Criteria

Text:
Affiliation:
Display:

Results

Viewing 1 to 30 of 1131
Technical Paper
2014-10-13
Antonino La Rocca, David MacMillan, Paul Shayler, Michael Murphy, Ian Pegg
Cold idle operation of a modern design light duty diesel engine and the effect of multiple pilot injections on stability were investigated. Magnitude and cycle-to-cycle variation of indicated parameter have been used as key indicators of cold idle performance. The utility of different injection strategies, up to three pilot injections before a main, is investigated. The investigation was initially carried out experimentally at 1000rpm, a speed representative of idle conditions, and at -20ºC. Benefits of mixture preparation were initially explored by a heat release analysis performed for each case. A CFD investigation was then used to visualise the effect of multiple pilots on in-cylinder mixture distribution, with particular emphasis on how the injection patterns affect the mixture distribution in the proximity of the glow plug. Kiva 3v was used to model the combustion system and fuel injections. A 60º mesh was used taking advantage of rotational symmetry. Combustion system and injector arrangements mimic the HPCR diesel engine used in the experimental investigation.
Article
2014-07-23
Ford Motor Co. announced Tuesday that Paul Mascarenas, Chief Technical Officer and Vice President, Research and Advanced Engineering, will retire after 32 years at Ford, effective Oct. 1. Mascarenas, an SAE Fellow, joined Ford in 1982 and served in leadership positions in Germany, the United Kingdom, and the United States in product planning, program management, body engineering, and powertrain.
Article
2014-07-10
Ford Motor Co. announced Thursday the establishment of the Alan Mulally Leadership in Engineering Scholarship. The scholarship fund, a $1 million program that provides financial assistance to outstanding students pursuing degrees in automotive engineering, honors former CEO Alan Mulally.
Article
2014-06-27
Ford Motor Co. debuted this week the only five-row side-curtain airbag in the automotive industry, according to a company release. The airbag, which is featured in the 2015 Transit 15-passenger wagon, is the largest in any Ford vehicle. 
Technical Paper
2013-10-07
André Ricardo Marchezan, Mauro Andreassa
The largest automobile companies have several corporate, regulatory and customer requirements to integrate into engineering of development [1]. These information need to be split in technical team called disciplines as electrical, chassis, powertrain, etc. The advanced engineering team is responsible to conduct this process with general purpose of facilitating the managing and tracking of creation and execution of the total vehicle/system. However, the interrelation, complexity and lack of engineer's know-how of these systems have been creating innumerous issues into development, launch, manufactory and quality. Insufficient dedicated tools, requirement definitions and poor initial programs formulation are some reasons of these issues. It means that the ability applied in advanced engineering principles and analytical techniques in an automotive engineering context have to be improved. The design axiomatic is a powerful theory applied into vehicle system and component level to understand the engineering design process, at both, the conceptual and detail levels and to reduce the gap among information systems.
Technical Paper
2013-04-08
Usman Asad, Prasad Divekar, Ming Zheng, Jimi Tjong
Low temperature combustion (LTC) strategies such as homogeneous charge compression ignition (HCCI), smokeless rich combustion, and reactivity controlled compression ignition (RCCI) provide for cleaner combustion with ultra-low NOx and soot emissions from compression-ignition engines. However, these strategies vary significantly in their implementation requirements, combustion characteristics, operability limits as well as sensitivity to boundary conditions such as exhaust gas recirculation (EGR) and intake temperature. In this work, a detailed analysis of the aforementioned LTC strategies has been carried out on a high-compression ratio, single-cylinder diesel engine. The effects of intake boost, EGR quantity/temperature, engine speed, injection scheduling and injection pressure on the operability limits have been empirically determined and correlated with the combustion stability and performance metrics. For dual-fuel combustion of diesel-ethanol (RCCI), the pilot-to-main fuelling ratio and pilot timing/quantity variations have been investigated to identify high-efficiency or high-load operation.
Technical Paper
2013-04-08
Javier Castellano, Anita Chaudhari, Jim Bromham
The regeneration process of a Diesel Particulate Filter (DPF) consists of an increase in the engine exhaust gas temperature by using post injections and/or exhaust fuel injection during a period of time in order to burn previously trapped soot. The DPF regeneration is usually performed during a real drive cycle, with continuously changing driving conditions. The quantity of post injection/exhaust fuel to use for regeneration is calculated using a combination of an open loop term based on engine speed, load and exhaust gas flow and a closed loop term based on an exhaust gas temperature target and the feedback from a number of sensors. Due to the nature of the system and the slow response of the closed loop term for correcting large deviations, the authority of the fuel calculation is strongly biased to the open loop. However, the open loop fuel calculation might not be accurate enough to provide adequate temperature tracking due to several disturbances in the system. This paper discusses a novel methodology for temperature control of the DPF during regeneration.
Technical Paper
2013-04-08
Federico Perini, Adam Dempsey, Rolf Reitz, Dipankar Sahoo, Benjamin Petersen, Paul Miles
In a recent study, quantitative measurements were presented of in-cylinder spatial distributions of mixture equivalence ratio in a single-cylinder light-duty optical diesel engine, operated with a non-reactive mixture at conditions similar to an early injection low-temperature combustion mode. In the experiments a planar laser-induced fluorescence (PLIF) methodology was used to obtain local mixture equivalence ratio values based on a diesel fuel surrogate (75% n-heptane, 25% iso-octane), with a small fraction of toluene as fluorescing tracer (0.5% by mass). Significant changes in the mixture's structure and composition at the walls were observed due to increased charge motion at high swirl and injection pressure levels. This suggested a non-negligible impact on wall heat transfer and, ultimately, on efficiency and engine-out emissions. In this work, the extensive and quantitative local information provided by the PLIF experiments was used as the reference for assessing the accuracy of the CFD modeling of the engine.
Technical Paper
2013-04-08
Gregory Michael Pietron, Yuji Fujii, Joseph Kucharski, Diana Yanakiev, Nimrod Kapas, Steve Hermann, Ramana Hogirala, Thomas L. Greene
Progress in the design and application of the magneto-elastic torque sensor to automotive drivetrain systems has taken the technology from the concept level to the point where it is considered production feasible. The latest generation of the sensors shows promising results regarding both the capabilities and applications to powertrain controls. Sensor designs, electronics and packaging layout are maturing. Well-defined component specifications and requirements are becoming available. The sensor utilities for real-time shift analysis and friction element control are established through vehicle-level investigation to demonstrate the production feasibility of the technology for transmission torque sensing.
Technical Paper
2013-04-08
Harold Sun, David Hanna, Paul Niessen, Brien Fulton, Liangjun Hu, Eric Curtis, Jianwen Yi
For diesel engines to meet current and future emissions levels, the amount of EGR required to reach these levels has increased dramatically. This increased EGR has posed big challenges for conventional turbocharger technology to meet the higher emissions requirements while maintaining or improving other vehicle attributes, to the extent that some OEMs resort to multiple turbocharger configurations. These configurations can include parallel, series sequential, or parallel - series turbocharger systems, which would inevitably run into other issues, such as cost, packaging, and thermal loss, etc. This study, as part of a U.S. Department of Energy (USDoE) sponsored research program, is focused on the experimental evaluation of the emission and performance of a modern diesel engine with an advanced single stage turbocharger. A production IHI (Ishikawajima Harima Heavy Industries) turbocharger was selected as the base architecture for the turbocharger design with optimizations focused on compressor impeller and turbine wheel designs.
Technical Paper
2013-04-08
Nancy C. Evans, Michael J. Leigh
In January 2011, the National Highway Traffic Safety Administration (NHTSA) published a final rule establishing Federal Motor Vehicle Safety Standard (FMVSS) 226 Ejection Mitigation, with the intent of reducing the occurrence of complete and partial ejections of vehicle occupants during crashes, especially rollover events. FMVSS 226 requires component-level tests to be conducted on ejection mitigation countermeasures (e.g., rollover-activated side curtain airbags). A guided, linear impactor is used to propel a headform into a rollover-activated countermeasure at up to four locations for each side daylight opening in the vehicle, for up to three seating rows. The impact tests are conducted at two energy levels (speeds) and associated impact times: 278 J (20 km/h) at 1.5 s after curtain activation and 178 J (16 km/h) at 6 s. The FMVSSS 226 compliance criterion is that the headform cannot travel more than 100 mm past the inside surface of the side window plane. FMVSSS 226 is scheduled to begin phasing-in on September 1, 2013.
Technical Paper
2013-04-08
Hosuk H. Jung, Thomas G. Leone, Michael H. Shelby, James E. Anderson, Travis Collings
Engine dynamometer testing was performed comparing E10, E20, and E30 splash-blended fuels in a Ford 3.5L EcoBoost direct injection (DI) turbocharged engine. The engine was tested with compression ratios (CRs) of 10.0:1 (current production) and 11.9:1. In this engine, E20 (96 RON) fuel at 11.9:1 CR gave very similar knock performance to E10 (91 RON) fuel at 10:1 CR. Similarly, E30 (101 RON) fuel at 11.9:1 CR resulted in knock-limited performance equivalent to E20 at 10:1 CR, indicating that E30 could have been run at even higher CR with acceptable knock behavior. The data was used in a vehicle simulation of a 3.5L EcoBoost pickup truck, which showed that the E20 (96 RON) fuel at 11.9:1 CR offers 5% improvement in U.S. EPA Metro-Highway (M/H) and US06 Highway cycle tank-to-wheels CO₂ emissions over the E10 fuel, with comparable volumetric fuel economy (miles per gallon) and range before refueling. The results also indicated that the E30 (101 RON) fuel at 11.9:1 CR provides improvements in CO₂ emissions of 5% on the EPA M/H cycle and 7.5% on the US06 Highway cycle, while volumetric fuel economy was 3% lower on the M/H cycle and approximately equal on the US06 Highway cycle, compared to the baseline E10 fuel at 10:1 CR.
Technical Paper
2013-04-08
Zhen Jiang, Wei Chen, Yan Fu, Ren-Jye Yang
Reliability-based design optimization (RBDO) has been widely used to obtain a reliable design via an existing CAE model considering the variations of input variables. However, most RBDO approaches do not consider the CAE model bias and uncertainty, which may largely affect the reliability assessment of the final design and result in risky design decisions. In this paper, the Gaussian Process Modeling (GPM) approach is applied to statistically correct the model discrepancy which is represented as a bias function, and to quantify model uncertainty based on collected data from either real tests or high-fidelity CAE simulations. After the corrected model is validated by extra sets of test data, it is integrated into the RBDO formulation to obtain a reliable solution that meets the overall reliability targets while considering both model and parameter uncertainties. The proposed technique is demonstrated through a vehicle design problem aiming at minimizing the vehicle weight through gauge optimization while satisfying reliability constraints.
Technical Paper
2013-04-08
Zohir Benrabah, Hicham Mir, Yi Zhang
Blow moulding is one of the most important polymer processing methods for producing complex thermoplastic automotive parts. Contrary to injection molding, little attention has focused on process control and simulation of blow molding processes. Yet, there are still several problems that affect the overall success of forming these parts. Among them are thermally induced stresses, relevant shrinkage and part warpage deformations caused by inappropriate mold design and/or processing conditions. Tolerance issues are critical in automotive applications and therefore part deformation due to solidification needs to be controlled and optimized accordingly. The accurate prediction tool of part deformation due to solidification, under different cooling conditions in automotive formed parts, is important and highly suited for part designers to help achieve an efficient production. This paper describes in detail the three dimensional membrane element in large displacement formulation with an integration and implementation of the KBKZ constitutive equation to model the blowing phase of forming processes.
Technical Paper
2013-04-08
Nia R. Harrison, Andrey Ilinich, Peter A. Friedman, Jugraj Singh, Ravi Verma
Traditional warm forming of aluminum refers to sheet forming in the temperature range of 200°C to 350°C using heated, matched die sets similar to conventional stamping. While the benefits of this process can include design freedom, improved dimensional capability and potentially reduced cycle times, the process is complex and requires expensive, heated dies. The objective of this work was to develop a warm forming process that both retains the benefits of traditional warm forming while allowing for the use of lower-cost tooling. Enhanced formability characteristics of aluminum sheet have been observed when there is a prescribed temperature difference between the die and the sheet; often referred to as a non-isothermal condition. This work, which was supported by the USCAR-AMD initiative, demonstrated the benefits of the non-isothermal warm forming approach on a full-scale door inner panel. Finite element analysis was used to guide the design of the die face and blank shape. The forming cell developed for the automated production trials included demonstrations of pre-heating, automation, and formability and established process repeatability, cycle time, and the formability window.
Technical Paper
2013-04-08
Robert A. Stein, James E. Anderson, Timothy J. Wallington
This paper provides an overview of the effects of blending ethanol with gasoline for use in spark ignition engines. The overview is written from the perspective of considering a future ethanol-gasoline blend for use in vehicles that have been designed to accommodate such a fuel. Therefore discussion of the effects of ethanol-gasoline blends on older legacy vehicles is not included. As background, highlights of future emissions regulations are discussed. The effects on fuel properties of blending ethanol and gasoline are described. The substantial increase in knock resistance and full load performance associated with the addition of ethanol to gasoline is illustrated with example data. Aspects of fuel efficiency enabled by increased ethanol content are reviewed, including downsizing and downspeeding opportunities, increased compression ratio, fundamental effects associated with ethanol combustion, and reduced enrichment requirement at high speed/high load conditions. The effects of ethanol content on emissions are also reviewed, including NMOG/CO/NOX, particulate matter, toxic compounds, and off-cycle and evaporative emissions.
Technical Paper
2013-04-08
Ioan Felician Campean, Ed Henshall, Brian Rutter
Automotive Product Development organisations are challenged with ever increasing levels of systems complexity driven by the introduction of new technologies to address environmental concerns and enhance customer satisfaction within a highly competitive and cost conscious market. The technical difficulty associated with the engineering of complex automotive systems is compounded by the increase in sophistication of the control systems needed to manage the integration of technology packages. Most automotive systems have an electro-mechanical structure with control and software features embedded within the system. The conventional methods for design analysis and synthesis are engineering discipline focused (mechanical, electrical, electronic, control, software). Multi-disciplinary systems engineering design requires a more coherent approach to the concurrent development of systems and their integration on a functional basis, supporting the flawless delivery of customer required functions in a robust and reliable manner.
Technical Paper
2012-09-17
Adrian Menendez
Vehicle testing on public roads is used by the automotive community in different locations to evaluate the noise characteristics of brake systems under typical customer usage conditions. These tests are generally carried out on different locations and show results with questionable compatibility as has been concluded on several investigations over the last years [1]. Global projects on the other hand mandate to have tests that can represent vehicle usage in several types of environments in order to have reliable indicators of performance on different conditions. This paper suggests a method to characterize roads on different sites and modify the route to match a specific target.
Technical Paper
2012-09-10
Eric M. Kurtz, Douglas Kuhel, James E. Anderson, Sherry A. Mueller
Two oxygenated fuels were evaluated on a single-cylinder diesel engine and compared to three hydrocarbon diesel fuels. The oxygenated fuels included canola biodiesel (canola methyl esters, CME) and CME blended with dibutyl succinate (DBS), both of which are or have the potential to be bio-derived. DBS was added to improve the cold flow properties, but also reduced the cetane number and net heating value of the resulting blend. A 60-40 blend of the two (60% vol CME and 40% vol DBS) provided desirable cold flow benefits while staying above the U.S. minimum cetane number requirement. Contrary to prior vehicle test results and numerous literature reports, single-cylinder engine testing of both CME and the 60-40 blend showed no statistically discernable change in NOx emissions relative to diesel fuel, but only when constant intake oxygen was maintained. The increased NOx emissions typically reported for oxygenated fuels are believed to be largely due to two factors: 1) the method used to control Exhaust Gas Recirculation (EGR), which is typically based on air mass or EGR rate rather than intake oxygen concentration, and 2) the shift in calibration set points (e.g., EGR, boost pressure, etc.) that result from the increased pedal demand needed to achieve the same torque with oxygenated fuels, due to their lower energy content.
Video
2012-05-29
Plugin Hybrid Electric Vehicles (PHEV) have a large battery which can be used for electric only powertrain operation. The control system in a PHEV must decide how to spend the energy stored in the battery. In this paper, we will present a prototype implementation of a PHEV control system which saves energy for electric operation in pre-defined geographic areas, so called Green Zones. The approach determines where the driver will be going and then compares the route to a database of predefined Green Zones. The control system then reserves enough energy to be able to drive the Green Zone sections in electric only mode. Finally, the powertrain operation is modified once the vehicle enters the Green Zone to ensure engine operation is limited. Data will be presented from a prototype implementation in a Ford Escape PHEV Presenter Johannes Kristinsson
Technical Paper
2012-04-16
Matthew Thornton, Aaron Brooker, Jonathon Cosgrove, Michael Veenstra, Jose Miguel Pasini
One of the most critical elements in engineering a hydrogen fuel cell vehicle is the design of the on-board hydrogen storage system. Because the current compressed-gas hydrogen storage technology has several key challenges, including cost, volume and capacity, materials-based storage technologies are being evaluated as an alternative approach. These materials-based hydrogen storage technologies include metal hydrides, chemical hydrides, and adsorbent materials, all of which have drawbacks of their own. To optimize the engineering of storage systems based on these materials, it is critical to understand the impacts these systems will have on the overall vehicle system performance and what trade-offs between the hydrogen storage systems and the vehicle systems might exist that allow these alternative storage approaches to be viable. To gain a better understanding of the interactions that exist between various materials-based hydrogen storage systems and the vehicle system as well as the engineering challenges that exist when integrating one of these systems with a vehicle, the National Renewable Energy Laboratory (NREL) developed a vehicle-level model designed to be sensitive to these issues.
Technical Paper
2012-04-16
Johannes Kristinsson, Ryan McGee, Hai Yu, Fazal Syed, Finn Tseng, Dimitar Filev, Anthony Phillips
Plugin Hybrid Electric Vehicles (PHEV) have a large battery which can be used for electric only powertrain operation. The control system in a PHEV must decide how to spend the energy stored in the battery. In this paper, we will present a prototype implementation of a PHEV control system which saves energy for electric operation in pre-defined geographic areas, so called Green Zones. The approach determines where the driver will be going and then compares the route to a database of predefined Green Zones. The control system then reserves enough energy to be able to drive the Green Zone sections in electric only mode. Finally, the powertrain operation is modified once the vehicle enters the Green Zone to ensure engine operation is limited. Data will be presented from a prototype implementation in a Ford Escape PHEV
Technical Paper
2012-04-16
Jaclyn E. Johnson, Jeffrey D. Naber, Seong-Young Lee, Eric Kurtz, Nan Robarge, Hai-Wen Ge
Diesel combustion and emissions formation is largely spray and mixing controlled and hence understanding spray parameters, specifically vaporization, is key to determine the impact of fuel injector operation and nozzle design on combustion and emissions. In this study, an eight-hole common rail piezoelectric injector was tested in an optically accessible constant volume combustion vessel at charge gas conditions typical of full load boosted engine operation. Liquid penetration of the eight sprays was determined via processing of images acquired from Mie back scattering under vaporizing conditions by injecting into a charge gas at elevated temperature with 0% oxygen. Conditions investigated included a charge temperature sweep of 800 to 1300 K and injection pressure sweep of 1034 to 2000 bar at a constant charge density of 34.8 kg/m₃. Under these conditions there are noticeable fluctuations in liquid phase penetration once the steady state liquid length has been established, on the order of 10% of the mean liquid length.
Technical Paper
2012-04-16
Bita Ghaffari, Kimberly Lazarz, Daniel Ondrus, Roman Maev, Sergey Titov, Alex Bogachenkov
Adhesive bonding technology is playing an increasingly important role in automotive industry. Ultrasonic evaluation of adhesive joints of metal sheets is a challenging problem in Non-Destructive Testing due to the large acoustic impedance mismatch between metal and adhesive, variability in the thickness of metal and adhesive layers, as well as variability in joint geometry. In this paper, we present the results from a matrix array of small flat ultrasonic transducers for evaluation of adhesively bonded joints in both laboratory and production environments. The reverberating waveforms recorded by the array elements are processed to obtain an informative parameter, whose two-dimensional distribution can be presented as a C-scan. Energy of the reflected waveform, normalized with respect to the energy obtained from an area with no adhesive, is a robust parameter for discriminating "adhesive/no-adhesive" regions. A 52-element, 15-MHz matrix array of square transducers was used in the experiments.
Technical Paper
2012-04-16
Xingfu Chen, Carlos Engler-Pinto, Michael King, Mei Li, Eben Prabhu, Xuming Su
High cycle fatigue material properties are not uniformly distributed on cylinder heads due to the casting process. Virtual Aluminum Casting (VAC) tools have been developed within Ford Motor Company to simulate the effects of the manufacturing process on the mechanical properties of cast components. One of VAC features is the ability to predict the high cycle fatigue strength distribution. Residual stresses also play an important role in cylinder head high cycle fatigue, therefore they are also simulated and used in the head high cycle fatigue analysis. Cylinder head assembly, thermal and operating stresses are simulated with ABAQUS™. The operating stresses are combined with the residual stresses for high cycle fatigue calculations. FEMFAT™ is used for the high cycle fatigue analysis. A user-defined Haigh diagram is built based on the local material properties obtained from the VAC simulation. It is demonstrated that the use of local properties distribution in FEMFAT™ has significantly improved the cylinder head high cycle fatigue simulation results.
Technical Paper
2012-04-16
W.U. Alex Leong, Ismail H. Savci, Andy Hatton, Jonathan Scott
Under the current emissions legislation, most of the diesel-powered vehicles have to use Diesel Particulate Filters (DPF) to remove soot particles from the exhaust gas and the accumulated soot particles have to be removed in regular intervals. To initialize the exhaust gas temperature for soot regeneration, diesel fuel is either injected into the combustion chamber in late engine cycle (e.g. post injection) or vaporized and then discharged into the exhaust gas via a dosing device (e.g. fuel vaporizer). Both approaches though require the exothermic catalyst to convert the fuel into thermal energy. For practical reasons, this paper is concentrated on describing how CFD could be used to model the fuel distribution in an aftertreatment system equipped with fuel vaporizer and the exothermic reactions in the catalysts. The authors have already demonstrated in other publications that in order to capture the correct mixing behavior of the exhaust gas and vaporized fuel, one has to use an advanced turbulence model which does not rely on a wall function assumption.
Technical Paper
2012-04-16
James E. Anderson, Thomas G. Leone, Michael H. Shelby, Timothy J. Wallington, Jeffrey J. Bizub, Michael Foster, Michael G. Lynskey, Dusan Polovina
Ethanol has a high octane rating and can be added to gasoline to produce high octane fuel blends. Understanding the octane increase with ethanol blending is of great fundamental and practical importance. Potential issues with fuel flow rate and fuel vaporization have led to questions of the accuracy of octane measurements for ethanol-gasoline blends with moderate to high ethanol content (e.g., E20-E85) using the Cooperative Fuel Research (CFR™) engine. The nonlinearity of octane ratings with volumetric ethanol content makes it difficult to assess the accuracy of such measurements. In the present study, Research Octane Number (RON) and Motor Octane Number (MON) were measured for a matrix of ethanol-gasoline blends spanning a wide range of ethanol content (E0, E10, E20, E30, E50, E75) in a set of gasoline blendstocks spanning a range of RON values (82, 88, 92, and 95). Octane ratings for neat ethanol, denatured ethanol, and hydrous ethanol were also measured. One set of measurements was conducted using a CFR™ engine equipped with manufacturer-supplied enhancements (GE Energy Waukesha XCP-OA™ digital octane panel) for digital knock measurement and precise control of temperatures and fuel flow.
Technical Paper
2012-04-16
Simanta Ghosh, Anindya Deb, Manoj Mahala, Morteza Tanbakuchi, Matthew Makowski
Yaw rate of a vehicle is highly influenced by the lateral forces generated at the tire contact patch to attain the desired lateral acceleration, and/or by external disturbances resulting from factors such as crosswinds, flat tire or, split-μ braking. The presence of the latter and the insufficiency of the former may lead to undesired yaw motion of a vehicle. This paper proposes a steer-by-wire system based on fuzzy logic as yaw-stability controller for a four-wheeled road vehicle with active front steering. The dynamics governing the yaw behavior of the vehicle has been modeled in MATLAB/Simulink. The fuzzy controller receives the yaw rate error of the vehicle and the steering signal given by the driver as inputs and generates an additional steering angle as output which provides the corrective yaw moment. The results of simulations with various drive input signals show that the yaw stability controller using fuzzy logic proposed in the current study has a good performance in situations involving unexpected yaw motion.
Technical Paper
2012-04-16
Robert A. Stein, Dusan Polovina, Kevin Roth, Michael Foster, Michael Lynskey, Todd Whiting, James E. Anderson, Michael H. Shelby, Thomas G. Leone, Steven VanderGriend
Ethanol and other high heat of vaporization (HoV) fuels result in substantial cooling of the fresh charge, especially in direct injection (DI) engines. The effect of charge cooling combined with the inherent high chemical octane of ethanol make it a very knock resistant fuel. Currently, the knock resistance of a fuel is characterized by the Research Octane Number (RON) and the Motor Octane Number (MON). However, the RON and MON tests use carburetion for fuel metering and thus likely do not replicate the effect of charge cooling for DI engines. The operating conditions of the RON and MON tests also do not replicate the very retarded combustion phasing encountered with modern boosted DI engines operating at low-speed high-load. In this study, the knock resistance of a matrix of ethanol-gasoline blends was determined in a state-of-the-art single cylinder engine equipped with three separate fuel systems: upstream, pre-vaporized fuel injection (UFI); port fuel injection (PFI); and DI. Constant inlet temperature was held downstream of the injector for UFI and upstream of the injectors for PFI and DI.
Technical Paper
2012-04-16
Jon Olson, Steven Lambert
This paper summarizes hot surface ignition characteristics of R134a and R1234yf automotive air conditioning fluids on typical under-hood automotive surfaces that possess sufficient heat to ignite flammable or combustible fluids. It further investigates the effect, if any, that these two different fluids may have on the propagation of a fire in two identically equipped vehicles under similar test conditions. This testing, in part, is in response to the United States Environmental Protection Agency's proposal which seeks comments concerning the proposed replacement of the current R134a air conditioning refrigerant with R1234yf. R134a is currently regarded as the global choice for automotive air conditioning systems however the EPA classifies it as an ozone-depleting substance (ODS) and is tasked with proposing and reviewing alternatives that do not contribute to stratospheric ozone depletion. R1234yf refrigerant is classified as a non-ozone-depleting gas by the EPA and has been proposed as an acceptable alternative to R134a through the authority of the Clean Air Act and the Significant New Alternatives Policy (SNAP) program.
Viewing 1 to 30 of 1131

Filter

  • Range:
    to:
  • Year: