The combustion timing of auto-ignited combustion is determined by composition, temperature, and pressure of cylinder charge. Thus, for a successful auto-ignition, those key variables must be controlled within tight target ranges, which is challenging due to (i) nature of coupling between those variables, and (ii) complexity of managing multiple actuators in the engine. In this article, a control strategy that manages multiple actuators of a boosted homogeneous charge compression ignition (HCCI) engine is developed to maintain robust auto-ignited combustion. The HCCI engine being considered is equipped with multiple boosting devices including a supercharger and a turbocharger in addition to conventional actuators and sensors. Since each boosting device has its own pros and cons, harmonizing those boosting devices is crucial for successful transient operation. To address the multi-variable transient control problem, speed-gradient control methodology is applied to minimize coupling between boosting devices. Simulation results show that the control strategy overcomes turbo lag by utilizing the supercharger during transient. The controller developed is still appliable to manage multiple boosting devices with conventional engines as well as HCCI engine.
{"title":"Auto-Ignited Combustion Control in an Engine Equipped with Multiple\u0000 Boosting Devices","authors":"Jun-Mo Kang","doi":"10.4271/03-17-06-0043","DOIUrl":"https://doi.org/10.4271/03-17-06-0043","url":null,"abstract":"The combustion timing of auto-ignited combustion is determined by composition,\u0000 temperature, and pressure of cylinder charge. Thus, for a successful\u0000 auto-ignition, those key variables must be controlled within tight target\u0000 ranges, which is challenging due to (i) nature of coupling between those\u0000 variables, and (ii) complexity of managing multiple actuators in the engine. In\u0000 this article, a control strategy that manages multiple actuators of a boosted\u0000 homogeneous charge compression ignition (HCCI) engine is developed to maintain\u0000 robust auto-ignited combustion. The HCCI engine being considered is equipped\u0000 with multiple boosting devices including a supercharger and a turbocharger in\u0000 addition to conventional actuators and sensors. Since each boosting device has\u0000 its own pros and cons, harmonizing those boosting devices is crucial for\u0000 successful transient operation. To address the multi-variable transient control\u0000 problem, speed-gradient control methodology is applied to minimize coupling\u0000 between boosting devices. Simulation results show that the control strategy\u0000 overcomes turbo lag by utilizing the supercharger during transient. The\u0000 controller developed is still appliable to manage multiple boosting devices with\u0000 conventional engines as well as HCCI engine.","PeriodicalId":47948,"journal":{"name":"SAE International Journal of Engines","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2024-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141389005","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Reinforcement learning (RL) is a computational approach to understanding and automating goal-directed learning and decision-making. The difference from other computational approaches is the emphasis on learning by an agent from direct interaction with its environment to achieve long-term goals [1]. In this work, the RL algorithm was implemented using Python. This then enables the RL algorithm to make decisions to optimize the output from the system and provide real-time adaptation to changes and their retention for future usage. A diesel engine is a complex system where a RL algorithm can address the NOx–soot emissions trade-off by controlling fuel injection quantity and timing. This study used RL to optimize the fuel injection timing to get a better NO–soot trade-off for a common rail diesel engine. The diesel engine utilizes a pilot–main and a pilot–main–post-fuel injection strategy. Change of fuel injection quantity was not attempted in this study as the main objective was to demonstrate the use of RL algorithms while maintaining a constant indicated mean effective pressure. A change in fuel quantity has a larger influence on the indicated mean effective pressure than a change in fuel injection timing. The focus of this work was to present a novel methodology of using the 3D combustion data from analysis software in the form of a functional mock-up unit (FMU) and showcasing the implementation of a RL algorithm in Python language to interact with the FMU to reduce the NO and soot emissions by suggesting changes to the main injection timing in a pilot–main and pilot–main–post-injection strategy. RL algorithms identified the operating injection strategy, i.e., main injection timing for a pilot–main and pilot–main–post-injection strategy, reducing NO emissions from 38% to 56% and soot emissions from 10% to 90% for a range of fuel injection strategies.
{"title":"Optimizing Fuel Injection Timing for Multiple Injection Using\u0000 Reinforcement Learning and Functional Mock-up Unit for a Small-bore Diesel\u0000 Engine","authors":"Abhijeet Vaze, Pramod S. Mehta, Anand Krishnasamy","doi":"10.4271/03-17-06-0041","DOIUrl":"https://doi.org/10.4271/03-17-06-0041","url":null,"abstract":"Reinforcement learning (RL) is a computational approach to understanding and\u0000 automating goal-directed learning and decision-making. The difference from other\u0000 computational approaches is the emphasis on learning by an agent from direct\u0000 interaction with its environment to achieve long-term goals [1]. In this work, the RL algorithm was\u0000 implemented using Python. This then enables the RL algorithm to make decisions\u0000 to optimize the output from the system and provide real-time adaptation to\u0000 changes and their retention for future usage. A diesel engine is a complex\u0000 system where a RL algorithm can address the NOx–soot emissions\u0000 trade-off by controlling fuel injection quantity and timing. This study used RL\u0000 to optimize the fuel injection timing to get a better NO–soot trade-off for a\u0000 common rail diesel engine. The diesel engine utilizes a pilot–main and a\u0000 pilot–main–post-fuel injection strategy. Change of fuel injection quantity was\u0000 not attempted in this study as the main objective was to demonstrate the use of\u0000 RL algorithms while maintaining a constant indicated mean effective pressure. A\u0000 change in fuel quantity has a larger influence on the indicated mean effective\u0000 pressure than a change in fuel injection timing. The focus of this work was to\u0000 present a novel methodology of using the 3D combustion data from analysis\u0000 software in the form of a functional mock-up unit (FMU) and showcasing the\u0000 implementation of a RL algorithm in Python language to interact with the FMU to\u0000 reduce the NO and soot emissions by suggesting changes to the main injection\u0000 timing in a pilot–main and pilot–main–post-injection strategy. RL algorithms\u0000 identified the operating injection strategy, i.e., main injection timing for a\u0000 pilot–main and pilot–main–post-injection strategy, reducing NO emissions from\u0000 38% to 56% and soot emissions from 10% to 90% for a range of fuel injection\u0000 strategies.","PeriodicalId":47948,"journal":{"name":"SAE International Journal of Engines","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2024-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141016341","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dominik Krnac, Bhuvaneswaran Manickam, Peter Holand, Utkarsh Pathak, Valentin Scharl, T. Sattelmayer
Using ammonia as a carbon-free fuel is a promising way to reduce greenhouse gas emissions in the maritime sector. Due to the challenging fuel properties, like high autoignition temperature, high latent heat of vaporization, and low laminar flame speeds, a dual-fuel combustion process is the most promising way to use ammonia as a fuel in medium-speed engines. Currently, many experimental investigations regarding premixed and diffusive combustion are carried out. A numerical approach has been employed to simulate the complex dual-fuel combustion process to better understand the influences on the diffusive combustion of ammonia ignited by a diesel pilot. The simulation results are validated based on optical investigations conducted in a rapid compression–expansion machine (RCEM). The present work compares a tabulated chemistry simulation approach to complex chemistry-based simulations. The investigations evaluate the accuracy of both modeling approaches and point out the limitations and weaknesses of the tabulated chemistry approach. When using two fuels, the tabulated chemistry approach cannot reproduce misfiring events due to inherent model limitations. By adjusting the model parameters of the tabulated chemistry model, it is possible to reproduce experimental results accurately for a specific case. However, using the adjusted parameters for simulations with changed injection timing or interaction angle between the sprays shows that no predictive calculations are possible. The parameter set is only valid for a single operation point. Further simulations show that the complex chemistry approach can capture the complex interaction between both directly injected fuels for different operation points. It correctly predicts the ignition as well as heat release. Therefore, the approach allows predictive combustion simulations. Furthermore, it reproduces the occurrence of misfiring in cases of unsuitable interaction of both sprays and injection timing.
{"title":"Comparison of Tabulated and Complex Chemistry Approaches for\u0000 Ammonia–Diesel Dual-Fuel Combustion Simulation","authors":"Dominik Krnac, Bhuvaneswaran Manickam, Peter Holand, Utkarsh Pathak, Valentin Scharl, T. Sattelmayer","doi":"10.4271/03-17-07-0055","DOIUrl":"https://doi.org/10.4271/03-17-07-0055","url":null,"abstract":"Using ammonia as a carbon-free fuel is a promising way to reduce greenhouse gas\u0000 emissions in the maritime sector. Due to the challenging fuel properties, like\u0000 high autoignition temperature, high latent heat of vaporization, and low laminar\u0000 flame speeds, a dual-fuel combustion process is the most promising way to use\u0000 ammonia as a fuel in medium-speed engines.\u0000\u0000 \u0000Currently, many experimental investigations regarding premixed and diffusive\u0000 combustion are carried out. A numerical approach has been employed to simulate\u0000 the complex dual-fuel combustion process to better understand the influences on\u0000 the diffusive combustion of ammonia ignited by a diesel pilot. The simulation\u0000 results are validated based on optical investigations conducted in a rapid\u0000 compression–expansion machine (RCEM). The present work compares a tabulated\u0000 chemistry simulation approach to complex chemistry-based simulations. The\u0000 investigations evaluate the accuracy of both modeling approaches and point out\u0000 the limitations and weaknesses of the tabulated chemistry approach. When using\u0000 two fuels, the tabulated chemistry approach cannot reproduce misfiring events\u0000 due to inherent model limitations. By adjusting the model parameters of the\u0000 tabulated chemistry model, it is possible to reproduce experimental results\u0000 accurately for a specific case. However, using the adjusted parameters for\u0000 simulations with changed injection timing or interaction angle between the\u0000 sprays shows that no predictive calculations are possible. The parameter set is\u0000 only valid for a single operation point.\u0000\u0000 \u0000Further simulations show that the complex chemistry approach can capture the\u0000 complex interaction between both directly injected fuels for different operation\u0000 points. It correctly predicts the ignition as well as heat release. Therefore,\u0000 the approach allows predictive combustion simulations. Furthermore, it\u0000 reproduces the occurrence of misfiring in cases of unsuitable interaction of\u0000 both sprays and injection timing.","PeriodicalId":47948,"journal":{"name":"SAE International Journal of Engines","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2024-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140686992","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mohamed Mohamed, Milad Mirshahi, Changzhao Jiang, Hua Zhao, A. Harrington, J. Hall
A detailed investigation was carried out on the performance, combustion, and emissions of a single-cylinder direct injection hydrogen spark ignition (SI) engine with either a side-mounted direct injection (SDI) or a centrally installed direct injection (CDI) injector. The first part of the study analyzed the performance and emissions characteristics of CDI and SDI engine operations with different injection timings and pressures. This was followed by comparing the engine’s performance and emissions of the CDI and SDI operations at different engine speeds and relative air-to-fuel ratios (lambda) with the optimized injection pressure and timings. Furthermore, the performance and emission attributes of the hydrogen engine with the CDI and SDI setups were conducted at a fixed λ value of 2.75 across a broad spectrum of engine loads. The study’s main outcome demonstrates that both direct injection systems produced near-zero CO2, CO, and HC emissions. Stable engine operations could be achieved over a wide range of air-to-fuel ratios by the CDI and SDI setups, though the CDI enabled a wider range from stoichiometric to lambda = 3.8. The CDI system also offered noticeably higher thermal efficiencies than the SDI engine. The study also illustrated the sensitivity of each injection system to the variation of the injection pressure and timing and identified the optimum operation settings for each system. Finally, the study indicates that the emissions characteristics of CDI and SDI are similar at low and mid-load, although SDI resulted in both higher NOx and hydrogen emissions than CDI.
{"title":"Hydrogen Injection Position Impact: Experimental Analysis of Central\u0000 Direct Injection and Side Direct Injection in Engines","authors":"Mohamed Mohamed, Milad Mirshahi, Changzhao Jiang, Hua Zhao, A. Harrington, J. Hall","doi":"10.4271/03-17-05-0038","DOIUrl":"https://doi.org/10.4271/03-17-05-0038","url":null,"abstract":"A detailed investigation was carried out on the performance, combustion, and\u0000 emissions of a single-cylinder direct injection hydrogen spark ignition (SI)\u0000 engine with either a side-mounted direct injection (SDI) or a centrally\u0000 installed direct injection (CDI) injector.\u0000\u0000 \u0000The first part of the study analyzed the performance and emissions\u0000 characteristics of CDI and SDI engine operations with different injection\u0000 timings and pressures. This was followed by comparing the engine’s performance\u0000 and emissions of the CDI and SDI operations at different engine speeds and\u0000 relative air-to-fuel ratios (lambda) with the optimized injection pressure and\u0000 timings. Furthermore, the performance and emission attributes of the hydrogen\u0000 engine with the CDI and SDI setups were conducted at a fixed λ value of 2.75\u0000 across a broad spectrum of engine loads.\u0000\u0000 \u0000The study’s main outcome demonstrates that both direct injection systems produced\u0000 near-zero CO2, CO, and HC emissions. Stable engine operations could\u0000 be achieved over a wide range of air-to-fuel ratios by the CDI and SDI setups,\u0000 though the CDI enabled a wider range from stoichiometric to lambda = 3.8. The\u0000 CDI system also offered noticeably higher thermal efficiencies than the SDI\u0000 engine. The study also illustrated the sensitivity of each injection system to\u0000 the variation of the injection pressure and timing and identified the optimum\u0000 operation settings for each system. Finally, the study indicates that the\u0000 emissions characteristics of CDI and SDI are similar at low and mid-load,\u0000 although SDI resulted in both higher NOx and hydrogen emissions than CDI.","PeriodicalId":47948,"journal":{"name":"SAE International Journal of Engines","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2024-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140689009","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study demonstrates the defossilized operation of a heavy-duty port-fuel-injected dual-fuel engine and highlights its potential benefits with minimal retrofitting effort. The investigation focuses on the optical characterization of the in-cylinder processes, ranging from mixture formation, ignition, and combustion, on a fully optically accessible single-cylinder research engine. The article revisits selected operating conditions in a thermodynamic configuration combined with Fourier transform infrared spectroscopy. One approach is to quickly diminish fossil fuel use by retrofitting present engines with decarbonized or defossilized alternatives. As both fuels are oxygenated, a considerable change in the overall ignition limits, air–fuel equivalence ratio, burning rate, and resistance against undesired pre-ignition or knocking is expected, with dire need of characterization. Two simultaneous high-speed recording channels granted cycle-resolved access to the natural flame luminosity, which was recorded in red/green/blue and OH chemiluminescence. Selected conditions were investigated in more detail with the simultaneous application of planar laser-induced fluorescence of OH and HCHO and recording natural flame luminescence in a cycle-averaged manner. Poly oxymethylene dimethyl ether was used as pilot fuel, building on prior investigations. The mixture of 65 vol% Dimethyl Carbonate and 35 vol% Methyl Formate with prior verification on a passenger-car-sized engine substitutes synthetic natural gas in this study. Thermodynamically, the increased compression ratio up to 17.6 resulted in feasible operation and increased indicated efficiency. On the lower compression ratio of 15.48, a more comprehensive range of applicable air–fuel equivalence ratios and increased degrees of freedom regarding the pilot’s total energy share are observed compared to the base configuration with natural gas and EN590 as pilot fuel. The air–fuel equivalence ratio sweep from λ = 1.0–2.0 revealed predominantly premixed and high-temperature heat release via OH*. The temporal and spatial evolution shifts while leaning out the mixture with increasing gradients on the radial distribution and decouples for lean mixtures from the initial spray trajectory.
{"title":"Potential Analysis of Defossilized Operation of a Heavy-Duty\u0000 Dual-Fuel Engine Utilizing Dimethyl Carbonate/Methyl Formate as Primary and Poly\u0000 Oxymethylene Dimethyl Ether as Pilot Fuel","authors":"Markus Mühlthaler, Martin Härtl, M. Jaensch","doi":"10.4271/03-17-07-0053","DOIUrl":"https://doi.org/10.4271/03-17-07-0053","url":null,"abstract":"This study demonstrates the defossilized operation of a heavy-duty\u0000 port-fuel-injected dual-fuel engine and highlights its potential benefits with\u0000 minimal retrofitting effort. The investigation focuses on the optical\u0000 characterization of the in-cylinder processes, ranging from mixture formation,\u0000 ignition, and combustion, on a fully optically accessible single-cylinder\u0000 research engine. The article revisits selected operating conditions in a\u0000 thermodynamic configuration combined with Fourier transform infrared\u0000 spectroscopy.\u0000\u0000 \u0000One approach is to quickly diminish fossil fuel use by retrofitting present\u0000 engines with decarbonized or defossilized alternatives. As both fuels are\u0000 oxygenated, a considerable change in the overall ignition limits, air–fuel\u0000 equivalence ratio, burning rate, and resistance against undesired pre-ignition\u0000 or knocking is expected, with dire need of characterization.\u0000\u0000 \u0000Two simultaneous high-speed recording channels granted cycle-resolved access to\u0000 the natural flame luminosity, which was recorded in red/green/blue and OH\u0000 chemiluminescence.\u0000\u0000 \u0000Selected conditions were investigated in more detail with the simultaneous\u0000 application of planar laser-induced fluorescence of OH and HCHO and recording\u0000 natural flame luminescence in a cycle-averaged manner.\u0000\u0000 \u0000Poly oxymethylene dimethyl ether was used as pilot fuel, building on prior\u0000 investigations. The mixture of 65 vol% Dimethyl Carbonate and 35 vol% Methyl\u0000 Formate with prior verification on a passenger-car-sized engine substitutes\u0000 synthetic natural gas in this study.\u0000\u0000 \u0000Thermodynamically, the increased compression ratio up to 17.6 resulted in\u0000 feasible operation and increased indicated efficiency. On the lower compression\u0000 ratio of 15.48, a more comprehensive range of applicable air–fuel equivalence\u0000 ratios and increased degrees of freedom regarding the pilot’s total energy share\u0000 are observed compared to the base configuration with natural gas and EN590 as\u0000 pilot fuel.\u0000\u0000 \u0000The air–fuel equivalence ratio sweep from λ = 1.0–2.0 revealed predominantly\u0000 premixed and high-temperature heat release via OH*. The temporal and spatial\u0000 evolution shifts while leaning out the mixture with increasing gradients on the\u0000 radial distribution and decouples for lean mixtures from the initial spray\u0000 trajectory.","PeriodicalId":47948,"journal":{"name":"SAE International Journal of Engines","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2024-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140689623","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Various feedstocks can be employed for biodiesel production, leading to considerable variation in composition and engine fuel characteristics. Using biodiesels originating from diverse feedstocks introduces notable variations in engine characteristics. Therefore, it is imperative to scrutinize the composition and properties of biodiesel before deployment in engines, a task facilitated by predictive models. Additionally, the international commercialization of biodiesel fuel is contingent upon stringent regulations. The traditional experimental measurement of biodiesel properties is laborious and expensive, necessitating skilled personnel. Predictive models offer an alternative approach by estimating biodiesel properties without depending on experimental measurements. This research is centered on building models that correlate mid-infrared spectra of biodiesel and critical fuel properties, encompassing kinematic viscosity, cetane number, and calorific value. The novelty of this investigation lies in exploring the suitability of support vector machine (SVM) regression, a burgeoning machine learning algorithm, for developing these models. Hyperparameter optimization for the SVM models was conducted using the grid search method, Bayesian optimization, and gray wolf optimization algorithms. The resultant SVM models exhibited a noteworthy reduction in mean absolute percentage error (MAPE) for the prediction of biodiesel viscosity (3.1%), cetane number (3%), and calorific value (2.1%). SVM regression, thus, emerges as a proficient machine learning algorithm capable of establishing correlations between the mid-infrared spectra of biodiesel and its properties, facilitating the reliable prediction of biodiesel characteristics.
{"title":"Spectroscopy-Based Machine Learning Approach to Predict Engine Fuel\u0000 Properties of Biodiesel","authors":"Kiran Raj Bukkarapu, Anand Krishnasamy","doi":"10.4271/03-17-07-0051","DOIUrl":"https://doi.org/10.4271/03-17-07-0051","url":null,"abstract":"Various feedstocks can be employed for biodiesel production, leading to\u0000 considerable variation in composition and engine fuel characteristics. Using\u0000 biodiesels originating from diverse feedstocks introduces notable variations in\u0000 engine characteristics. Therefore, it is imperative to scrutinize the\u0000 composition and properties of biodiesel before deployment in engines, a task\u0000 facilitated by predictive models. Additionally, the international\u0000 commercialization of biodiesel fuel is contingent upon stringent regulations.\u0000 The traditional experimental measurement of biodiesel properties is laborious\u0000 and expensive, necessitating skilled personnel. Predictive models offer an\u0000 alternative approach by estimating biodiesel properties without depending on\u0000 experimental measurements. This research is centered on building models that\u0000 correlate mid-infrared spectra of biodiesel and critical fuel properties,\u0000 encompassing kinematic viscosity, cetane number, and calorific value. The\u0000 novelty of this investigation lies in exploring the suitability of support\u0000 vector machine (SVM) regression, a burgeoning machine learning algorithm, for\u0000 developing these models. Hyperparameter optimization for the SVM models was\u0000 conducted using the grid search method, Bayesian optimization, and gray wolf\u0000 optimization algorithms. The resultant SVM models exhibited a noteworthy\u0000 reduction in mean absolute percentage error (MAPE) for the prediction of\u0000 biodiesel viscosity (3.1%), cetane number (3%), and calorific value (2.1%). SVM\u0000 regression, thus, emerges as a proficient machine learning algorithm capable of\u0000 establishing correlations between the mid-infrared spectra of biodiesel and its\u0000 properties, facilitating the reliable prediction of biodiesel\u0000 characteristics.","PeriodicalId":47948,"journal":{"name":"SAE International Journal of Engines","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2024-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140714259","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Driving schedule of every vehicle involves transient operation in the form of changing engine speed and load conditions, which are relatively unchanged during steady-state conditions. As well, the results from transient conditions are more likely to reflect the reality. So, the current research article is focused on analyzing the biofuel-like lemon peel oil (LPO) behavior under real-world transient conditions with fuel injection parameter MAP developed from steady-state experiments. At first, engine parameters and response MAPs are developed by using a response surface methodology (RSM)-based multi-objective optimization technique. Then, the vehicle model has been developed by incorporating real-world transient operating conditions. Finally, the developed injection parameters and response MAPs are embedded in the vehicle model to analyze the biofuel behavior under transient operating conditions. The results obtained for diesel-fueled light commercial vehicle (LCV) have shown better fuel economy than LPO biofuel with their developed fuel injection parameter MAP. The maximum BTE obtained was 29.7% for diesel and 29.5% for LPO at 2100 rpm and 20 Nm torque. The mean HC emissions were identified as 0.02046 g/km for diesel and 0.03488 g/km for LPO fuel over the modified Indian driving cycle (MIDC). Except for NOx emission, LPO biofuel exhibited diesel-like performance and emission characteristics under the MIDC.
{"title":"Suitability Study of Biofuel Blend for Light Commercial Vehicle\u0000 Application under Real-World Transient Operating Conditions","authors":"Pajarla Saiteja, B. Ashok","doi":"10.4271/03-17-07-0050","DOIUrl":"https://doi.org/10.4271/03-17-07-0050","url":null,"abstract":"Driving schedule of every vehicle involves transient operation in the form of\u0000 changing engine speed and load conditions, which are relatively unchanged during\u0000 steady-state conditions. As well, the results from transient conditions are more\u0000 likely to reflect the reality. So, the current research article is focused on\u0000 analyzing the biofuel-like lemon peel oil (LPO) behavior under real-world\u0000 transient conditions with fuel injection parameter MAP developed from\u0000 steady-state experiments. At first, engine parameters and response MAPs are\u0000 developed by using a response surface methodology (RSM)-based multi-objective\u0000 optimization technique. Then, the vehicle model has been developed by\u0000 incorporating real-world transient operating conditions. Finally, the developed\u0000 injection parameters and response MAPs are embedded in the vehicle model to\u0000 analyze the biofuel behavior under transient operating conditions. The results\u0000 obtained for diesel-fueled light commercial vehicle (LCV) have shown better fuel\u0000 economy than LPO biofuel with their developed fuel injection parameter MAP. The\u0000 maximum BTE obtained was 29.7% for diesel and 29.5% for LPO at 2100 rpm and 20\u0000 Nm torque. The mean HC emissions were identified as 0.02046 g/km for diesel and\u0000 0.03488 g/km for LPO fuel over the modified Indian driving cycle (MIDC). Except\u0000 for NOx emission, LPO biofuel exhibited diesel-like performance and emission\u0000 characteristics under the MIDC.","PeriodicalId":47948,"journal":{"name":"SAE International Journal of Engines","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2024-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140720079","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Increasing engine efficiency is essential to reducing emissions, which is a priority for automakers. Unconventional modes such as boosted and highly dilute operation have the potential to increase engine efficiency but suffer from stability concerns and cyclic variability. To aid engineers in designing ignition systems that reduce cyclic variability in such engine operation modes, reliable and accurate spark-ignition models are necessary. In this article, a Lagrangian–Eulerian spark-ignition (LESI) model is used to simulate electrical discharge, spark channel elongation, and ignition in inert or reacting crossflow within a combustion vessel, at different pressures, flow speeds, and dilution rates. First the model formulation is briefly revisited. Then, the experimental and simulations setups are presented. The results showcase the model’s ability to predict the secondary circuit voltage, current, and power signals, in addition to the spark channel elongation, for the inert cases, or flame front growth, for the reacting cases. The results also compare simulation spark channel and flame growth plots to experimental Schlieren images at different instants in time. This work serves to highlight LESI’s ability to predict the characteristics of discharge and ignition across a variety of operating conditions.
{"title":"Application of a Comprehensive Lagrangian–Eulerian Spark-Ignition\u0000 Model to Different Operating Conditions","authors":"Samuel J. Kazmouz, R. Scarcelli, Matthew Bresler","doi":"10.4271/03-17-05-0036","DOIUrl":"https://doi.org/10.4271/03-17-05-0036","url":null,"abstract":"Increasing engine efficiency is essential to reducing emissions, which is a\u0000 priority for automakers. Unconventional modes such as boosted and highly dilute\u0000 operation have the potential to increase engine efficiency but suffer from\u0000 stability concerns and cyclic variability. To aid engineers in designing\u0000 ignition systems that reduce cyclic variability in such engine operation modes,\u0000 reliable and accurate spark-ignition models are necessary. In this article, a\u0000 Lagrangian–Eulerian spark-ignition (LESI) model is used to simulate electrical\u0000 discharge, spark channel elongation, and ignition in inert or reacting crossflow\u0000 within a combustion vessel, at different pressures, flow speeds, and dilution\u0000 rates. First the model formulation is briefly revisited. Then, the experimental\u0000 and simulations setups are presented. The results showcase the model’s ability\u0000 to predict the secondary circuit voltage, current, and power signals, in\u0000 addition to the spark channel elongation, for the inert cases, or flame front\u0000 growth, for the reacting cases. The results also compare simulation spark\u0000 channel and flame growth plots to experimental Schlieren images at different\u0000 instants in time. This work serves to highlight LESI’s ability to predict the\u0000 characteristics of discharge and ignition across a variety of operating\u0000 conditions.","PeriodicalId":47948,"journal":{"name":"SAE International Journal of Engines","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2024-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140729713","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The water droplet erosion (WDE) on high-speed rotating wheels appears in several engineering fields such as wind turbines, stationary steam turbines, fuel cell turbines, and turbochargers. The main reasons for this phenomenon are the high relative velocity difference between the colliding particles and the rotor, as well as the presence of inadequate material structure and surface parameters. One of the latest challenges in this area is the compressor wheels used in turbochargers, which has a speed up to 300,000 rpm and have typically been made of aluminum alloy for decades, to achieve the lowest possible rotor inertia. However, while in the past this component was only encountered with filtered air, nowadays, due to developments in compliance with tightening emission standards, various fluids also collide with the spinning blades, which can cause mechanical damage. One such fluid is the condensed water in the low-pressure exhaust gas recirculation channel (LP-EGR) formulated at cold starts and low-speed high load conditions. This kind of design has been developed to reduce nitrogen oxide emissions and is used in both gasoline and diesel engines. This article presents a state-of-the-art review of this WDE process, focusing on the formation of the condensed water before the compressor wheel, summarizing the influencing factors of WDE and the effects of the damage including using component testbench experiences and simulation methodologies. Inspection possibilities such as high-speed camera measurement and vibration analysis are also an important part of the document.
{"title":"Water Droplet Collison and Erosion on High-Speed Spinning\u0000 Wheels","authors":"Richárd Takács, I. Zsoldos, Dániel Szentendrei","doi":"10.4271/03-17-05-0037","DOIUrl":"https://doi.org/10.4271/03-17-05-0037","url":null,"abstract":"The water droplet erosion (WDE) on high-speed rotating wheels appears in several\u0000 engineering fields such as wind turbines, stationary steam turbines, fuel cell\u0000 turbines, and turbochargers. The main reasons for this phenomenon are the high\u0000 relative velocity difference between the colliding particles and the rotor, as\u0000 well as the presence of inadequate material structure and surface parameters.\u0000 One of the latest challenges in this area is the compressor wheels used in\u0000 turbochargers, which has a speed up to 300,000 rpm and have typically been made\u0000 of aluminum alloy for decades, to achieve the lowest possible rotor inertia.\u0000 However, while in the past this component was only encountered with filtered\u0000 air, nowadays, due to developments in compliance with tightening emission\u0000 standards, various fluids also collide with the spinning blades, which can cause\u0000 mechanical damage. One such fluid is the condensed water in the low-pressure\u0000 exhaust gas recirculation channel (LP-EGR) formulated at cold starts and\u0000 low-speed high load conditions. This kind of design has been developed to reduce\u0000 nitrogen oxide emissions and is used in both gasoline and diesel engines. This\u0000 article presents a state-of-the-art review of this WDE process, focusing on the\u0000 formation of the condensed water before the compressor wheel, summarizing the\u0000 influencing factors of WDE and the effects of the damage including using\u0000 component testbench experiences and simulation methodologies. Inspection\u0000 possibilities such as high-speed camera measurement and vibration analysis are\u0000 also an important part of the document.","PeriodicalId":47948,"journal":{"name":"SAE International Journal of Engines","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2024-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140744429","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xin Yu, Anqi Zhang, Andrew Baur, Nayan Engineer, David Cleary
Improving thermal efficiency of an internal combustion engine is one of the most cost-effective ways to reduce life cycle-based CO2 emissions for transportation. Lean burn technology has the potential to reach high thermal efficiency if simultaneous low NOx, HC, and CO emissions can be achieved. Low NOx can be realized by ultra-lean (λ ≥ 2) spark-ignited combustion; however, the HC and CO emissions can increase due to slow flame propagation and high combustion variability. In this work, we introduce a new combustion concept called turbulent jet-controlled compression ignition, which utilizes multiple turbulent jets to ignite the mixture and subsequently triggers end gas autoignition. As a result, the ultra-lean combustion is further improved with reduced late-cycle combustion duration and enhanced HC and CO oxidation. A low-cost passive prechamber is innovatively fueled using a DI injector in the main combustion chamber through spray-guided stratification. This concept has been experimentally demonstrated as detailed in this article to achieve 47.7% peak indicated efficiency and below 1 g/kWh engine-out NOx emission with initial single-cylinder engine hardware. Further systematic combustion system optimization is underway to demonstrate state-of-the-art efficiency and emissions at a wider operating range.
提高内燃机的热效率是减少运输过程中基于生命周期的二氧化碳排放的最具成本效益的方法之一。如果能同时实现低 NOx、HC 和 CO 排放，那么稀薄燃烧技术就有可能达到很高的热效率。超精益（λ ≥ 2）火花点火燃烧可实现低氮氧化物；然而，由于火焰传播慢和燃烧变化大，HC 和 CO 排放会增加。在这项工作中，我们引入了一种新的燃烧概念，称为湍流喷射控制压缩点火，它利用多个湍流喷射点燃混合气，随后触发尾气自燃。因此，超净燃烧得到了进一步改善，燃烧后期持续时间缩短，HC 和 CO 氧化能力增强。通过喷雾引导分层，在主燃烧室中使用 DI 喷射器创新性地为低成本被动式前室提供燃料。本文详细介绍了这一概念的实验证明，在最初的单缸发动机硬件条件下，峰值指示效率达到 47.7%，发动机排出的氮氧化物排放量低于 1 克/千瓦时。目前正在对燃烧系统进行进一步的系统优化，以便在更大的工作范围内展示最先进的效率和排放量。
{"title":"Development of a Turbulent Jet-Controlled Compression Ignition Engine\u0000 Concept Using Spray-Guided Stratification for Fueling a Passive\u0000 Prechamber","authors":"Xin Yu, Anqi Zhang, Andrew Baur, Nayan Engineer, David Cleary","doi":"10.4271/03-17-04-0031","DOIUrl":"https://doi.org/10.4271/03-17-04-0031","url":null,"abstract":"Improving thermal efficiency of an internal combustion engine is one of the most\u0000 cost-effective ways to reduce life cycle-based CO2 emissions for\u0000 transportation. Lean burn technology has the potential to reach high thermal\u0000 efficiency if simultaneous low NOx, HC, and CO emissions can be achieved. Low\u0000 NOx can be realized by ultra-lean (λ ≥ 2) spark-ignited combustion; however, the\u0000 HC and CO emissions can increase due to slow flame propagation and high\u0000 combustion variability. In this work, we introduce a new combustion concept\u0000 called turbulent jet-controlled compression ignition, which utilizes multiple\u0000 turbulent jets to ignite the mixture and subsequently triggers end gas\u0000 autoignition. As a result, the ultra-lean combustion is further improved with\u0000 reduced late-cycle combustion duration and enhanced HC and CO oxidation. A\u0000 low-cost passive prechamber is innovatively fueled using a DI injector in the\u0000 main combustion chamber through spray-guided stratification. This concept has\u0000 been experimentally demonstrated as detailed in this article to achieve 47.7%\u0000 peak indicated efficiency and below 1 g/kWh engine-out NOx emission with initial\u0000 single-cylinder engine hardware. Further systematic combustion system\u0000 optimization is underway to demonstrate state-of-the-art efficiency and\u0000 emissions at a wider operating range.","PeriodicalId":47948,"journal":{"name":"SAE International Journal of Engines","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2024-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139599856","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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