = {International Journal of Engine Research}, number = {10}, issn = {2041-3149}, doi = {10.1177/1468087420933124}, pages = {1857 -- 1877}, abstract = {This work presents the assessment of direct water injection in spark-ignition engines using single cylinder experiments and tabulated chemistry-based simulations. In addition, direct water injection is compared with cooled low-pressure exhaust gas recirculation at full load operation. The analysis of the two knock suppressing and exhaust gas cooling methods is performed using the quasi-dimensional stochastic reactor model with a novel dual fuel tabulated chemistry model. To evaluate the characteristics of the autoignition in the end gas, the detonation diagram developed by Bradley and coworkers is applied. The single cylinder experiments with direct water injection outline the decreasing carbon monoxide emissions with increasing water content, while the nitrogen oxide emissions indicate only a minor decrease. The simulation results show that the engine can be operated at l = 1 at full load using water-fuel ratios of up to 60\% or cooled low-pressure exhaust gas recirculation rates of up to 30\%. Both technologies enable the reduction of the knock probability and the decrease in the catalyst inlet temperature to protect the aftertreatment system components. The strongest exhaust temperature reduction is found with cooled low-pressure exhaust gas recirculation. With stoichiometric air-fuel ratio and water injection, the indicated efficiency is improved to 40\% and the carbon monoxide emissions are reduced. The nitrogen oxide concentrations are increased compared to the fuel-rich base operating conditions and the nitrogen oxide emissions decrease with higher water content. With stoichiometric air-fuel ratio and exhaust gas recirculation, the indicated efficiency is improved to 43\% and the carbon monoxide emissions are decreased. Increasing the exhaust gas recirculation rate to 30\% drops the nitrogen oxide emissions below the concentrations of the fuel-rich base operating conditions.}, language = {en} } @misc{ShresthaLhuillierBarbosaetal., author = {Shrestha, Krishna Prasad and Lhuillier, Charles and Barbosa, Amanda Alves and Brequigny, Pierre and Contino, Francesco and Mouna{\"i}m-Rousselle, Christine and Seidel, Lars and Mauß, Fabian}, title = {An experimental and modeling study of ammonia with enriched oxygen content and ammonia/hydrogen laminar flame speed at elevated pressure and temperature}, series = {Proceedings of the Combustion Institute}, volume = {2020}, journal = {Proceedings of the Combustion Institute}, issn = {1540-7489}, doi = {10.1016/j.proci.2020.06.197}, pages = {1 -- 12}, abstract = {Laminar flame speeds of ammonia with oxygen-enriched air (oxygen content varying from 21 to 30 vol.\%) and ammonia-hydrogen-air mixtures (fuel hydrogen content varying from 0 to 30 vol.\%) at elevated pressure (1-10 bar) and temperature (298-473 K) were determined experimentally using a constant volume combustion chamber. Moreover, ammonia laminar flame speeds with helium as an inert were measured for the first time. Using these experimental data along with published ones, we have developed a newly compiled kinetic model for the prediction of the oxidation of ammonia and ammonia-hydrogen blends in freely propagating and burner stabilized premixed flames, as well as in shock tubes, rapid compression machines and a jet-stirred reactor. The reaction mechanism also considers the formation of nitrogen oxides, as well as the reduction of nitrogen oxides depending on the conditions of the surrounding gas phase. The experimental results from the present work and the literature are interpreted with the help of the kinetic model derived here. The experiments show that increasing the initial temperature, fuel hydrogen content, or oxidizer oxygen content causes the laminar flame speed to increase, while it decreases when increasing the initial pressure. The proposed kinetic model predicts the same trends than experiments and a good agreement is found with measurements for a wide range of conditions. The model suggests that under rich conditions the N2H2 formation path is favored compared to stoichiometric condition. The most important reactions under rich conditions are: NH2+NH=N2H2+H, NH2+NH2=N2H2+H2, N2H2+H=NNH+H2 and N2H2+M=NNH+H+M. These reactions were also found to be among the most sensitive reactions for predicting the laminar flame speed for all the cases investigated.}, language = {en} } @misc{IssayevGiriElbazetal., author = {Issayev, Gani and Giri, Binod Raj and Elbaz, Ayman M. and Shrestha, Krishna Prasad and Mauß, Fabian and Roberts, William L. and Farooq, Aamir}, title = {Combustion behavior of ammonia blended with diethyl ether}, series = {Proceedings of the Combustion Institute}, volume = {38 (2021)}, journal = {Proceedings of the Combustion Institute}, number = {1}, issn = {1540-7489}, doi = {10.1016/j.proci.2020.06.337}, pages = {499 -- 506}, abstract = {Ammonia (NH3) is recognized as a carbon-free hydrogen-carrier fuel with a high content of hydrogen atoms per unit volume. Recently, ammonia has received increasing attention as a promising alternative fuel for internal combustion engine and gas turbine applications. However, the viability of ammonia fueling future combustion devices has several barriers to overcome. To overcome the challenge of its low reactivity, it is proposed to blend it with a high-reactivity fuel. In this work, we have investigated the combustion characteristics of ammonia/diethyl ether (NH3/DEE) blends using a rapid compression machine (RCM) and a constant volume spherical reactor (CVSR). Ignition delay times (IDTs) of NH3/DEE blends were measured using the RCM over a temperature range of 620 to 942 K, pressures near 20 and 40 bar, equivalence ratios (Φ) of 1 and 0.5, and a range of mole fractions of DEE, χDEE, from 0.05 to 0.2 (DEE/NH3 = 5 - 20\%). Laminar burning velocities of NH3/DEE premixed flames were measured using the CVSR at 298 K, 1 bar, Φ of 0.9 to 1.3, and χDEE from 0.1 to 0.4. Our results indicate that DEE promotes the reactivity of fuel blends resulting in significant shortening of the ignition delay times of ammonia under RCM conditions. IDTs expectedly exhibited strong dependence on pressure and equivalence ratio for a given blend. Laminar burning velocity was found to increase with increasing fraction of DEE. The burnt gas Markstein length increased with equivalence ratio for χDEE = 0.1 as seen in NH3-air flames, while the opposite evolution of Markstein length was observed with Φ for 0.1 < χDEE ≤ 0.4, as observed in isooctane-air flames. A detailed chemical kinetics model was assembled to analyze and understand the combustion characteristics of NH3/DEE blends.}, language = {en} } @misc{ElbazGiriIssayevetal., author = {Elbaz, Ayman M. and Giri, Binod Raj and Issayev, Gani and Shrestha, Krishna Prasad and Mauß, Fabian and Farooq, Aamir and Roberts, William L.}, title = {Experimental and Kinetic Modeling Study of Laminar Flame Speed of Dimethoxymethane and Ammonia Blends}, series = {Energy \& Fuels}, volume = {34}, journal = {Energy \& Fuels}, number = {11}, issn = {1520-5029}, doi = {10.1021/acs.energyfuels.0c02269}, pages = {14727 -- 14740}, abstract = {Ammonia (NH3) is considered a promising carbon-neutral fuel, with a high hydrogen content, that can diversify the global energy system. Blending ammonia with a highly reactive fuel is one possible strategy to enhance its combustion characteristics. Here, an investigation of blends of NH3 and dimethoxymethane (DMM), a biofuel with high fuel-born oxygen content and no carbon-carbon bonds, is reported. Unstretched laminar burning velocity (SL) and Markstein length of different NH3/DMM blends were experimentally determined using spherically propagating premixed flames. The DMM mole fraction was varied from 0.2 to 0.6 while measuring SL at 298 K, 0.1 MPa, and equivalence ratios (Φ) over the range of 0.8-1.3. The addition of DMM was found to immensely enhance the combustion characteristics of ammonia. DMM 20\% (by mole fraction) in the NH3/DMM blend increased SL by more than a factor of 3 over neat ammonia; such enhancement was found to be comparable to 60\% CH4 in NH3 (Φ = 0.9-1.1) blends. Increasing Φ was found to significantly decrease the burned gas Markstein length for lean cases, whereas a negligible effect was observed for rich mixtures. A composite chemical kinetic model of DMM/NH3, aimed at interpreting the high-temperature combustion chemistry, was able to reliably predict SL for neat NH3 and DMM flames. Also, the predictive capability of the kinetic model to describe SL for DMM/NH3 blends is reasonably good. Sensitivity analysis and reaction path analysis indicated that the NH3/DMM blends could be understood as dual oxidation processes of the individual fuels that are competing for the same radical pool.}, language = {en} } @misc{VanTreekRothSeideletal., author = {Van Treek, Lisa and Roth, Norbert and Seidel, Lars and Mauß, Fabian}, title = {Measurements of the laminar burning velocities of rich ethylene/air mixtures}, series = {Fuel}, volume = {275}, journal = {Fuel}, issn = {0016-2361}, doi = {10.1016/j.fuel.2020.117938}, pages = {9}, abstract = {Laminar burning velocities of premixed ethylene/air flames were investigated under fuel lean and rich conditions. The laminar burning velocities were measured with the heat flux method at atmospheric pressure and unburnt gas temperatures of 298 K. The measurements have been performed for the equivalence ratio range of Φ = 0.7-2.5 using stabilized and flat flames on a perforated burner plate under adiabatic conditions. This is the first time that experimental measurements with the heat flux method of the ethylene/air flames under super fuel rich conditions are performed. The experimental data were compared against predictions using three different kinetic models and published flame speed. The measured flame speeds agree with other published data within the error margin. The experimental and predicted laminar flames do agree at fuel lean conditions, but there are some notable discrepancies under fuel rich conditions.}, language = {en} } @misc{NetzerLiSeideletal., author = {Netzer, Corinna and Li, Tian and Seidel, Lars and Mauß, Fabian and L{\o}v{\aa}s, Terese}, title = {Stochastic Reactor-Based Fuel Bed Model for Grate Furnaces}, series = {Energy \& Fuels}, volume = {34}, journal = {Energy \& Fuels}, number = {12}, issn = {1520-5029}, doi = {10.1021/acs.energyfuels.0c02868}, pages = {16599 -- 16612}, abstract = {Biomass devolatilization and incineration in grate-fired plants are characterized by heterogeneous fuel mixtures, often incompletely mixed, dynamical processes in the fuel bed and on the particle scale, as well as heterogeneous and homogeneous chemistry. This makes modeling using detailed kinetics favorable but computationally expensive. Therefore, a computationally efficient model based on zero-dimensional stochastic reactors and reduced chemistry schemes, consisting of 83 gas-phase species and 18 species for surface reactions, is developed. Each reactor is enabled to account for the three phases: the solid phase, pore gas surrounding the solid, and the bulk gas. The stochastic reactors are connected to build a reactor network that represents the fuel bed in grate-fired furnaces. The use of stochastic reactors allows us to account for incompletely mixed fuel feeds, distributions of local temperature and local equivalence ratio within each reactor and the fuel bed. This allows us to predict the released gases and emission precursors more accurately than if a homogeneous reactor network approach was employed. The model approach is demonstrated by predicting pyrolysis conditions and two fuel beds of grate-fired plants from the literature. The developed approach can predict global operating parameters, such as the fuel bed length, species release to the freeboard, and species distributions within the fuel bed to a high degree of accuracy when compared to experiments.}, language = {en} } @misc{MatriscianoFrankenGonzalezMestreetal., author = {Matrisciano, Andrea and Franken, Tim and Gonzalez Mestre, Laura Catalina and Borg, Anders and Mauß, Fabian}, title = {Development of a Computationally Efficient Tabulated Chemistry Solver for Internal Combustion Engine Optimization Using Stochastic Reactor Models}, series = {Applied Sciences}, volume = {10}, journal = {Applied Sciences}, number = {24}, issn = {2076-3417}, doi = {10.3390/app10248979}, abstract = {The use of chemical kinetic mechanisms in computer aided engineering tools for internal combustion engine simulations is of high importance for studying and predicting pollutant formation of conventional and alternative fuels. However, usage of complex reaction schemes is accompanied by high computational cost in 0-D, 1-D and 3-D computational fluid dynamics frameworks. The present work aims to address this challenge and allow broader deployment of detailed chemistry-based simulations, such as in multi-objective engine optimization campaigns. A fast-running tabulated chemistry solver coupled to a 0-D probability density function-based approach for the modelling of compression and spark ignition engine combustion is proposed. A stochastic reactor engine model has been extended with a progress variable-based framework, allowing the use of pre-calculated auto-ignition tables instead of solving the chemical reactions on-the-fly. As a first validation step, the tabulated chemistry-based solver is assessed against the online chemistry solver under constant pressure reactor conditions. Secondly, performance and accuracy targets of the progress variable-based solver are verified using stochastic reactor models under compression and spark ignition engine conditions. Detailed multicomponent mechanisms comprising up to 475 species are employed in both the tabulated and online chemistry simulation campaigns. The proposed progress variable-based solver proved to be in good agreement with the detailed online chemistry one in terms of combustion performance as well as engine-out emission predictions (CO, CO2, NO and unburned hydrocarbons). Concerning computational performances, the newly proposed solver delivers remarkable speed-ups (up to four orders of magnitude) when compared to the online chemistry simulations. In turn, the new solver allows the stochastic reactor model to be computationally competitive with much lower order modeling approaches (i.e., Vibe-based models). It also makes the stochastic reactor model a feasible computer aided engineering framework of choice for multi-objective engine optimization campaigns.}, language = {en} } @misc{FrankenSeidelGonzalezMestreetal., author = {Franken, Tim and Seidel, Lars and Gonzalez Mestre, Laura Catalina and Shrestha, Krishna Prasad and Matrisciano, Andrea and Mauss, Fabian}, title = {Assessment of Auto-Ignition Tendency of Gasoline, Methanol, Toluene and Hydrogen Fuel Blends in Spark Ignition Engines}, series = {THIESEL 2020 Conference on Thermo-and Fluid Dynamic Processes in Direct Injection Engines}, journal = {THIESEL 2020 Conference on Thermo-and Fluid Dynamic Processes in Direct Injection Engines}, pages = {23}, abstract = {State of the art spark ignited gasoline engines achieve thermal efficiencies above 46 \% e.g. due to friction optimized crank trains, high in-cylinder tumble flow and direct fuel injection. Further improvements of thermal efficiency are expected from lean combustion, higher compression ratio and new knock-resistant fuel blends. One of the limitations to these improvements are set by the autoignition in the end gas, which can develop to knocking combustion and severely damage the internal combustion engine. The auto-ignition is enhanced by high cylinder gas temperatures and reactive species in the end gas composition. Quasi-dimensional Stochastic Reactor Model simulations with detailed chemistry allow to consider the thermochemistry properties of surrogates and complex end gas compositions. Based on the detailed reaction scheme and surrogate model, an innovative tabulated chemistry approach is utilized to generate dual-fuel laminar flame speed and combustion chemistry look-up tables. This reduces the simulation duration to seconds per cycle, while the loss in accuracy compared to solving the chemistry "online" is marginal. The auto-ignition events predicted by the tabulated chemistry simulation are evaluated using the Detonation Diagram developed by Bradley and co-workers. This advanced methodology for quasi-dimensional models evaluates the resonance between the shock wave and reactionfront velocity from auto-ignition in the end gas and determines if it is a harmful developing detonation or normal deflagration. The aim of this work is to evaluate the auto-ignition characteristics of different fuel blends. The Stochastic Reactor Model with tabulated chemistry is applied to perform a numerical analysis of the autoignition of the fuel blends and operating conditions. Experimental measurements of a single cylinder research engine operated with RON95 E10 fuel are used to train and validate the simulation model. The RON95 E10 fuel is blended with Methanol, Hydrogen and Toluene. The knock tendency based on the evaluation of auto-ignition events of the different fuel blends are analysed for three operating points at 1500 rpm 15 bar IMEP, 2000 rpm 20 bar IMEP and 2500 rpm 15 bar IMEP with advanced spark timings.}, language = {en} }