SAE International journal of advances and current practices in mobility最新文献

{"title":"Spectroscopy Based Tool for Temperature Evaluation during the Spark Discharge","authors":"S. Merola, A. Irimescu, B. Vaglieco, S. D. Iorio, P. Sementa","doi":"10.4271/2019-32-0502","DOIUrl":"https://doi.org/10.4271/2019-32-0502","url":null,"abstract":"In this work, a new tool is proposed and tested to investigate the early phase of spark ignition (SI) processes. The diagnostic tool is based on Spark-Induced Breakdown Spectroscopy (SIBS), a consolidated technique in which the plasma formed by spark generation between two electrodes is used as the excitation source for optical emission spectroscopy (OES).The spark discharge of a commercial ignition system was analyzed through OES to correlate the characteristic evolution of the discharge with the formation of reactive species inside the activated volume. Specifically, an open-source spectrum simulation program (Lifbase) together with the NIST database was used for defining relations between the ultraviolet emission bands of nitrogen first negative system (FNS_N2) in the glow phase for different plasma temperature and pressure values.Besides plasma density and ion energy, electron and gas temperatures are important parameters that govern the reaction rate of active species generation through dissociation, excitation, and ionization processes and thus influence the chemistry of the spark discharge. It is well known that the electrical discharge occurring between the spark plug electrodes can be divided into three phases (breakdown, arc and glow discharge), characterized by different time scales. The breakdown occurrence causes the gas molecules in the ignition area to break into atoms and ions. Molecular recombination starts after some hundreds nanoseconds from breakdown, thus leading to significantly different spectral emissions. Consequently, if measurements are triggered after the time at which breakdown occurs, molecule and molecular radical bands will be dominating in the spectral emission instead of the atomic lines.The proposed methodology takes advantage of the peculiarity of N2 molecules to exchange rotational and translational energy with heavy particles faster than with electrons. For this reason it is possible that rotational distributions quickly achieve thermodynamic equilibrium with the bulk gas. Therefore, a convenient way to determine the gas temperature is through the measurement of the roto-vibrational band spectrum of nitrogen.The validation of the developed tool was performed by considering the emission of excited species detected in ambient conditions. Successively, the methodology was applied in an optically accessible combustion chamber of a spark ignition research engine under motored and fired conditions, and further validated by temperature evaluations based on CN and OH emission bands ratio. The proposed tool allowed obtaining deeper insight into the complex physical and chemical phenomena underlying the ignition event.","PeriodicalId":87358,"journal":{"name":"SAE International journal of advances and current practices in mobility","volume":"28 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84651454","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 Sub-Chamber Configuration on Heat Release Rate in a Constant Volume Chamber simulating Lean-burn Natural Gas Engines","authors":"Y. Nada, Y. Kidoguchi, Yuto Yamashita, R. Furukawa, Ryu Kaya, Hideaki Nakano, S. Kobayashi","doi":"10.4271/2019-32-0551","DOIUrl":"https://doi.org/10.4271/2019-32-0551","url":null,"abstract":"Sub-chamber is a useful device with regard to sustaining stable operation of compressed natural gas (CNG) engines under lean burn conditions. In our previous studies, we applied a sub-chamber injection system to CNG engines, in which a single injector and a spark plug are mounted in a small sub-chamber. The aim of this study is to investigate the effect of the sub-chamber configuration on heat release in the main combustion chamber. 11 types of sub-chamber with different nozzle number, nozzle diameter, and sub-chamber volume were examined under a condition that pressure is 2.3 MPa, and global equivalence ratio is 0.6. When the sub-chamber with smaller nozzles are used, the penetration velocity of burned gas jet increases. In addition, the velocity also increases with an increasing sub-chamber volume. The high-speed penetration of burned gas jet shortens the period of initial flame development. This is because the high-temperature burned gas quickly reaches to side wall of main chamber, and immediately ignites lean mixtures existing in the main chamber. Consequently, combustion duration time until heat release reaches 90 % is also shortened. On the other hand, the velocity difference between the jets from sub-chambers with different nozzle numbers is small. To predict the penetration velocity, we proposed an empirical formula based on the volume, nozzle diameter and nozzle number of sub-chamber. The jet intensity evaluated from the formula shows correlations with duration times of combustion periods as well as penetration velocities of burned gas jets.","PeriodicalId":87358,"journal":{"name":"SAE International journal of advances and current practices in mobility","volume":"6 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77042445","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":"Modeling Subjective Evaluation of Instantaneous Sound Qualities of Motorcycle Exhaust Sound Applying a Highly Efficient Experimental Design","authors":"Kazuhiko Tanaka, S. Nishina, Haruomi Sugita, Takeo Kato, M. Sekita","doi":"10.4271/2019-32-0594","DOIUrl":"https://doi.org/10.4271/2019-32-0594","url":null,"abstract":"<div class=\"section abstract\"><div class=\"htmlview paragraph\">Exhaust sound quality is one of the most important factors for attractive motorcycles. It is desirable to quantitatively and objectively examine the exhaust sound quality during the development process.</div><div class=\"htmlview paragraph\">In our previous study, we developed evaluation models that could be applied to various exhaust sounds. However, due to the limitation of the model, it could not be applied to varying conditions, such as from acceleration to steady driving and then to deceleration. In this study, we developed more practical evaluation models that can be applied to various driving conditions.</div><div class=\"htmlview paragraph\">To cover a wide variety of sounds under different driving conditions, we prepared more than 300 sound stimuli and collected subjective evaluation data on those sounds. As the evaluation method, we used a pairwise comparison method to make decision making easy for the participants. However, if the pairwise comparison was simply performed for such sample size, the experiment cannot be done in a realistic experimental scale because the number of evaluation pairs gets very large. To solve this issue, we allocated evaluating pairs among multiple participants and used the Bradley-Terry model for estimation of the subjective quality rate. With these methods, the number of evaluations per participant was reduced to 1/300 of that required with the naive method.</div><div class=\"htmlview paragraph\">We constructed the models based on a multiple regression analysis on the subjective evaluation data with waveform feature values as independent variables. We confirmed that these models accurately predicted the motorcycle developers' subjective impression of the exhaust sound of actual vehicles under a wide range of driving conditions.</div></div>","PeriodicalId":87358,"journal":{"name":"SAE International journal of advances and current practices in mobility","volume":"13 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74278897","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":"High Speed Orbital Drilling Optimization and Fatigue Life Enhancement by Orbital Roller Burnishing for Aluminum Alloy","authors":"Landry Arnaud Kamgaing Souop, Y. Landon, J. Senatore, A. Daidié, M. Ritou","doi":"10.4271/2019-01-1861","DOIUrl":"https://doi.org/10.4271/2019-01-1861","url":null,"abstract":"","PeriodicalId":87358,"journal":{"name":"SAE International journal of advances and current practices in mobility","volume":"12 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84814914","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":"Fine Tuning the SST k − ω Turbulence Model Closure Coefficients for Improved NASCAR Cup Racecar Aerodynamic Predictions","authors":"Chen Fu, C. P. Bounds, M. Uddin, Christian Selent","doi":"10.4271/2019-01-0641","DOIUrl":"https://doi.org/10.4271/2019-01-0641","url":null,"abstract":"","PeriodicalId":87358,"journal":{"name":"SAE International journal of advances and current practices in mobility","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87593922","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":"Simulation and Measurement of Transient Fluid Phenomena within Diesel Injection","authors":"M. Gold, R. Pearson, J. Turner, Daniel Sykes, V. Stetsyuk, G. de Sercey, C. Crua, Mithun Murali-Girija, F. Koukouvinis, M. Gavaises","doi":"10.4271/2019-01-0066","DOIUrl":"https://doi.org/10.4271/2019-01-0066","url":null,"abstract":"Rail pressures of modern diesel fuel injection systems have increased significantly over recent years, greatly improving atomisation of the main fuel injection event and air utilisation of the combustion process. Continued improvement in controlling the process of introducing fuel into the cylinder has led to focussing on fluid phenomena related to transient response. High-speed microscopy has been employed to visualise the detailed fluid dynamics around the near nozzle region of an automotive diesel fuel injector, during the opening, closing and post injection events. Complementary computational fluid dynamic (CFD) simulations have been undertaken to elucidate the interaction of the liquid and gas phases during these highly transient events, including an assessment of close-coupled injections. Microscopic imaging shows the development of a plug flow in the initial stages of injection, with rapid transition into a primary breakup regime, transitioning to a finely atomised spray and subsequent vaporisation of the fuel. During closuring of the injector the spray collapses, with evidence of swirling breakup structures together with unstable ligaments of fuel breaking into large slow-moving droplets. This leads to sub-optimal combustion in the developing flame fronts established by the earlier, more fully-developed spray. The simulation results predict these observed phenomena, including injector surface wetting as a result of large slow-moving droplets and post-injection discharge of liquid fuel. This work suggests that post-injection discharges of fuel play a part in the mechanism of the initial formation, and subsequent accumulation of deposits on the exterior surface of the injector. For multiple injections, opening events are influenced by the dynamics of the previous injection closure; these phenomena have been investigated within the simulations.","PeriodicalId":87358,"journal":{"name":"SAE International journal of advances and current practices in mobility","volume":"28 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79018480","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":"Benchmarking a 2018 Toyota Camry 2.5-liter Atkinson Cycle Engine with Cooled-EGR.","authors":"John Kargul, Mark Stuhldreher, Daniel Barba, Charles Schenk, Stanislav Bohac, Joseph McDonald, Paul Dekraker","doi":"10.4271/2019-01-0249","DOIUrl":"10.4271/2019-01-0249","url":null,"abstract":"<p><p>As part of the U.S. Environmental Protection Agency's (EPA's) continuing assessment of advanced light-duty automotive technologies in support of regulatory and compliance programs, a 2018 Toyota Camry A25A-FKS 4-cylinder, 2.5-liter, naturally aspirated, Atkinson Cycle engine with cooled exhaust gas recirculation (cEGR) was benchmarked. The engine was tested on an engine dynamometer with and without its 8-speed automatic transmission, and with the engine wiring harness tethered to a complete vehicle parked outside of the test cell. Engine and transmission torque, fuel flow, key engine temperatures and pressures, onboard diagnostics (OBD) data, and Controller Area Network (CAN) bus data were recorded. This paper documents the test results under idle, low, medium, and high load engine operation. Motoring torque, wide open throttle (WOT) torque and fuel consumption are measured during transient operation using both EPA Tier 2 and Tier 3 test fuels. The design and performance of this 2018 2.5-liter engine is described and compared to Toyota's published data and to EPA's previous projections of the efficiency of an Atkinson Cycle engine with cEGR. The Brake Thermal Efficiency (BTE) map for the Toyota A25A-FKS engine shows a peak efficiency near 40 percent, which is the highest value of any publicly available map for a non-hybrid production gasoline internal combustion (IC) engine designed to run on 91 RON fuel. Further improvement is possible by application of fixed discrete or full continuous cylinder deactivation, both of which are currently in production on other engines.</p>","PeriodicalId":87358,"journal":{"name":"SAE International journal of advances and current practices in mobility","volume":"1 2","pages":"601-638"},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7425626/pdf/nihms-1606144.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38269378","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of Drag Reduction Technologies for Light-Duty Vehicles Using Surface, Wake and Underbody Pressure Measurements to Complement Aerodynamic Drag Measurements.","authors":"Fenella de Souza, Arash Raeesi, Marc Belzile, Cheryl Caffrey, Andreas Schmitt","doi":"10.4271/2019-01-0644","DOIUrl":"10.4271/2019-01-0644","url":null,"abstract":"<p><p>Amulti-year, multi-vehicle study was conducted to quantify the aerodynamic drag changes associated with drag reduction technologies for light-duty vehicles. Various technologies were evaluated through fullscale testing in a large low-blockage closed-circuit wind tunnel equipped with a rolling road, wheel rollers, boundary-layer suction and a system to generate road-representative turbulent winds. The technologies investigated include active grille shutters, production and custom underbody treatments, air dams, wheel curtains, ride height control, side mirror removal and combinations of these. This paper focuses on mean surface-, wake-, and underbody-pressure measurements and their relation to aerodynamic drag. Surface pressures were measured at strategic locations on four sedans and two crossover SUVs. Wake total pressures were mapped using a rake of Pitot probes in two cross-flow planes at up to 0.4 vehicle lengths downstream of the same six vehicles in addition to a minivan and a pick-up truck. A smaller rake was used to map underbody total pressures in one cross-flow plane downstream of the rear axle for three of these vehicles. The results link drag reduction due to various technologies with specific changes in vehicle surface, rear underbody and wake pressures, and provide a database for numerical studies. In particular, the results suggest that existing or idealized prototype technologies such as active grille shutters, sealing the external grille and ride height control reduce drag by redirecting incoming flow from the engine bay or underbody region to smoother surfaces above and around the vehicle. This mechanism can enhance the reduction in wheel drag due to reduced wheel exposure at lowered ride height. Sealing the external grille was found to redirect the flow more efficiently than closing the grille shutters, and resulted in greater drag reduction. Underbody treatments were also found in some cases to redistribute the flow around the vehicle to reduce pressure drag in addition to underbody friction drag. The magnitude and spatial extent of the measured pressure changes due to the various technologies were often consistent with the amount of drag reduction.</p>","PeriodicalId":87358,"journal":{"name":"SAE International journal of advances and current practices in mobility","volume":"1 3","pages":"1233-1250"},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7153308/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"37830626","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}