OurTechnical Publications




SAE Paper 2012-01-0700: Parametric Analysis of Piston Bowl Geometry and Injection Nozzle Configuration using 3D CFD and DoE

(16.04.2012) In meeting the stringent emission norms with internal engine measures, the design of the piston bowl and the nozzle configuration perform a defining role. Through 3D CFD simulations, this article shall parametrically investigate the influence of piston bowl geometry and nozzle characteristics on the performance of the combustion system. After validation of the 3D simulation model with experimental results, a Design of Experiment (DoE) method shall be applied to analyze a matrix of piston bowls with parametric variations in geometry. Further, the influence of the nozzle cone angle, hydraulic flow rate, number of holes and their combination shall be determined using systematic parameter variations with selected piston bowl designs. The performance of the various hardware configurations would be evaluated based on the exhaust emissions and fuel consumption values. The combustion system under consideration is the Advanced Heavy Duty Combustion System (AHDCS) developed by FEV, which employs a narrow cone angle and a deeper piston bowl. Very high rail pressures and highly cooled Exhaust Gas Recirculation (EGR) strategy shall be used to exploit the full potential of the combustion system. An understanding of the phenomenological behavior of the spray-bowl interaction based on this parametric analysis would lay the groundwork for further optimization of the combustion system.

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SAE Paper 2012-01-0895: Road Map for Addressing Future On-Board-Diagnostic Challenges in Light and Heavy-Duty Diesel Engines

(16.04.2012) The current and future demands on emissions and performance requirements are pushing the envelope with respect to management of complex control software strategies, hardware components and their interactions. This further challenges the implementation of OBD. In this paper, several methods will be presented that can be utilized to achieve a successful and robust diagnostic system implementation. This paper will address diagnostic fault handling based on symptoms, statistical methodologies for filtering out noise, and implementation of reference models for diagnostics. It will also discuss redefining the goal of OBD implementation on modern control systems that have multiple I/O as well as coupled and decoupled configurations.

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SAE Paper 2012-01-0928: Virtual Testing and Simulation Environment for Engine and Aftertreatment Calibration and Development

(16.04.2012) The growing complexity of powertrain control strategies, software, and hardware is proving to be a significant challenge to the engineering community with regard to managing effective optimization to meet the desired performance. With an increased emphasis on shorter development time and the use of additional sensors andactuators becoming common, the increased dependence on physical models and use of complex interdependent control systems demands a thorough system understanding. This also encourages the use of process improvement tools to assist in an effective engineering process. In this paper, a tool is discussed in its second phase of development. The Micro-HiL system™ will be discussed over a scope that focuses on the interests of the calibration and development community.

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Transmission Development Process

(18.07.2011) One of FEV's fields of activities is the transmission engineering service and the complete design & development process. With extensive know-how of development, quality and cost oriented engineering; FEV presents itself as the ideal partner for a successful close cooperation project.

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Cranktrain Design Optimized for Reducing Weight and Friction Supported by Coupled CAE Tools

(06.04.2009) The OEMs are currently being faced with a variety of contradictions in terms of market demands and governmental regulations, which force them to develop concepts that assure high fuel economy, low exhaust emissions and high specific power. Because mechanical losses can account for up to 10% of the fuel energy used, the key to achieving these specific customer/government demands is to enhance the mechanical performance of the engine by decreasing friction and through the development of lightweight engine parts

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Designing Exhaust Manifolds Using Integral Engineering Solutions

(06.04.2009) Exhaust manifold cracks from Thermomechanical Fatigue (TMF) are often seen on highly loaded engines, due to increasing marketplace demands for performance and emissions. A constant search for higher strength materials is needed, due to maximum gas temperatures that in some instances are already above 1000°C. The use of virtual prototypes for creating a development strategy for testing will reduce expense and time as opposed to using physical prototypes.

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Turning Innovation into Mass Production

(04.09.2009) The development of next generation of internal combustion engines has to compromise the increased demands on performance, weight and reliability considering lower product costs. This results in an all-embracing development process from concept to SOP.

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Developing a Virtual Engine and Transmission Combined with a Modern Geartrain

(01.09.2009) Simulation Process Simulation tools are an integral part of a modern research and development program to determine the dynamic system response and the component stresses. These investigations are based on the utilization of the latest multi-body and finite-element techniques.

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Diesel Systems

Impact of Fuel Properties on the Performance of a Direct Injection Diesel Engine under Part Homogeneous Operating Conditions

(12.04.2011) Tightening of emission norms necessitate intensified research in the field of emissions reduction. Fuel research opens up a vast area of potential improvement, since combustion behavior and the nature of the combustion products can be heavily influenced by fuel composition. In this paper, the effects of fuel properties on combustion and emissions shall be discussed, based on the study of standard diesel fuel, two types of diesel-like fuels and a kerosene fuel. Investigations were conducted on a single cylinder heavy duty direct-injected diesel engine operating under part-homogeneous combustion in the part-load operating range. For this purpose, a statistical design of experiments method (DOE) was utilized in order to evaluate the influence of each fuel property and, thus, develop a model for all selected fuels.

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Relationship between fuel properties and sensitivity analysis of non-aromatic and aromatic fuels used in a single cylinder heavy duty diesel engine

(12.04.2011) The necessity to reduce the emissions, pollutants as well as CO2 from ICE’s leads since many years to the generalization of diesel engines, whose one of the advantage compared to spark ignition engines is the lowest level of these greenhouse gases, which contributes to the climatic effects. However, diesel engines produce higher NOx and particulate matter (PM) emissions that leads to expensive, difficult and complex exhaust gas after treatment systems. That is the driver for continuous research, heading towards alternative combustion modes, which allow a drastic reduction of engine-out emissions at favorable fuel efficiency.

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SAE Paper 2011-01-0703: Development and Calibration of On-Board-Diagnostic Strategies Using a Micro-HiL™ Approach

(12.04.2011) Beginning in 2010, implementation of on-board diagnostics (OBD) is mandatory for all the heavy-duty engine applications in the United States. The task of developing OBD strategies and calibrating them is a challenging one. The process involves a strong interdependency on base engine emissions, controls and regulations. On top of that the strategies developed as a result of the regulatory requirements need to go through a stringent and time-intensive process of software implementation and integration. The goal of this paper is to provide a concise overview of a process utilized to help the development, testing and calibration of the OBD strategies on a 2010 model year heavy-duty diesel engine. The paper will focus on the setup of hardware-software-in-the-loop in detail by describing the components involved in the setup and their functionalities. The main components of the integrated system presented in this paper include the following: MATLAB® Simulink® software, an Integrated Calibration and Acquisition System (INCA ® ), an engine control unit (ECU), and a GT-POWER® engine performance model.

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SAE Paper 2011-01-0299: Pre-Turbo Aftertreatment Position for Large Bore Diesel Engines - Compact & Cost-Effective Aftertreatment with a Fuel Consumption Advantage

(12.04.2011) Tier 4 emissions legislation is emerging as a clear pre-cursor for widespread adoption of exhaust aftertreatment in offhighway applications. Large bore engine manufacturers are faced with the significant challenge of packaging a multitude of catalyst technologies in essentially the same design envelope as their pre-Tier 4 manifestations, while contending with the fuel consumption consequences of the increased back pressure, as well as the incremental cost and weight associated with the aftertreatment equipment.

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SAE Paper 2010-01-0335: Potential of Cellulose-Derived Biofuels for Soot Free Diesel Combustion

(12.04.2010) Today’s biofuels require large amounts of energy in the production process for the conversion from biomass into fuels with conventional properties. To reduce the amounts of energy needed, future fuels derived from biomass will have a molecular structure which is more similar to the respective feedstock.

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FEV HD 1-Cylinder Research Engine

(04.09.2009) FEV is offering a single cylinder engine program for basic res

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Indirect Injection Heavy-Duty Diesel Engine Emission Control Concept - Achieving the 2007 Emission Standard

(01.09.2009) All HD engine manufacturers for 2010 will be have to apply NOx aftertreatment in addition to the PM aftertreatment that is introduced with the MY 2007 engines in order to achieve the required emission standards. Direct injected diesel engines from 2007 through 2010 will control NOx through internal engine measures, such as increased EGR levels and retarded injection timing.

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Particulate Matter & NOx Exhaust Aftertreatment

(01.09.2009) Fleet fuel consumption is greatly reduced through the introduction of the HSDI Diesel engine. The reduced fuel consumption is then reflected in a reduction of CO2 emissions. The drop in fuel consumption and CO2 emissions results in a rise in market acceptance, which is also the result of desirable driving performance and greatly improved NVH behavior. The continuously increasing demands on placed on emissions performance also needs to be addressed.

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Utilizing Model-Based Calibration to Advance Powertrain Development

(01.09.2009) Recently, the methods employed to create an efficient design process have been successfully applied. Individuals involved with testing and vehicle application development can benefit from methods that are model-based. Current models that have a variety of detail are able to vastly improve during almost every phase of the development cycle.

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Impacts of Biodiesel Fuel on U.S. Light-Duty Tier 2 Engine and Emission Control Systems - Part 2

(06.04.2009) In the United States, the combination of an increased interest in diesel powered vehicles and government-mandated policies to reduce dependency of foreign oil, has consequently sparked an interest in biodiesel fuel blends to supply fuel for these vehicles.

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Pre-turbo After-treatment System Development using a 1D Modeling Approach

(06.04.2009) The location of a diesel engine’s after-treatment system can dramatically affect engine performance. A numerical study was conducted to verify that impact in relation to engine performance. A part of that investigation included examining the advantages and disadvantages of locating the after-treatment system before or after the turbocharger. The operating conditions that were used to conduct the testing included both steady-state and transient conditions.

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Small Bore DI Diesel Engine Injection Rate Shaping

(06.04.2009) The impacts injection rate shaping on small bore DI diesel engines have not been extensively studied, especially under high part load conditions with high EGR rates. Testing on heavy-duty engines has already proven the benefits of injection rate shaping under high load conditions, both with and without EGR. The purpose of this study is to reveal the impact of rate shaping on a small bore DI diesel engine. The tests for this study were completed at VKA / RWTH Aachen University, using a single cylinder engine.

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DI-Diesel Engine - Injection Nozzle Coking

(06.04.2009) The primary challenges towards developing new diesel engines for passenger cars lie in the strict future emission legislation in combination with the customer’s demands for steadily improving performance. For example, the emission limitations of Tier 2 Bin 5 requires an advanced aftertreatment system and a robust combustion process that minimizes emissions in the process of them being formed.

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HSDI Diesel Engines - Gas Exchange Optimization and the Impact on Reducing Emission

(06.04.2009) All future powertrain developments must consider the primary tasks of achieving the required emission levels and CO2- values, while still providing comfort, good drivability, high reliability and affordable costs. One method for improving fuel economy in passenger vehicles that is beginning to be examined is the incorporation of downsizing.

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Light-Duty Diesel Engine - Impact of Fuel Properties on Emissions and Performance

(06.04.2009) The increased demands placed on the powertrain community to develop propulsion systems with high fuel efficiency has led to advanced technologies for improving the engine’s overall thermal efficiency, while maintaining low emission levels. Additionally, developing fuels that provide improved combustion and reduce the emission footprint have gained importance as well.

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SAE Paper 2005-01-2490. Diesel Engine Cold Start Noise Improvement

(01.08.2006) Today’s powertrain engineering is faced with growing customer expectations regarding noise and vibration (NVH) what requires the use of virtual development methods starting already in early phases of the development process.

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Heavy Duty Engine Design

(03.08.2006) Over the past several years, FEV has gained experience in the design and development of Medium to Heavy Duty Engines for numerous applications.

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Lightweight Diesel Automotive

(04.04.2005) The continued growth in the number of diesel engines being used in European passenger cars is shown in the registration statistics. Those statistics show that their share in new registrations has almost tripled and is currently at more than 40% over the past 12 years.

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Gasoline Systems

SAE Paper 2011-01-0343: Systematic Approach to Analyze and Characterize Pre-Ignition Events in Turbocharged Direct-Injected Gasoline Engines

(12.04.2011) Downsized direct-injected boosted gasoline engines with high specific power and torque output are leading the way to reduce fuel consumption in passenger car vehicles while maintaining the same performance when compared to applications with larger naturally aspirated engines. When targeting high output levels at low engine speeds, undesired combustion events called pre-ignition can occur. These pre-ignition events are typically accompanied by very high cylinder peak pressures which can lead to severe damage if the engine is not designed to withstand these high cylinder pressures. This paper describes a systematic engine dyno testing approach to force the engine into pre-ignition in order to study and characterize these events.

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SAE Paper 2010-01-0169: Multi-Cylinder Airflow & Residual Gas Estimation Tool Applied to a Vehicle Demonstrator

(13.4.2010) Accurate fueling is a key precursor to improved engine fuel economy, and reduced engine out emissions. Asymmetric flow paths to cylinders in certain engines can cause differences in the gas exchange process, which in turn cause imbalances in trapped fresh charge and RGF. Due to the reasons stated, simplified models can result in significant estimation errors for fresh trapped charge and RGF if they are not gas dynamics-based or detailed enough to handle features such as variable valve timing, duration, or lift. In this paper, a new air flow and RGF measurement tool is introduced. The tool is a combination of 1-D gas dynamics modeling and imposed, measured dynamic pressure signals in the intake and exhaust manifolds.

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Specific Durability Testing with FEV Master Program

(12.04.2010) During the past years, there has been an increasing tendency to seriously question and break up old and ingrained structures in combustion engine testing. The reason for this is the continuously increasing number of engine and vehicle variants and a variety of applications resulting from it, which significantly push up development costs and times when carrying out the classical testing patterns.

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Development of a Two-stage Variable Compression Ratio Engine

(06.04.2009) Fuel consumption can be reduced in highly boosted gasoline engines with a Variable Compression Ratio (VCR). The increase in fuel economy is the result of operating an engine with higher compression ratios at low load compared to an engine with fixed compression ratio. The two-stage VCR-system provides a high share of the potential fuel savings in comparison to fully variable system.

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Strategies for Operation of Controlled Auto Ignition Gasoline Engines

(06.04.2009) A tremendous opportunity exists for reducing fuel consumption and emissions in gasoline engines under part load operation, with the use of a Controlled Auto Ignition (CAI) system. The start of controlled auto ignition is achieved by reaching thermal ignition conditions at the end of compression. Chemical kinetics control the combustion process in a CAI system, which is dramatically different from the conventional premixed combustion process. Accordingly, the thermodynamic state determines the CAI combustion process, which can be either controlled by a high amount of residual gas and stratification of air or residual gas and fuel.

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Cyclic Fluctuations of Charge Motion & Mixture Formation in a DISI Engine in Stratified Operation

(06.04.2009) The processes of an internal combustion engine are subject to cyclic fluctuations, which have direct consequence on the operational and emission behavior of the engine. Direct injection gasoline engines have fluctuations that are induced and superimposed by the flow and the injection. In stratified operation they can cause serious operating problems, such as misfiring. Currently, the state of knowledge on the formation and causes of cyclic fluctuations is rather limited, which can be attributed to the complex nature of flow instabilities.

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Boosting the Future - Concept Layout and Design of Advanced Charging Systems

(18.09.2006) One of the key technologies for future Diesel and gasoline engines will be concepts based on advanced boosting systems.

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Roller-Bearings in Combustion Engines –an Effective Way for Fuel Saving

(01.08.2006) The fuel consumption of an internal combustion engine is significantly driven by the engine friction. Main and conrod bearings contribute - beside the piston-liner contact – substantially to friction losses.

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Boosting and Direct Injection - Synergies for Future Gasoline Engines

(04.04.2005) To further reduce the Corporate Average Fuel Economy (CAFE) in order to meet the ACEA (Association des Constructeurs Européens d'Automobiles) target values agreed upon, more intense efforts are required in the areas of engine and drivetrain development by 2008 or 2012. The engines that will lead to that goal will be boosted gasoline engines with a high specific output or torque that will combine driving pleasure and reduced fuel consumption. FEV has thoroughly analyzed this kind of concept and the fundamental synergy effects resulting from the combination of supercharging with direct injection.

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White Paper on a Gasoline Powered PEMFC APU System Control Strategy

(01.03.2004) Fuel cell based Auxiliary Power Units (APU) present an intricate system consisting of different subsystems, components and low-level controllers. A sophisticated supervisory control is needed, particularly in the case of gasoline-fueled systems, to manage the sequential control and to achieve a fault tolerant and fail-safe operation.

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Multidisciplinary Services

Exhaust-Aftertreatment Integrated, DoE-based Calibration

(16.04.2012) For on- and off highway applications in 2012 / 2014 new legislative emissions requirements will be applied for both European (EURO 6 / stage 4) and US (US 2010 / Tier4 final) standards. Specifically the NOX-emission limit will be lowered down to 0.46 g/kWh (net power > 56 kW (EU) /130 kW (US) - 560 kW). While for the previous emissions legislation various ways could be used to stay within the emissions limits (engine internal and aftertreatment measures), DeNOX-aftertreatment systems will be mandatory to reach future limits. In these kinds of applications fuel consumption of the engines is a very decisive selling argument for customers. Total cost of ownership needs to be as low as possible. The trade-off
between fuel consumption and NOX-emissions forces manufacturers to find an optimal solution, especially with regard to increasing fuel prices.

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Glow-plug Ignition of Ethanol Fuels under Diesel Engine Relevant Thermodynamic Conditions

(13.04.2011) The requirement of reducing worldwide CO2 emissions and engine pollutants are demanding an increased use of bio-fuels. Ethanol with its established production technology can contribute to this goal. However, due to its resistive auto-ignition behavior the use of ethanol based fuels is limited to the spark ignited gasoline combustion process. For application to the compression ignited Diesel combustion process advanced ignition systems are required. In general, ethanol offers a significant potential to improve the soot emission behavior of the Diesel engine due to its oxygen content and its enhanced evaporation behavior.

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Development and Calibration of On-Board-Diagnostic Strategies Using a Micro-HiL Approach

(13.04.2011) The demand for shorter development time for the complex control system designs of modern engines requires using sophisticated tools. Many development tools have their predefined cutting-edge features that are designed to aid product design, analysis, and validation/testing. The competition in this area in the present market is very stiff, and there are sophisticated software-hardware integrated systems available to address the key challenges in today’s automotive development world. The essence of this paper is exploring a cost-effective, flexible, and easy-to-handle system that is able to address some of the real-world challenges faced by engine development and calibration engineers on a daily basis. Although some of the features of the system developed in this paper resemble those of a regular full-scale hardware-in-theloop (HiL) system or any such known integrated systems, the software-in-the-loop (SiL) feature and the Micro-HiL system/approach presented in this paper offer some unique features that are of most interest to the engineering community of engine development and calibration.

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Interpretation tools and concepts for the heat management in the drive train of the future

(13.04.2011) Thermal management describes measures that result in the improved engine or vehicle operation in terms of energetics and thermo mechanics. In this context the involvement of the entire power train becomes more important as the interaction between engine, transmission and temperature sensitive battery package (of hybrid vehicles or electric vehicles with range extender) or the utilization of exhaust gas thermal energy play a major role for future power train concepts.

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Plug-in Powertrain Hybrid Concept; Turbocharged, Two-Valve SOHC Three Cylinder Engine

(22.03.2011) Innovative prototype three-cylinder IC engine with e-drive capability featured in January 2011's edition of Engine Technology International.

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Catalyst Aging Method for Future Emissions Standard Requirements

(13.04.2010) The global vehicle emission legislation defines the requirements in reducing emission levels. As the emission limits for new vehicles operating under the mandated drive cycles are being restricted, a greater focus is also placed on emission sources that were not originally covered. The durability of exhaust aftertreatment systems is a major issue in order to assure an overall reduction in vehicle fleet emissions in the future. Therefore, the durability requirements have been increased to higher mileage, such as with 160,000 km for EURO V [1] and
up to 150,000 miles for the SULEV emission standard [2]. Additionally, tighter thresholds for OBD malfunction detection will be applied. In the past only the OBD limits for THC or NMHC emissions were defined; however, the new requirements also include detection of NOx emissions.

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Optimizing Valve Rotational Speed Using Taguchi Techniques

(13.04.2010) As fuel economy regulations increase and customer preference shifts to smaller, higher power density engines it is more important to effectively cool certain areas of the cylinder head and valvetrain. In order to maximize valvetrain life and increase engine performance it is critical to maintain a near uniform valve seat temperature to enable proper sealing. As cylinder head bridges narrow, and the temperature increases, the water jacket may not be sufficient. An alternative method to ensuring equal temperature distribution across the valve is to promote low speed valve rotation. This will not only aid, cooling the valve seat, as well as cooling and cleaning the valves’ seating surface. This paper describes the development and testing of a valve rotation study, utilizing the Taguchi approach in order to determine the most robust design.

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Dedicated GTL vehicle: a calibration optimization study

(13.04.2010) Light duty vehicle development faces two main challenges: the need to reduce regulated emissions to meet the progressively tightening standards as well as the requirement to reduce the CO2 output. The two routes to reduce local emissions are re-designing the engine and adding after-treatment devices. For reduction of CO2
emissions a large number of measures compete with regard to the cost-effectiveness trade-off, ranging from extreme light-weight vehicles to electrification, to the use of bio-fuels.

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FEV - Engine Design Database

(10.09.2009) FEV's benchmarking involves a systematic assessment and characterization of engines and vehicles that allows direct comparisons between similar products.

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Cost Engineering / Cost Studies

(01.09.2009) Independent of targets regarding performance, emissions, fuel consumption and durability, production costs are always an important factor for a successful engine concept.

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Combustion Engine Development Utilizing Design for Six Sigma (DFSS)

(04.04.2005) Currently, the design of the internal combustion engine are highlighted by a rapid development time with increased demands for high levels of quality, NVH, specific power and lower weight, with reduced production costs. In order to achieve these results, implementation of a new and systemic design management system is required from the outset of the concept to Start of Production (SOP).

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A Modern Approach to Face Current and Future Testing Needs as Part of the Entire Development Process for Vehicles and Engines

(06.02.2003) FEV's benchmarking involves a systematic assessment and characterization of engines and vehicles that allows direct comparisons between similar products.

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Noise Vibration Harshness

Evaluating the Degree of Anoyance Caused by Impulsive Noise Types

(11.10.2011) Disturbing impulsive noises occurring in combustion engines have a particularly detrimental effect on the perceived quality of vehicles and are sometimes misinterpreted by customers as defects. A tool for computing objective evaluations of such disturbing noises has been developed at the Institute for Combustion Engines (VKA) at RWTH Aachen University. By using modern methods of signal analysis to break down disturbing noises into individual noise types, even better results can be obtained than when evaluations are carried out by a jury.

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Electric vehicle sound design - Just wishful thinking?

(04.10.2011) The electrification of vehicle propulsion has caused a radical change also in the world of acoustics. Comments from the media range from „silently hums the future“ to „electric car roars with V8 sound“. Decades of experience in designing brand-specific vehicle sound, based on noise and vibration generated by combustion engines, cannot be simply transferred to the upcoming purely electric power trains. Although electric vehicles are almost always considerably quieter, the interior noise is marked by high-frequent noise components which can be subjectively perceived as annoying and unpleasant. Moreover, disturbing noise is no longer masked by combustion engine noise.

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Driveline boom interior noise prediction based on multi body simulation

(04.10.2011) It is important to develop powertrain NVH characteristics with the goal of ultimately influencing/improving the in-vehicle NVH behavior since this is what matters to the end customer. One development tool called dB(VINS) based on a process called Vehicle Interior Noise Simulation (VINS) is used for determining interior vehicle noise based on powertrain level measurements (mount vibration and radiated noise) in combination with standardized vehicle transfer functions.

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NVH of Hybrid Vehicles

(21.10.2010) The technology used in hybrid vehicle concepts is significantly different from conventional vehicle technology with consequences also for the noise and vibration behavior. In conventional vehicles, certain noise phenomena are masked by the engine noise. In situations where the combustion engine is turned off in hybrid vehicle concepts, these noise components can become dominant and annoying. In hybrid concepts, the driving condition is often decoupled from the operation state of the combustion engine, which leads to unusual and unexpected acoustical behavior.

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Method for Simulating the NVH Behavior of Plastic Materials

(21.10.2010) Lightweight construction is one of the key points for the automotive industry to achieve the ambitious targets for fuel consumption. As a consequence, plastic components are increasingly being used in automobile manufacture. This includes engine components which emit a considerable degree of noise, such as valve covers or oil pans. It is therefore necessary for polymer components to be taken into consideration during the NVH development process of internal combustion engines.

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Application of Combustion Sound Level (CSL) Analysis for Powertrain NVH Development and Benchmarking

(13.10.2009) Powertrain noise is a significant factor in determination of the overall vehicle refinement expected by today’s discriminating automotive customer. Development of a powertrain to meet these expectations requires a thorough understanding of the contributing noise sources. Specifically, combustion noise greatly impacts the perception of sound levels and quality. The relevance of combustion noise development has increased with the advent of newer efficiency-driven technologies such as direct injection or homogeneous charge compression ignition.

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Aspects of NVH Integration in Hybrid Vehicles Kiran Govindswamy and Thomas Wellmann

(24.09.2009) NVH refinement is an important aspect of the powertrain development and  vehicle integration process. The depletion of fossil-based fuels and increase in price of gasoline have prompted most vehicle manufacturers to embrace propulsion technologies with varying degrees and types of hybridization. Many different hybrid vehicle systems are either on the market, or under development, even up to all-electric vehicles. Each hybrid vehicle configuration brings unique NVH challenges that result from a variety of sources. This paper begins with an introductory discussion of hybrid propulsion technologies and associated unique vehicle NVH challenges inherent in the operation of such hybrid vehicles.

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Acoustic Challenges of Roller Bearings in Combustion Engines

(24.09.2009) In addition to the efficiency of gas exchange and combustion, fuel consumption is influenced to a large extent by engine friction. The distribution of mechanical losses shows that with one third, the main and con rod bearings have the largest share in engine friction apart from the piston subassembly. When substituting the plain bearing by a roller bearing, a considerable potential for friction improvement can be realized which leads to a significant reduction of CO2. From a given 1,6l 4-cylinder naturally aspirated gasoline plain bearing engine changed to roller bearings a proved 5,4% (NEDC) improvement of the fuel consumption resulted from reduced friction. The challenges resulting from the use of roller bearings in internal combustion engines are related to the disciplines acoustics, durability, and fabrication. For balancing shafts roller bearings have lately been introduced into serial production [1].

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NVH Refinement of Diesel Passenger Vehicles

(01.09.09) Modern vehicle development requires NVH refinement to obtain the proper level of customer satisfaction and acceptance. This document outlines the vehicle NVH development process, citing specific examples from a process for a diesel engine application that was derived from a gasoline engine application.

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Canceling Oil Pan Active Powertrain Noise

(01.09.2009) The powertrain, under urban driving conditions, is one of the major sources for external vehicle noise. The engine’s oil pan is a major contributor to the overall powertrain sound emission, particularly during idling and full load acceleration. The oil pan can also contribute considerably to the radiated sound levels of the powertrain.

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Analysis of Impulsive Powertrain Noise

(01.09.2009) Refining vehicle NVH is a key aspect of the powertrain development process. Powertrain NVH refinement is impacted not only by overall sound levels, but also sound quality. Powertrain sound quality and therefore the level of NVH refinement can be adversely impacted by excessive impulsive noise.

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Turbo Charger Noise* - Development of a Methodology for the Acoustic Turbo Charger Layout (First Report)

(06.10.2008) Turbo charger acoustics shifts more into the focus of development due to the increasing application of turbocharged engines. Here the noise behavior of turbo chargers leads to a conflict between costs and acoustics. A research program was initiated in order to describe the noise behavior of turbochargers. The research project was assigned by Forschungsvereinigung Verbrennungskraftmaschinen e.V. (FVV, Frankfurt). Systematic experimental investigations were performed and a hybrid simulation methodology was developed. Applying this simulation process, a characterization of the acoustical behavior and the implementation of acoustical measures in the early development phases of the turbo charger can be ensured.

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Vehicle Interior Noise Simulation VINS as a production vehicle development tool (First Report)

(06.10.2008) This article describes vehicle development processes with special emphasis on the NVH aspects of the development. A key portion of the NVH development process is the use of an approach called Vehicle Interior Noise Simulation (VINS) to satisfy different needs during the development process. VINS is based on an analytical method which divides the total interior noise into audible noise shares from different paths. VINS also allows for each path to be further broken down into source and transfer function components, so that the vehicle’s NVH behavior can be understood and optimized. VINS establishes a highly effective platform for dedicated assessment of simulation and physical test results, benchmarking, target-setting and countermeasures in the entire development process from concept to production.

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Optimizing Vehicle NVH Characteristics for Driveline Integration

(04.06.2007) The automotive marketplace has seen a steady increase in customer demands for quiet and more comfortable vehicles. A customer’s expectations for NVH refinement often contradicts the constraints for lightweight vehicle designs and the need for a powertrain with increased fuel efficiency

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Vehicle Exterior Noise Simulation

01.08.2006) Currently, the exterior pass-by noise level during acceleration is the only legal limit in vehicle acoustics. In an effort to further reduce noise emissions, a tightening of limit values and/or procedures is to be expected

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Virtual NVH Powertrain Development

(01.08.2006) Today’s powertrain engineering is faced with growing customer expectations regarding noise and vibration (NVH) what requires the use of virtual development methods starting already in early phases of the development process.

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Application of Vehicle Interior Noise Simulation (VINS) for NVH Analysis of a Passenger Car

(01.08.2005) Development of engine and combustion process relates closely with the layouts of the intake and exhaust ports. The coupling of combustion and emission performance with the intensity of turbulence, quality of mixture formation or the distribution of residual gas is mainly determined by the design of the port and cylinder head.

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Reducing Combustion Noise

The design and development of modern internal combustion engines is marked by a reduction in exhaust gas emissions and increase in specific power and torque. Correspondingly, combustion noise excitation and fuel consumption also have to be reduced. These objectives can be achieved through the development of advanced combustion systems, the increased flexibility of fuel injection systems and ECUs.

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Powertrain Mechanics

Crankshaft Offset & it's Impact on Piston & Piston Ring Friction Behavior

(01.09.2009) Increasing fuel economy in modern passenger car engines has become one of the primary development targets, due to swiftly increasing raw oil prices. Initially, vast progress was achieved in the development of the combustion process. Computer Aided Engineering (CAE) has been one of the keys to success; however, further potential is now being investigated.

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The Necessity of Mechanical Testing

(10.09.2009) Computers have become a key component in the engine development process over the last few decades. Computer based tool usage in the design process is steadily increasing and especially concerning the layout of the various subsystems, which are completed through the use of simulation models. Computer-aided engineering plays a vital role where CFD, FEM, and MBS are applied (e.g. in the design of the combustion process as well as with regards to work performed in the area of engine mechanics).

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First Driving Test Results of FEV's 7H-AMT Hybrid Transmission

(30.09.2011) FEV’s 7H-AMT has been developed within the project “Europa-Hybrid: Innovativer PKWHybridantrieb für Europa” funded by the German Federal Ministry of Economics and Technology (BMWi). This project has taken the 7H-AMT to a working prototype inside a demonstrator vehicle based on the Ford Focus ST. The authors would like to thank the BMWi for its kind support of this ambitious research project.

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New Planetary Based Hybrid Automatic Transmission with Electric Torque Converter and on-Demand Actuation

(30.09.2011) Within the scope of work of the "HICEPS" project funded by the European Union, FEV has developed a new hybrid transmission for transverse installation. This transmission is based on the technology of planetary automatic transmissions and realizes seven forward speeds with only three planetary gear sets, three clutches and two brakes. Because of its innovative layout without hydrodynamic torque converter and with on-demand actuation, it achieves significant better efficiency than conventional automatic transmissions. Besides an electro-hydraulic actuation mechanism, also an electro-mechanic one is under development. The advantages and disadvantages are shown in the paper. The electromechanical actuation is discussed in detail and the first component tests are discussed.

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Future Automatic Transmission Requirements

(30.09.2011) So far engine downsizing in passenger cars has been used to increase the vehicle performance and to compensate the vehicle weight increase. In the future the continuing downsizing trend on the engine side will be used to maintain today’s performance level and further reduce the fuel consumption. To maintain launch performance and at the same time exploit the engine potential a (torque) ratio spread of up to 10 and launch ratio of up to 20 will be necessary. The future automatic transmission will be the enabler to exploit the
potential of these extreme downsized vehicles.

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Concept of an Innovative Passenger-Car Hybrid Drive for European Driving Conditions

(24.09.2009) The downsizing of spark ignition engines in conjunction with turbocharging is considered to be a promising method for reducing CO2 emissions. Using this concept, FEV has developed a new, highly efficient drivetrain to demonstrate fuel consumption reduction and drivability in a vehicle based on the Ford Focus ST. The newly designed 1.8L turbocharged gasoline engine incorporates infinitely variable intake and outlet control timing and direct fuel injection utilizing piezo injectors centrally located. In addition, this engine uses a prototype FEV engine control system, with software that was developed and adapted entirely by FEV. The vehicle features a 160 kW engine with a maximum mean effective pressure of 22.4 bar and 34% savings in simulated fuel consumption.

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FEV Parallel Mode Strategy

(24.09.2009) As the automotive industry has to react to the global concern about climate change related to CO2 emissions and also driven by the rapid increase of the crude oil prices, alternatives to reduce the fuel consumption and reduce the emissions are being explored. One alternative is a hybrid power train, combining the internal combustion engine (ICE) with an electric machine (EM). The control of such a system typically realized with a hybrid control unit (HCU). FEV has developed modular software for HCU and TCU controls. One of the main components in this software structure is the State of charge (SOC) management and torque distribution of a parallel hybrid driveline. This paper describes FEV´s parallel hybrid software as used in various finished and ongoing hybrid development programs.

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FEV’s new parallel hybrid transmission with single dry clutch and electric torque support

(24.09.2009) The following article will give an overview of FEV’s new 7H-AMT (7-speed hybrid AMT), which is being developed within the project “Europa-Hybrid: Innovativer PKW-Hybridantrieb für Europa” funded by the German Federal Ministry of Economics and Technology (BMWi). This project is going to take the 7H-AMT and other hybrid system components from concept to working prototypes inside a demonstrator vehicle based on the Ford Focus ST. The authors would like to thank the BMWi for its kind support of this ambitious research project.

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Efficient Transmission Application by Using Modern Offline Tools

(15.10.2009) This paper uses the application of the automatic gearbox of BMW’s Mini Cooper as an example to give an overview over the efficient tools and calibration processes of FEV Motorentechnik. Focus will be the description of driving strategy calibration, the objective analysis and optimization of shift quality and the requirement based management of calibration parameters.

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The Impact Act of Nonlinear Steering Systems On Objective and Subjective Steering Evaluation

(22.10.2010) Traditionally, vehicle steering systems had a linear relation between steering wheel rotation and road wheel angle. Nonlinear steering racks arrived in the last decades of the 20th century with the aim to achieve better parking characteristics. In the current century, the development of variable steering ratios has become more and more important and not only for parking. The aim of these steering systems is to combine a low speed agility increase with safe high speed behaviour. Both mechanical solutions (variable rack) and mechatronic solutions (active front steering) have been implemented in production cars.

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New Test Procedures for Handling of Vehicles with Variable Ratio Steering Systems

(25.11.2008) Vehicle handling tests have been standardised which makes it possible to compare vehicles for several items, such as understeer level. FEV uses some of these tests to establish scatter bands for all vehicle classes. The introduction
of steering systems without a fixed ratio makes that the results of these tests are no longer valid for general vehicle comparison. Therefore a method was worked out which makes the procedures fit for future steering systems as well as the existing ones.

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Objective Evaluation of Subjective Driving Impressions

(16.05.2008) In the development of passenger car driving behaviour much subjective testing is involved. Although many car manufacturers have developed objective test methods and have corresponding analyses, objective parameters which correlate one to one with the subjective rating in the international rating scale (1-very bad …. 10-excellent) are not available.

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Electronics & Mechatronics

Comparison of Model Predictions with Temperature Data Sensed On-Board from the Li-ion Polymer Cells of an Electric Vehicle

(15.05.2012) One of the challenges faced when using Li-ion batteries in electric vehicles is to keep the cell temperatures below a given threshold. Mathematical modeling would indeed be an efficient tool to test virtually this requirement and accelerate the battery product lifecycle. Moreover, temperature predicting models could potentially be used on-board to decrease the limitations associated with sensor based temperature feedbacks. Accordingly, we present a complete modeling procedure which was used to calculate the cell temperatures during a given electric vehicle trip. The procedure includes a simple vehicle dynamics model, an equivalent circuit battery model, and a 3D finite element thermal model. Model parameters were identified from measurements taken during constant current and pulse current discharge tests.

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Electric Drivetrain Testing Using Smart Green Technology

(15.05.2012) Electric Motor and Drivetrain (Electric Mobility) Testing is a critical part of bringing any electric drivetrain into production. In this paper the requirements for an electric drivetrain test cell are discussed. The implementations of such test cells are described and examples of test results are provided. In particular, the energy and power requirements for PM brushless DC dynamometers and a PM brushless Unit Under Test (UUT) connected through a common dc bus are described. Simulation of the set-up is developed using MATLAB/Simulink and verified using empirical data from the test bench. The data used represents various steady state load conditions during durability test cycles. This "Smart Green Technology" concept not only reduces the energy requirement from the grid but also eliminates the inefficiencies related to putting energy back on the grid.

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