Volume 2: Emissions Control Systems; Instrumentation, Controls, and Hybrids; Numerical Simulation; Engine Design and Mechanical Development最新文献

{"title":"Numerical Study on Evaporation of Lubricating Oil Droplets Under Natural Gas Engine Conditions","authors":"L. Feng, Zixin Wang, Ping Yi, W. Gong, Jingchen Cui, Lei Chen, Jiang-ping Tian, Wuqiang Long","doi":"10.1115/ICEF2018-9639","DOIUrl":"https://doi.org/10.1115/ICEF2018-9639","url":null,"abstract":"The distribution of lubricating oil droplets in cylinder is one of main causes of abnormal combustion of natural gas engines. The evaporation of lubricating oil droplet is one of the key sub-processes controlling its auto-ignition event. The components of lubricating oil with different carbon number (16–50) shows significantly different evaporation and ignition characteristics from gasoline and diesel fuels. Even though there are many evaporation models focusing on the evaporation behaviors of multi-component droplets, most of them are limited to the liquid fuels, which are composed by more volatile hydrocarbons. Therefore, understanding the evaporation characteristics of lubricating oil droplets is very important for investigating the mechanism of abnormal combustion of natural gas engines. In this study, a multi-component evaporation model for lubricating oil was developed, which considers several key characteristics in the droplet evaporation process, including the finite heat conduction and limited mass diffusion in liquid phase, multi-component diffusion in gas phase, real vapor-liquid equilibrium at the droplet interface, as well as the nitrogen quantity dissolved in liquid phase. The simulation results by this model were compared with experimental results, and good agreements have been achieved. Then, this model was used to study the evaporation behaviors of different hydrocarbon droplets, including lubricating oil droplet. The influences of ambient temperatures and pressures, as well as methane concentration on evaporation characteristics (namely the heat up period, average evaporation rate, and droplet lifetime) were investigated. The results show that both heat up period and evaporation rate of lubricating oil droplets increase as the methane concentration increases. Besides, the droplet lifetime monotonically decreases as the ambient pressure decreases. This is different from the diesel and gasoline droplets, for which the effects of pressure on the droplet evaporation behaviors are depended on the ambient temperature.","PeriodicalId":448421,"journal":{"name":"Volume 2: Emissions Control Systems; Instrumentation, Controls, and Hybrids; Numerical Simulation; Engine Design and Mechanical Development","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128160563","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}

{"title":"Modular 9.0L and 4.5L Non-Road Spark-Ignited Engines for Power Generation","authors":"A. Gillette, J. Dees, John M. Crudden, Anthony Petcoff","doi":"10.1115/ICEF2018-9616","DOIUrl":"https://doi.org/10.1115/ICEF2018-9616","url":null,"abstract":"Following the successful commercial use of a 9.0L, V-8 automotive-derivative engine for stationary power generation, a new 4.5L, four-cylinder engine has been developed utilizing a modular family design approach. Substantial commonality of power cylinder components has been achieved including the complete power cylinder and cylinder head. This paper describes the design and development approach to the engine family.\u0000 These spark-ignited engines are typically used for standby emergency power and demand response applications utilizing commercial grade natural gas or propane. Driving a synchronous electrical generator operating at 60 HZ or 50Hz, engine speeds are either 1800 rpm/3600 rpm or 1500 rpm/3000 rpm respectively, depending upon selection of either a 2-pole or 4-pole alternating current generator. Designed for stoichiometric combustion, the engine configurations can include naturally-aspirated, turbocharged or turbocharged and after-cooled versions. Depending upon end-use applications, exhaust emissions technology and regulatory compliance can be met solely through engine calibration or inclusion of a 3-way catalyst with active air-fuel ratio control.\u0000 Since the 9.0L engine version was successfully introduced in 2012, significant efforts have been undertaken to achieve commonality of desired features between the existing veeengine and the future in-line versions, including optimization of performance characteristics in consideration of future power rating structures. Starting from 9.0L commercial introduction, the content herein specifically describes the development of the new 4.5L engine with regard to design and analysis.","PeriodicalId":448421,"journal":{"name":"Volume 2: Emissions Control Systems; Instrumentation, Controls, and Hybrids; Numerical Simulation; Engine Design and Mechanical Development","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133473291","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}

{"title":"Predictive CFD Modeling of Diesel Engine Combustion Using an Efficient Workflow Based on Tabulated Chemistry","authors":"F. Tap, C. Meijer, D. Goryntsev, A. Starikov, Mijo Tvrdojevic, P. Priesching","doi":"10.1115/ICEF2018-9758","DOIUrl":"https://doi.org/10.1115/ICEF2018-9758","url":null,"abstract":"The use of 3D CFD combustion models based on tabulated chemistry is becoming increasingly popular. Especially the runtime benefit is attractive, as the tabulated chemistry method allows to include state-of-the-art chemical reaction schemes in CFD simulations. In this work, the Tabkin FGM combustion model in AVL FIRE™ is used to assess the predictivity on a large database of a light-duty Diesel engine measurements. The AVL TABKIN™ software is used to create the chemistry look-up tables for the Tabkin FGM model.\u0000 The TABKIN software has been extended with the kinetic soot model, where the soot mass fraction calculation is done during the chemistry tabulation process, as well as an NO model using a second progress variable. From recent validation studies, a best-practice and nearly automated workflow has been derived to create the look-up tables for Diesel engine applications based on minimal input. This automated modeling workflow is assessed in the present study.\u0000 A wide range of parameter variations are investigated for 5 engine load points, with and without EGR, in total 186 cases. This large number of CFD simulations is run in an automated way and the parameters of the CFD sub-models are kept equal as well as all numerical settings.\u0000 Results are presented for combustion and emissions (NO and soot). Combustion parameters and NO emissions correlate very well to the experimental database with R2 values above 0.95. Soot predictions give order-of-magnitude agreement for most of the cases; the trend however is not always respected, which limits the overall correlation for all cases together, as reported by other authors. Further fundamental research on modeling soot formation and oxidation process remains required to improve the models. In terms of CPU time, the present study was executed on an off-the-shelf HPC cluster, using 8 CPU cores per case and requiring around 3 hrs of wall-time per case, e.g. such a large set of calculations can be simulated overnight on a standard HPC cluster.","PeriodicalId":448421,"journal":{"name":"Volume 2: Emissions Control Systems; Instrumentation, Controls, and Hybrids; Numerical Simulation; Engine Design and Mechanical Development","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116616495","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}

{"title":"Combustion Variability Model for Control of Injection Timing for Diesel Exhaust Heating","authors":"Mitchell Bieniek, A. Stefanopoulou, J. Hoard, B. Fulton, M. V. Nieuwstadt","doi":"10.1115/ICEF2018-9638","DOIUrl":"https://doi.org/10.1115/ICEF2018-9638","url":null,"abstract":"Diesel engine emission cycle data shows that major portions of cycle emissions are produced at the beginning of the test, when the aftertreatment is not at operational temperature (prior to “light-off”) [1]. To reduce diesel emissions, aggressive combustion phasing retard via injection timing can be used to achieve faster aftertreatment light-off, but this method is limited because of vibration and harshness concerns associated with the combustion variability induced by the late combustion phasing. In order to achieve aggressive exhaust heating while mitigating combustion variability concerns, the premise of controlling combustion variability is explored. In particular, a controller will use real-time measurements of combustion features and control injection timing to maintain an acceptable level of combustion variability. The closed loop controller tuning requires an understanding of combustion variability behavior as a function of combustion phasing retard. The characterization of combustion variability using engine experiments is presented, and the findings are used to develop a control-oriented combustion variability model consisting of regressions of the statistics of IMEP as a function of fuel and timing offsets.","PeriodicalId":448421,"journal":{"name":"Volume 2: Emissions Control Systems; Instrumentation, Controls, and Hybrids; Numerical Simulation; Engine Design and Mechanical Development","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133779109","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}

{"title":"Turbulent Reactive Flow Modeling in Engines: A Robust and Accurate Toolkit/Software for Simulating Engine Dynamics","authors":"D. Carrington, J. Waters","doi":"10.1115/ICEF2018-9552","DOIUrl":"https://doi.org/10.1115/ICEF2018-9552","url":null,"abstract":"The Los Alamos turbulent reactive flow researchers, our modelers and simulation code developers have succeeded in providing the engine research and development community an encompassing, robust, accurate and easy to use software for engine modeling or simulations. This software is now known as the FEARCE Toolkit.\u0000 In this paper we discuss the physics present in the engine by discussion the methods we’ve employed to solve the model equations within the toolkit. Provided are background on what has been developed recently at LANL for internal combustion engine modeling.","PeriodicalId":448421,"journal":{"name":"Volume 2: Emissions Control Systems; Instrumentation, Controls, and Hybrids; Numerical Simulation; Engine Design and Mechanical Development","volume":"66 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124538069","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}

{"title":"Effects of Injection Pressure on Emission and Components of Particulate Matter From Marine Diesel Engine","authors":"Mayuko Nakamura, A. Ohashi, Y. Niki, A. Masuda, C. Takahashi","doi":"10.1115/ICEF2018-9644","DOIUrl":"https://doi.org/10.1115/ICEF2018-9644","url":null,"abstract":"Reduction of particulate matter (PM) is important issues even for shipping industry since PM harms the environment and human health. In order to reduce PM from marine diesel engines, we focused on components forming PM, elemental carbon (EC), organic carbon (OC), sulfate, and “others” (nitrate, bound water associated with sulfate, metal, ash and hydrogen associated with OC), and investigated the reduction effect of each component by changing fuel injection pressure of a four-stroke marine diesel engine at the two engine load points of 25% and 50%. At 50% load, the PM emissions decreased with increasing the fuel injection pressure, the reduction in the PM emissions which reflected the decrease in EC. At 25% load, the PM emissions did not decrease simply with the injection pressure since OC, sulfate, “others” components in addition to EC contributed to the injection pressure dependence of PM. The results suggest that behaviors of each component of PM should be grasped to achieve the appropriate reduction method of PM.","PeriodicalId":448421,"journal":{"name":"Volume 2: Emissions Control Systems; Instrumentation, Controls, and Hybrids; Numerical Simulation; Engine Design and Mechanical Development","volume":"57 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124748717","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}

{"title":"Piston Rings Friction Comparison in a Free Piston and Conventional Crankshaft Engines","authors":"M. Bade, N. Clark, T. Musho, P. Famouri","doi":"10.1115/ICEF2018-9774","DOIUrl":"https://doi.org/10.1115/ICEF2018-9774","url":null,"abstract":"The conventional internal combustion engines driven by crankshafts and connecting rod mechanisms are restrained by combustion, thermal and mechanical inefficiencies. The Oscillating Free Piston Linear Engine Alternator (OFPLEA) produces electric power with no need to modify the reciprocating motion to rotary motion. In the most common geometry it consists of a linear alternator driven cyclically by one or two internal combustion engines. With the elimination of crankshaft mechanism linkages, the free piston engine offers potential benefits over crankshaft engines in terms of total mechanical losses. A significant proportion of 5% to 12% of total fuel energy in conventional engines is consumed to overcome the frictional losses. This research investigation addresses an analytical and numerical model to simulate the tribological performance of piston rings in an OFPLEA engine. The results are then compared with results from an equivalent conventional crankshaft driven engine. This axisymmetric, mixed lubrication tribological model is developed on the hydrodynamic process defined by Patir and Cheng’s modified Reynolds equation and an asperity contact process as defined by Greenwood and Tripp’s rough surface dry contact model. The asperity contact pressure distribution, hydrodynamic pressure distribution, lubricant oil film thickness, frictional force and frictional power losses are calculated using an explicit finite difference approach. In the absence of spring-dominated OFPLEA system, dissimilarity in the piston motion profile for compression and power stroke exhibited two different oil film thickness peaks. Whereas a similar oil film thickness peaks are observed for conventional engine due to the controlled and stable operation maintained by crankshaft mechanism. The simulation results state that the frictional losses due to piston ring - cylinder liner contact are found to be lower for a free piston engine than for those of a corresponding crankshaft engine. The simulated piston ring frictional power losses are found to be 342.8 W for the OFPLEA system and 382.6 W for the crankshaft engine. Further, an overall system efficiency improvement of 0.6 % is observed for an OFPLEA engine due to these reduced frictional losses from piston rings.","PeriodicalId":448421,"journal":{"name":"Volume 2: Emissions Control Systems; Instrumentation, Controls, and Hybrids; Numerical Simulation; Engine Design and Mechanical Development","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121903512","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}

{"title":"Numerical Studies of Combustion Recession on ECN Diesel Spray A","authors":"Xiaohan Fang, R. Ismail, M. Davy, J. Camm","doi":"10.1115/ICEF2018-9597","DOIUrl":"https://doi.org/10.1115/ICEF2018-9597","url":null,"abstract":"It is known that low-temperature combustion (LTC) strategies can help simultaneously reduce nitrogen oxides (NOx) and particulate matter (PM) emissions from diesel engines to very low levels. However, it is also known that LTC may cause emissions of unburned hydrocarbons (UHC) to rise — especially in low load operating conditions. Recent studies indicate that end-of-injection (EOI) processes may support ignition recession back to injector nozzle thereby helping to reduce these emissions. This paper contributes to the physical understanding of this EOIphe-nomenon, combustion recession, using computational fluid dynamics studies at LTC conditions. Simulations are performed on a single-hole injection of n-dodecane under a range of Engine Combustion Network’s “Spray A” conditions. The primary objective of this paper is to assess the ability of a Flamelet Generated Manifold (FGM) combustion model to predict and characterize combustion recession. First, a baseline condition FGM simulation is compared with two other combustion models namely the Well Stirred model (WSR), the Representative Interactive Flamelet model (RIF) using the commercially-available CFD solver, CONVERGE. Further studies were carried out for FGM model alone including: varying ambient temperature conditions and chemical mechanisms. Two chemical kinetics mechanisms with low temperature chemistry for n-dodecane are employed to help to predict the occurrence of combustion recession. All simulations are performed under the Reynolds-Averaged Navier-Stokes (RANS) framework in a grid-converged Lagrangian spray scenario. The simulation of combustion recession is qualitatively validated against experimental data from literature and the efficacy of each model in predicting combustion recession is evaluated. Overall, it was found that the FGM model was able to capture the combustion recession phenomenon well — showing particular strength in predicting distinct auto-ignition events in the near nozzle region.","PeriodicalId":448421,"journal":{"name":"Volume 2: Emissions Control Systems; Instrumentation, Controls, and Hybrids; Numerical Simulation; Engine Design and Mechanical Development","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115547610","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}

{"title":"A Signal Processing of In-Cylinder Pressure for the Resonant Frequency Prediction of Combustion Process in Diesel Engines","authors":"Cheng Ximing, L. Long, Jiguang Zhang, J. Du","doi":"10.1115/ICEF2018-9534","DOIUrl":"https://doi.org/10.1115/ICEF2018-9534","url":null,"abstract":"The combustion resonance is a focal point of the analysis of combustion and thermodynamic processes in diesel engines, such as detecting ‘knock’ and predicting combustion noise. Combustion resonant frequency is also significant for the estimation of in-cylinder bulk gas temperature and trapped mass. Normally, the resonant frequency information is contained in in-cylinder pressure signals. Therefore, the in-cylinder pressure signal processing is used for resonant frequency calculation. Conventional spectral analyses, such as FFT (Fast Fourier transform), are unsuitable for processing in-cylinder pressure signals because of its non-stationary characteristic. Other approaches to deal with non-stationary signals are Short-Time Fourier Transform (STFT) and Continue Wavelet Transform (CWT). However, the choice of size and shape of window for STFT and the selection of wavelet basis for CWT are totally empirical, which is the limit for precisely calculating the resonant frequency. In this study, an approach based on Empirical Wavelet Transform (EWT) and Hilbert Transform (HT) is proposed to process in-cylinder pressure signals and extract resonant frequencies. In order to decompose in-cylinder pressure spectrum precisely, the EWT are applied for separating the frequency band corresponding combustion resonance mode from other irrelevant modes adaptively. The signals containing combustion resonant mode is processed by HT, so that the instantaneous resonant frequency and amplitude can be extracted. Validation is performed by four in-cylinder pressure signals with different injection timing. And the effects of injection timing on resonant frequency are discussed.","PeriodicalId":448421,"journal":{"name":"Volume 2: Emissions Control Systems; Instrumentation, Controls, and Hybrids; Numerical Simulation; Engine Design and Mechanical Development","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130844702","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}

{"title":"A Conceptual Study for the Smallest Possible Diesel Engine: Potential and Limitations","authors":"Yousef Jeihouni, Avnish Dhongde, H. Sankhla, M. Franke","doi":"10.1115/ICEF2018-9522","DOIUrl":"https://doi.org/10.1115/ICEF2018-9522","url":null,"abstract":"Downsizing of engines is a major area of interest in the combustion engines sector due to a variety of reasons, chief among which is the CO2 emission reduction due to increased power to weight ratio. Furthermore, the introduction of various auxiliary devices into an automotive product, as well as increased acoustic insulation, necessitate continuous trimming of the engine packaging space. In this paper, the potential and limitations of downsizing diesel engines to very small displacements is studied. The goal of the article is to determine the minimum displacement a diesel engine can achieve, given the limitations posed by state-of-the-art technology. At the same time, the objective is the maximization of power density with acceptable levels of fuel consumption. While the investigations focused on the thermodynamic behavior of downsizing, structural aspects were also considered.\u0000 On the basis of a literature study, the article illustrates the benchmarking of existing small gasoline and diesel engines for different applications. Thereafter, a matrix of engine configurations, which were relevant to the investigations, was generated. This included, among others, various bore / stroke combinations, compression ratios, piston and nozzle geometries, as well as valve diameters. Further, the influence of injection pressure, swirl and air-fuel ratio were included in the study. With the aid of the 1D simulation software GT-Power and the 3D CFD code Kiva-3V, a detailed thermodynamic analysis was performed on the chosen variants.\u0000 In the results detailed in this article, a promising downsizing potential for a cylinder displacement well below 200cm3/cylinder has been established. Further, best-in-class power densities at acceptable fuel consumption levels could be achieved. This opens up the possibility for the application of such small diesel engines in a new range of applications. The challenges on the thermodynamic and structural fronts, which need to be met in order to achieve targets, are also highlighted.","PeriodicalId":448421,"journal":{"name":"Volume 2: Emissions Control Systems; Instrumentation, Controls, and Hybrids; Numerical Simulation; Engine Design and Mechanical Development","volume":"70 10","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132237147","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}