ASME 2020 Internal Combustion Engine Division Fall Technical Conference最新文献

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Towards Integrated Spark and Combustion Modeling for Engines 面向发动机的火花和燃烧综合建模
ASME 2020 Internal Combustion Engine Division Fall Technical Conference Pub Date : 2020-11-04 DOI: 10.1115/icef2020-2934
Anand Karpatne, V. Subramaniam, S. Joshi, Xiao-yu Qin, D. Breden, A. Sofianopoulos, L. Raja
{"title":"Towards Integrated Spark and Combustion Modeling for Engines","authors":"Anand Karpatne, V. Subramaniam, S. Joshi, Xiao-yu Qin, D. Breden, A. Sofianopoulos, L. Raja","doi":"10.1115/icef2020-2934","DOIUrl":"https://doi.org/10.1115/icef2020-2934","url":null,"abstract":"\u0000 Combustion and emission performance of internal combustion (IC) engines depend on the ability of the ignition system to provide an ignition kernel that can successfully transition into an early flame kernel. Several key physical phenomena such as flow physics, plasma dynamics, circuit transients, and electromagnetics influence the behavior of the spark. The combustion kinetics decide the eventual transition of the spark into a self-sustaining flame kernel. The goal of this paper is to present a feasibility study involving the integration of a high-fidelity magnetohydrodynamic description of the spark physics with a finite rate chemical kinetics-based combustion model. A future goal of this proposed framework will be to model and validate a coupled ignition and combustion simulation for spark ignited engines. Two separate solvers are used to model spark physics and combustion kinetics respectively, and a coupling strategy is developed to model different aspects of physics occurring at disparate time-scales. This approach provides a physically consistent estimate of the electrical energy distribution within the spark-gap under high cross-flow velocities. When provided with certain favorable in-cylinder conditions, the spark kernel triggers self-sustained combustion.","PeriodicalId":379034,"journal":{"name":"ASME 2020 Internal Combustion Engine Division Fall Technical Conference","volume":"36 5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125558474","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}
引用次数: 0
Assessment of Hydrogen and Natural Gas Mixtures in a Large Bore Gas Engine for Power Generation 发电用大口径燃气发动机中氢气和天然气混合物的评价
ASME 2020 Internal Combustion Engine Division Fall Technical Conference Pub Date : 2020-11-04 DOI: 10.1115/icef2020-2949
Bernhard Fercher, A. Wimmer, J. Zelenka, G. Kammel, Zita Baumann
{"title":"Assessment of Hydrogen and Natural Gas Mixtures in a Large Bore Gas Engine for Power Generation","authors":"Bernhard Fercher, A. Wimmer, J. Zelenka, G. Kammel, Zita Baumann","doi":"10.1115/icef2020-2949","DOIUrl":"https://doi.org/10.1115/icef2020-2949","url":null,"abstract":"\u0000 Now more than ever there is a growing global interest to reduce greenhouse gas (GHG) emissions originating from internal combustion engines. One approach consists in the use of hydrogen instead of fossil fuels. Large bore gas engines for power generation are often fueled by gases with high methane content. Relative to natural gas-fueled engines, the power densities of premixed or port-fuel-injected hydrogen engines are limited due to low volumetric efficiencies and moreover by occurring irregular combustion events (knocking, backfire).\u0000 The paper presents results from experimental investigations of the impact of different hydrogen substitution rates in natural gas on performance, emissions and operating limits on a single cylinder research engine. The engine is representative for a large bore gas engine for power generation and operates using an open chamber combustion concept with lean mixtures.\u0000 Essentially, THC, CO2 and CO emissions decrease with rising hydrogen content of the fuel gas. Even with low concentrations of hydrogen in the fuel gas, significant reductions in THC emissions could be demonstrated. Usually NOX emissions will rise with unchanged operating parameters. However, if excess-air ratio and spark timing are adjusted, a net reduction of NOX emissions can be achieved while the impact on brake thermal efficiency is small.\u0000 Furthermore, the paper outlines potential mitigation strategies to expand the operational limits with respect to power density with high hydrogen substitution rates.","PeriodicalId":379034,"journal":{"name":"ASME 2020 Internal Combustion Engine Division Fall Technical Conference","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116051141","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}
引用次数: 2
Assessment of Spark, Corona, and Plasma Ignition Systems for Gasoline Combustion 汽油燃烧的火花、电晕和等离子点火系统的评估
ASME 2020 Internal Combustion Engine Division Fall Technical Conference Pub Date : 2020-11-04 DOI: 10.1115/icef2020-3034
Sayan Biswas, Isaac W. Ekoto, D. Singleton, Kristapher Mixell, Ford Patrick
{"title":"Assessment of Spark, Corona, and Plasma Ignition Systems for Gasoline Combustion","authors":"Sayan Biswas, Isaac W. Ekoto, D. Singleton, Kristapher Mixell, Ford Patrick","doi":"10.1115/icef2020-3034","DOIUrl":"https://doi.org/10.1115/icef2020-3034","url":null,"abstract":"\u0000 In the present study, the performance and emissions characteristics of three low-temperature plasma (LTP) ignition systems were compared to a more conventional strategy that utilized a high-energy coil (93 mJ) inductive spark igniter. All experiments were performed in a single-cylinder, optically accessible, research engine. In total, three different ignition systems were evaluated: (1) an Advanced Corona Ignition System (ACIS) that used radiofrequency (RF) discharges (0.5–2.0 ms) to create corona streamer emission into the bulk gas via four-prong electrodes, (2) a Barrier Discharge Igniter (BDI) that used the same RF discharge waveform to produce surface LTP along an electrode encapsulated completely by the insulator, and (3) a Nanosecond Repetitive Pulse Discharge (NRPD) ignition system that used a non-resistor spark plug and positive DC pulses (∼10 nanoseconds width) for a fixed frequency of 100 kHz, with the operating voltage-controlled to avoid LTP transition to breakdown. For the LTP ignition systems, pulse energy and duration (or number) were varied to optimize efficiency. A single 1300 revolutions per minute (rpm), 3.5 bar indicated mean effective pressure (IMEP) homogeneous operating point was evaluated. Equivalence ratio (ϕ) sweeps were performed that started at stoichiometric conditions and progressed toward the lean limit.\u0000 Both the ACIS and NRPD ignition systems extended the lean limit (where the variation of IMEP < 3%) limit (ϕ = 0.65) compared to the inductive spark (ϕ = 0.73). The improvement was attributed to two related factors. For the ACIS, less spark retard was required as compared to spark ignition due to larger initial kernel volumes produced by four distinct plasma streamers that emanate into the bulk gas. For the NRPD ignition system, additional pulses were thought to add expansion energy to the initial kernel. As a result, initial flame propagation was accelerated, which accordingly shortens early burn rates.","PeriodicalId":379034,"journal":{"name":"ASME 2020 Internal Combustion Engine Division Fall Technical Conference","volume":"14 5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116548459","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}
引用次数: 3
An Experimental and Numerical Study of a Hydrogen Fueled, Directly Injected, Heavy Duty Engine at Knock-Limited Conditions 限敲条件下氢燃料直喷重型发动机的试验与数值研究
ASME 2020 Internal Combustion Engine Division Fall Technical Conference Pub Date : 2020-11-04 DOI: 10.1115/icef2020-2920
J. Mortimer, Stephen Yoannidis, F. Poursadegh, Zhewen Lu, M. Brear, Yi Yang, D. Etherington, M. Heijkoop, J. Lacey
{"title":"An Experimental and Numerical Study of a Hydrogen Fueled, Directly Injected, Heavy Duty Engine at Knock-Limited Conditions","authors":"J. Mortimer, Stephen Yoannidis, F. Poursadegh, Zhewen Lu, M. Brear, Yi Yang, D. Etherington, M. Heijkoop, J. Lacey","doi":"10.1115/icef2020-2920","DOIUrl":"https://doi.org/10.1115/icef2020-2920","url":null,"abstract":"\u0000 This paper presents an experimental and numerical study of a directly injected, spark-ignited (DI SI), heavy duty hydrogen fueled engine at knock-limited conditions. The impact of air-fuel ratio and ignition timing on engine performance is first investigated experimentally. Two-zone combustion modeling of the hydrogen fueled cylinder is then used to infer burn profiles and unburned, end-gas conditions using the measured in-cylinder pressure traces. Simulation of the autoignition chemistry in this end-gas is then undertaken to identify key parameters that are likely to impact knock-limited behavior.\u0000 The experiments demonstrate knock-limited performance on this high compression ratio engine over a wide range of air-fuel ratios, λ. Other trends with λ are qualitatively similar to those shown in previous studies of hydrogen fueled engines. Kinetic simulations then suggest that some plausible combination of residual nitric oxide from previous cycles and locally high charge temperatures at intake valve closing can lead to autoignition at the knock-limited conditions identified in the experiments. This prompts a parametric study that shows how increased λ makes hydrogen less likely to autoignite, and suggests options for the design of high efficiency, directly injected, hydrogen fueled engines.","PeriodicalId":379034,"journal":{"name":"ASME 2020 Internal Combustion Engine Division Fall Technical Conference","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129747872","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}
引用次数: 3
Design, Actuation, Experimental Setup and Testing of a 4-Cylinder Gasoline Spark Ignited Variable Compression Ratio Engine 四缸汽油火花点燃可变压缩比发动机的设计、驱动、实验设置和测试
ASME 2020 Internal Combustion Engine Division Fall Technical Conference Pub Date : 2020-11-04 DOI: 10.1115/icef2020-2960
T. Miller, J. Duncan, W. Hensley, J. E. Beard, J. Worm, J. Naber
{"title":"Design, Actuation, Experimental Setup and Testing of a 4-Cylinder Gasoline Spark Ignited Variable Compression Ratio Engine","authors":"T. Miller, J. Duncan, W. Hensley, J. E. Beard, J. Worm, J. Naber","doi":"10.1115/icef2020-2960","DOIUrl":"https://doi.org/10.1115/icef2020-2960","url":null,"abstract":"\u0000 The thermal efficiency of an Otto cycle engine is directly related to the compression ratio (CR). However, in a spark-ignited engine, the CR is often restricted by full load knock, thus limiting part load efficiency. A proof of concept design and experimental study has been conducted on a 4-cylinder naturally aspirated spark-ignited (SI) engine whereby a four-bar linkage mechanism has been implemented to vary the CR. The base engine selected was a production 2.0L GM-LNF SI 4-cylinder engine with a stock CR of 9.2:1 and with a bore and stroke of 86mm and 86mm, respectively. The engine was modified to allow the centerline axis of rotation of the crankshaft to translate in an arc about a fixed point. With the use of the four-bar mechanism, and larger dome volume pistons, a range of 8:1 to 11.5:1 CR was achieved.\u0000 The prototype VCR engine was tested and analyzed at three different CR’s at a fixed load of 600 kPa net indicated mean effective pressure gross (IMEPGROSS) at an engine speed of 1000 revolutions per minute (RPM). At this condition, a sweep of combustion phasing was conducted. with a stoichiometric air to fuel mixture for each case. The CR’s selected for engine testing were 8.7:1, 10.2:1, and 11.1:1. The processed data includes averaged cycle analysis of each of the test conditions including combustion phasing, combustion duration, and cycle variation. The combustion data was also analyzed to determine overall heat release, indicated gross, net, pumping mean effective pressures, and indicated fuel conversion efficiency for each of the CR’s. The studies show an indicated fuel conversion efficiency of 31.2% for the 8.7:1 CR. As the CR was increased to 10.2:1 and 11.1:1 the relative increase in efficiency was 7.1% and 9.7% respectively at MBT combustion phasing.","PeriodicalId":379034,"journal":{"name":"ASME 2020 Internal Combustion Engine Division Fall Technical Conference","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129166250","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}
引用次数: 1
Experimental and Numerical Analysis on the Influence of Direct Fuel Injection Into O2-Depleted Environment of a GDI-HCCI Engine GDI-HCCI发动机零氧环境下燃油直喷影响的实验与数值分析
ASME 2020 Internal Combustion Engine Division Fall Technical Conference Pub Date : 2020-11-04 DOI: 10.1115/icef2020-2909
R. Sok, Jin Kusaka
{"title":"Experimental and Numerical Analysis on the Influence of Direct Fuel Injection Into O2-Depleted Environment of a GDI-HCCI Engine","authors":"R. Sok, Jin Kusaka","doi":"10.1115/icef2020-2909","DOIUrl":"https://doi.org/10.1115/icef2020-2909","url":null,"abstract":"\u0000 Injected gasoline into the O2-depleted environment in the recompression stroke can be converted into light hydrocarbons due to thermal cracking, partial oxidation, and water-gas shift reaction. These reformate species influence the combustion phenomena of gasoline direct injection homogeneous charge compression ignition (GDI-HCCI) engines. In this work, a production-based single-cylinder research engine was boosted to reach IMEPn = 0.55 MPa in which its indicated efficiency peaks at 40–41%. Experimentally, the main combustion phases are advanced under single-pulse direct fuel injection into the negative valve overlap (NVO) compared with that of the intake stroke. NVO peak in-cylinder pressures are lower than that of motoring, which emphasizes that endothermic reaction occurs during the interval. Low O2 concentration could play a role in this evaporative charge cooling effect. This phenomenon limits the oxidation reaction, and the thermal effect is not pronounced. For understanding the recompression reaction phenomena, 0D simulation with three different chemical reaction mechanisms is studied to clarify that influences of direct injection timing in NVO on combustion advancements are kinetically limited by reforming. The 0D results show the same increasing tendencies of classical reformed species of rich-mixture such as C3H6, C2H4, CH4, CO, and H2 as functions of injection timings. By combining these reformed species into the main fuel-air mixture, predicted ignition delays are shortened.\u0000 The effects of the reformed species on the main combustion are confirmed by 3D-CFD calculation, and the results show that OH radical generation is advanced under NVO fuel injection compared with that of intake stroke conditions thus earlier heat release and cylinder pressure are noticeable. Also, parametric studies on injection pressure and double-pulse injections on engine combustion are performed experimentally.","PeriodicalId":379034,"journal":{"name":"ASME 2020 Internal Combustion Engine Division Fall Technical Conference","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134290089","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}
引用次数: 0
Validation of Species-Based Extended Coherent Flamelet Model in a Large Eddy Simulation of a Homogeneous Charge Spark Ignition Engine 基于物种的扩展相干小火焰模型在均匀装药火花点火发动机大涡模拟中的验证
ASME 2020 Internal Combustion Engine Division Fall Technical Conference Pub Date : 2020-11-04 DOI: 10.1115/icef2020-2942
Y. See, M. Wang, J. Bohbot, O. Colin
{"title":"Validation of Species-Based Extended Coherent Flamelet Model in a Large Eddy Simulation of a Homogeneous Charge Spark Ignition Engine","authors":"Y. See, M. Wang, J. Bohbot, O. Colin","doi":"10.1115/icef2020-2942","DOIUrl":"https://doi.org/10.1115/icef2020-2942","url":null,"abstract":"\u0000 The Species-Based Extended Coherent Flamelet Model (SB-ECFM) was developed and previously validated for 3D Reynolds-Averaged Navier-Stokes (RANS) modeling of a spark-ignited gasoline direct injection engine. In this work, we seek to extend the SB-ECFM model to the large eddy simulation (LES) framework and validate the model in a homogeneous charge spark-ignited engine. In the SB-ECFM, which is a recently developed improvement of the ECFM, the progress variable is defined as a function of real species instead of tracer species. This adjustment alleviates discrepancies that may arise when the numerical treatment of real species is different than that of the tracer species. Furthermore, the species-based formulation also allows for the use of second-order numeric, which can be necessary in LES cases. The transparent combustion chamber (TCC) engine is the configuration used here for validating the SB-ECFM. It has been extensively characterized with detailed experimental measurements and the data are widely available for model benchmarking. Moreover, several of the boundary conditions leading to the engine are also measured experimentally. These measurements are used in the corresponding computational setup of LES calculations with SB-ECFM. Since the engine is spark ignited, the Imposed Stretch Spark Ignition Model (ISSIM) is utilized to model this physical process. The mesh for the current study is based on a configuration that has been validated in a previous LES study of the corresponding motored setup of the TCC engine. However, this mesh was constructed without considering the additional cells needed to sufficiently resolve the flame for the fired case. Thus, it is enhanced with value-based Adaptive Mesh Refinement (AMR) on the progress variable to better capture the flame front in the fired case. As one facet of model validation, the ensemble average of the measured cylinder pressure is compared against the LES/SB-ECFM prediction. Secondly, the predicted cycle-to-cycle variation by LES is compared with the variation measured in the experimental setup. To this end, the LES computation is required to span a sufficient number of engine cycles to provide statistical convergence to evaluate the coefficient of variation (COV) in peak cylinder pressure. Due to the higher computational cost of LES, the runtime required to compute a sufficient number of engine cycles sequentially can be intractable. The concurrent perturbation method (CPM) is deployed in this study to obtain the required number of cycles in a reasonable time frame. Lastly, previous numerical and experimental analyses of the TCC engine have shown that the flow dynamics at the time of ignition is correlated with the cycle-to-cycle variability. Hence, similar analysis is performed on the current simulation results to determine if this correlation effect is well-captured by the current modeling approach.","PeriodicalId":379034,"journal":{"name":"ASME 2020 Internal Combustion Engine Division Fall Technical Conference","volume":"279 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127799530","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}
引用次数: 0
Infrared Experimental Investigations on the Effects of Direct Water Injection in an Optical Engine 光学发动机直接注水效果的红外实验研究
ASME 2020 Internal Combustion Engine Division Fall Technical Conference Pub Date : 2020-11-04 DOI: 10.1115/icef2020-2912
Amer Farhat, Taewon Kim, Ming-Chia Lai, M. Jansons, Xin Yu
{"title":"Infrared Experimental Investigations on the Effects of Direct Water Injection in an Optical Engine","authors":"Amer Farhat, Taewon Kim, Ming-Chia Lai, M. Jansons, Xin Yu","doi":"10.1115/icef2020-2912","DOIUrl":"https://doi.org/10.1115/icef2020-2912","url":null,"abstract":"\u0000 The effects of water injection on combustion characteristics were investigated in an optically-accessible light-duty engine retrofitted with a side-mounted water injector. The main objective was to study the effect of water injection on autoignition and subsequent combustion process in compression ignition engines. Numerical zero-dimensional simulations were first performed to separate the thermal from the kinetic effects of water on the ignition delay and maximum temperature reached by a reacting mixture. Then, experimental investigations were performed at different intake temperatures and levels of thermal stratification achieved via direct water injection. Combustion analysis was performed on cylinder pressure data to study the effect of water injection on the overall combustion process. Infrared imaging was performed to provide insight to how water injection and the resulting water distributions affect thermal stratification, autoignition, and combustion characteristics. A new method in quantifying the water distributions is suggested. The results show that the overall level of stratification is sensitive to water injection timing and pressure, where increased water injection pressures and advanced injection timings result in more homogenous distributions. Moreover, water injection was found to affect the location of ignition kernels and the local presence of water suppressed ignition. The level of water stratification was also observed to affect the combustion process, where more homogenous distributions lost their ability to influence ignition locations. Finally, the infrared images showed high levels of residual water left over from prior water-injected cycles, suggesting that hardware configurations and injection strategies must be optimized to avoid wall wetting for stable engine operation.","PeriodicalId":379034,"journal":{"name":"ASME 2020 Internal Combustion Engine Division Fall Technical Conference","volume":"357 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115985160","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}
引用次数: 0
Effect of Split Injection Timing on Combustion and Emissions of a DISI Optical Engine Under Lean Burn Condition 稀燃条件下分离式喷油时机对DISI光学发动机燃烧与排放的影响
ASME 2020 Internal Combustion Engine Division Fall Technical Conference Pub Date : 2020-11-04 DOI: 10.1115/icef2020-2961
Zhe Sun, Mingli Cui, Hongyu Wang, M. Nour, Xuesong Li, Min Xu, D. Hung
{"title":"Effect of Split Injection Timing on Combustion and Emissions of a DISI Optical Engine Under Lean Burn Condition","authors":"Zhe Sun, Mingli Cui, Hongyu Wang, M. Nour, Xuesong Li, Min Xu, D. Hung","doi":"10.1115/icef2020-2961","DOIUrl":"https://doi.org/10.1115/icef2020-2961","url":null,"abstract":"\u0000 Lean combustion has proven to be an effective way to improve the efficiency and emissions of the direct injection spark ignition (DISI) engine. However, one of the main problems at the lean stability limit is the major decrease in flame temperature due to dilution, resulting in a low laminar flame speed, especially under low-speed engine operating conditions. The split injection is a potential technology to realize proper air-fuel mixing and achieve different spray distribution that can help in solving such problems. In this study, split injections with different secondary injection timings were tested to achieve homogeneous and homogeneous-stratified modes in a DISI optical engine under lean-burn mode. The split ratio of each strategy was 1:1. The engine was operated at 800 rpm, and a high-energy ignition system was utilized to realize lean combustion at a lambda of 1.55. Engine combustion performance and emissions were tested while performing high-speed color recording to study the characteristics of flame chemiluminescence through a quartz piston combined with a 45-degree mirror installed below. Flame structure during various combustion phases was compared under different selected conditions based on a digital image processing technique. The results show that the pressure and emissions vary with the second injection timing. Proper control of the split injection timing can improve lean combustion performance, including faster flame speed, increased indicated mean effective pressure (IMEP), and lower harmful emissions. Poor fuel evaporation and soot generation from spatial hot spots in the combustion process of split injection are the major challenges for further improvement.","PeriodicalId":379034,"journal":{"name":"ASME 2020 Internal Combustion Engine Division Fall Technical Conference","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128621869","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}
引用次数: 2
A Multi-Wavelength Extinction Imaging Diagnostic for Quantifying Diesel Spray Mixing at Engine-Relevant Conditions 多波长消光成像诊断在发动机相关条件下量化柴油喷雾混合
ASME 2020 Internal Combustion Engine Division Fall Technical Conference Pub Date : 2020-11-04 DOI: 10.1115/icef2020-2972
C. Godbold, F. Poursadegh, O. Bibik, Carlos De La Camara Castillo, C. Genzale
{"title":"A Multi-Wavelength Extinction Imaging Diagnostic for Quantifying Diesel Spray Mixing at Engine-Relevant Conditions","authors":"C. Godbold, F. Poursadegh, O. Bibik, Carlos De La Camara Castillo, C. Genzale","doi":"10.1115/icef2020-2972","DOIUrl":"https://doi.org/10.1115/icef2020-2972","url":null,"abstract":"\u0000 The mixing of fuel and air in the combustion chamber of an IC engine is crucial to emissions formation. Therefore, developing effective diagnostic techniques for measuring mixing is critical for progressing IC engines. Existing methodologies for the optical measurement of air-fuel mixing, including Rayleigh scattering and Laser Induced Fluorescence (LIF), have demonstrated various diagnostic-implementation challenges, high uncertainties under engine-relevant environments, and strong interferences from the liquid spray which prevents their use in near-spray measurements. This work presents the use of an alternative approach based on a laser-absorption/scattering technique called Ultraviolet-Visible Diffuse Back-Illumination (UV-Vis DBI) to quantify local equivalence ratio in a vaporizing diesel spray. Ultraviolet and visible light are generated using a ND:YAG pumped frequency-doubled tunable dye laser operating at 9.9 kHz. The simultaneous UV-Visible illumination is used to back-illuminate a vaporizing diesel spray, and the resulting extinction of each signal is recorded by a pair of high-speed cameras. Using an aromatic tracer (naphthalene, BP = 218 °C) in a base fuel of dodecane (BP = 215–217 °C), the UV illumination (280 nm) is absorbed along the illumination path through the spray, yielding a projected image of line-of-sight optical depth that is proportional to the path-average fuel vapor concentration in the vapor region of the spray. The visible illumination is chosen at a non-absorbing wavelength (560 nm), such that the light extinction is only due to liquid scattering, yielding a projected image of the liquid spray. A key advantage of the method is that the absorption coefficient of the selected tracer is relatively independent of temperature and pressure for 280-nm illumination, reducing measurement uncertainties at engine-relevant conditions. Measurements are also achievable in near-spray vapor regions since there is no mie-scattering interference from the liquid spray. The diagnostic is applied to measure the fuel-air mixing field of a diesel spray produced by a Bosch CRI3-20 ks1.5 single-orifice injector (90 μm diameter) similar to ECN Spray A. Measurements are conducted in a non-reacting high-pressure and temperature nitrogen environment using a constant-flow, optically-accessible spray chamber operating at 60 bar and 900 K. The results are evaluated against existing ECN mixing measurements based on Rayleigh scattering. The diagnostic yields centerline and radial mixture fraction measurements that match the ECN Rayleigh measurements within uncertainty bounds.","PeriodicalId":379034,"journal":{"name":"ASME 2020 Internal Combustion Engine Division Fall Technical Conference","volume":"62 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126659411","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}
引用次数: 0
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