Refine Your Search

Topic

Author

Affiliation

Search Results

Technical Paper

Downsizing of Diesel Engines: 3-Cylinder / 4-Cylinder

2000-03-06
2000-01-0990
Due to the future application of combustion engines in small and hybrid vehicles, the demand for high efficiency with low mass and compact engine design is of prime importance. The diesel engine, with its outstanding thermal efficiency, is a well suited candidate for such applications. In order to realize these targets, future diesel engines will need to have increasingly higher specific output combined with increased power to weight ratios. This is therefore driving the need for new designs of 3 and/or 4 cylinder, small bore engines of low displacement, sub 1.5l. Recent work on combustion development, has shown that combustion systems, ports, valves and injector sizes are available for bore sizes down to 65 mm.
Technical Paper

Vehicle Study on the Impact of Diesel Fuel Sulfur Content on the Performance of DeNOX Catalysts and the Influence of DeNOX Catalysts on Particle Size and Number

2000-06-19
2000-01-1877
A vehicle investigation programme was initiated to evaluate the influence of diesel fuel sulfur content on the performance of a DeNOx catalyst for NOx control. The programme was conducted with a passive DeNOx catalyst, selected for its good NOx reduction performance and two specially prepared fuels with different sulfur contents. Regulated emissions were measured and analysed during the course of the programme. The NOx conversion efficiency of the DeNOx catalyst increased from 14 to 26% over the new European test cycle when the sulfur content of the diesel fuel was reduced from 49 to 6 wt.-ppm. In addition the number and size of particles produced using 6 wt.-ppm sulfur fuel were measured by two different techniques: mobility diameter by SMPS and aerodynamic diameter by impactor. The influence of the assumed density of the particulate on the apparent diameters measured by the two techniques is discussed.
Technical Paper

Low Emission and Fuel Consumption Natural Gas Engines with High Power Density for Stationary and Heavy-Duty Application

1999-08-17
1999-01-2896
Today, natural gas engines for stationary and vehicular applications are not only faced with stringent emission legislation, but also with increasing requirements for power density and efficient fuel consumption. For vehicular use, downsizing is an advantageous approach to lowering on-road fuel consumption and making gas engines more competitive with their diesel counterparts. In SI-engines, the power density at a given compression ratio is limited by knocking, or NOx emissions. A decrease in compression ratio, lowering both NOx emissions and the risk of knocking combustion, increases fuel consumption. An increase in air-fuel-ratio, required to avoid knocking at higher thermal loading, increases boost pressure, HC and CO emissions, and mechanical loading and causes the danger of misfiring. As a result, the performance of the latest production gas engines for vehicles remains at a BMEP of 18…20 bar with a NOx emission level of 2…5 g/kWh.
Technical Paper

Analysis of the Particle Size Distribution in the Cylinder of a Common Rail DI Diesel Engine During Combustion and Expansion

2000-06-19
2000-01-1999
In the recent years diesel engine developers and manufacturers achieved a great progress in reducing the most important diesel engine pollutants, NOX and particulates. But nevertheless big efforts in diesel engine development are necessary to meet with the more stringent future emission regulations. To improve the knowledge about particle formation and emission an insight in the cylinder is necessary. By using the fast gas sampling technique samples from the cylinder were taken as a function of crank angle and analyzed regarding the soot particle size distribution and the particle mass. The particle size distribution was measured by a conventional SMPS. Under steady state conditions the influence of aromatic and oxygen content in the fuel on in-cylinder particle size distribution and particle mass inside a modern 4V-CR-DI-diesel-engine were determined. After injection and ignition, mainly small soot particles were formed which grow and in the later combustion phase coagulate.
Technical Paper

Future of Combustion Engines

2006-10-16
2006-21-0024
Increasing shortages of energy resources as well as emission legislation is increasing the pressure to develop more efficient, environmentally friendly propulsion systems for vehicles. Due to its more than 125 years of history with permanent improvements, the internal combustion engine (ICE) has reached a very high development status in terms of efficiency and emissions, but also drivability, handling and comfort. Therefore, the IC engine will be the dominant propulsion system for future generations. This paper gives a survey on the present technical status and future prospects of internal combustion engines, both CI and SI engines, also including alternative fuels. In addition a brief overview of the potential of currently intensely discussed hybrid concepts is given.
Technical Paper

Low fuel consumption and low emissions~Electromechanical valve train in vehicle operation

2000-06-12
2000-05-0018
The electromechanical valve train (EMV) technology allows for a reduction in fuel consumption while operating under a stoichiometric air-fuel ratio and preserves the ability to use conventional exhaust gas aftertreatment technology with a 3-way catalyst. Compared with an engine with a camshaft-driven valve train, the variable valve timing concept makes possible an additional optimization of cold start, warm-up and transient operation. In contrast with the conventionally throttled engine, optimized control of load and in-cylinder gas movement can be used for each individual cylinder and engine cycle. A load control strategy using a "Late Intake Valve Open" (LIO) provides a reduction in start-up HC emissions of approximately 60%. Due to reduced wall-wetting, the LIO control strategy improves the transition from start to idle.
Technical Paper

Effect of Intake Port Design on the Flow Field Stability of a Gasoline DI Engine

2011-04-12
2011-01-1284
The application of technologies such as direct injection, turbo charging and variable valve timing has caused a significant evolution of the gasoline engine with positive effects on fuel consumption and emissions. The current developments are primarily focused on the realization of improved full load characteristics and fuel consumption reduction with stoichiometric operation, following the downsizing approach in combination with turbo charging and high specific power. The requirements of high specific power in a relatively small cylinder displacement and a wide range of DI injection specifications lead to competing development targets and to a high number of degrees of freedom during engine layout and optimization. One of the major targets is to assess the stability of the combustion system in the early development phase.
Technical Paper

The Impact of Different Biofuel Components in Diesel Blends on Engine Efficiency and Emission Performance

2010-10-25
2010-01-2119
Within the Cluster of Excellence “Tailor-Made Fuels from Biomass” at RWTH Aachen University, the Institute for Combustion Engines carried out an investigation program to explore the potential of future biofuel components in Diesel blends. In this paper, thermodynamic single cylinder engine results of today's and future biofuel components are presented with respect to their engine-out emissions and engine efficiency. The investigations were divided into two phases: In the first phase, investigations were performed with rapeseed oil methyl ester (B100) and an Ethanol-Gasoline blend (E85). In order to analyze the impact of different fuel blends, mixtures with 10 vol-% of B100 or E85 and 90 vol-% of standardized EN590 Diesel were investigated. Due to the low cetane number of E85, it cannot be used purely in a Diesel engine.
Journal Article

Determination of the Cylinder Head Valve Bridge Temperatures in the Concept Phase Using a Novel 1D Calculation Approach

2010-04-12
2010-01-0499
The steady increase of engine power and the demand of lightweight design along with enhanced reliability require an optimized dimensioning process, especially in cylinder head valve bridge, which is progressively prone to cracking. The problems leading to valve bridge cracking are high temperatures and temperature gradients on one hand and high mechanical restraining on the other hand. The accurate temperature estimation at the valve bridge center has significant outcomes for valve bridge thickness and width optimization. This paper presents a 1D heat transfer model, which is constructed through the cross section of the valve bridge center by the use of well known quasi-stationary heat convection and conduction equations and reduced from 3D to 1D via regression and empirical weighting coefficients. Several diesel engine cylinder heads with different application types and materials are used for model setup and verification.
Technical Paper

Upgrade Design of the Yuchai F-6113 HD-DI Diesel Engine

2004-03-08
2004-01-1317
The Yuchai F-6113 is an inline 6-cylinder heavy duty Diesel engine, mainly for truck application with a displacement of 8.4 liters and a rated power of 258 kW. It was derived from the F-6108 with a displacement of 7.3 liters. The boundary conditions for the new crankcase were set by the existing machining line. Substantially increasing the bore diameter while keeping the bore pitch constant, was achieved by replacing the conventional top stop liner with a mid stop liner with open deck. This liner concept is rather unique for heavy duty truck engines. The two 2-valve cylinder heads, covering 3 cylinders each, were replaced by a 4-valve one-piece cylinder head. The design comprises an electronically controlled Unit Pump Injection System (UPS) with the alternative to use an inline injection pump. The engine structure was laid out for the high specific output and the peak cylinder pressure requirements for the compliance with Euro III emission legislation.
Technical Paper

Future Power Plants For Cars

2001-10-01
2001-01-3192
Environmental concern demands that emissions and fuel consumption of vehicles have to improve considerably in the next 10 years. New technologies for gasoline engines, downsizing with high boosting, direct injection and fully variable valve train systems, are being developed. For Diesel engines, improved components including piezobased injectors and particle filters are expected. In the drive train new starter-generator systems as well as automated manual transmissions are being developed. In parallel alternative fuels are investigated and the use of hybrid drives and fuel cells are developed. This paper reports the progress made in the recent years and gives a comparative assessment on the different technologies with a prediction of the introduction dates and volumes into the market.
Technical Paper

Vehicle Application of a 4-Cylinder Tumble DISI Engine

2001-03-05
2001-01-0735
SI engines with gasoline direct injection are currently the focus of development for almost all car manufacturers. After the introduction of DISI engines, first to the Japanese market and after a short time delay also in Europe, a broad variety of technical solutions for efficient stratified concepts can be stated. The targets of the development activities in this field are defined by legislation and customer's demands. The potential reduction of fuel consumption with stratified operation has to be combined with a further improvement of the full load potential of the DISI engine. A substantial part of the development activities are the fulfillment of current and future emission standards. Therefore, in order to realize a highly efficient lean operation, new technologies and strategies in the field of exhaust gas aftertreatment and vehicle application are required.
Technical Paper

Analytical and Empirical Methods for Optimization of Cylinder Liner Bore Distortion

2001-03-05
2001-01-0569
Beside the traditional prediction of stresses and verification by mechanical testing the optimization of cylinder liner bore distortion is one of today's most important topics in crankcase structure development. Low bore distortion opens up potentials for optimizing the piston group. As the piston rings achieve better sealing characteristics in a low deformation cylinder liner, oil consumption and blow-by are reduced. For unchanged oil consumption and blow-by demands, engine friction and subsequently, fuel consumption could be reduced by decreasing the pre-tension of the piston rings. From the acoustical point of view an optimization of piston-slap noise is often based on an optimized bore distortion behavior. Apart from basics to the behavior of liner bore distortion the paper presents advanced analytical and empirical methods for detailed prediction, verification and optimization of bore distortion taking into account the effective engine operation conditions.
Technical Paper

Development of a Desulfurization Strategy for a NOx Adsorber Catalyst System

2001-03-05
2001-01-0510
The aggressive reduction of future diesel engine NOx emission limits forces the heavy- and light-duty diesel engine manufacturers to develop means to comply with stringent legislation. As a result, different exhaust emission control technologies applicable to NOx have been the subject of many investigations. One of these systems is the NOx adsorber catalyst, which has shown high NOx conversion rates during previous investigations with acceptable fuel consumption penalties. In addition, the NOx adsorber catalyst does not require a secondary on-board reductant. However, the NOx adsorber catalyst also represents the most sulfur sensitive emissions control device currently under investigation for advanced NOx control. To remove the sulfur introduced into the system through the diesel fuel and stored on the catalyst sites during operation, specific regeneration strategies and boundary conditions were investigated and developed.
Technical Paper

Low Emission Concept for SULEV

2001-03-05
2001-01-1313
Today, SULEV legislation represents the most stringent emission standard for vehicles with combustion engines, and it will be introduced starting by Model Year 2003. In order to meet such standards, even higher effort is required for the development of the exhaust gas emission concept of SI engines. Beyond a facelift of the combustion system, exhaust gas aftertreatment, and the engine management system, new approaches are striven for. The principle keys are well known: low HC feed gas, high thermal load for quick light-off, exhaust system with low heat capacity and highly effective exhaust gas aftertreatment.
Technical Paper

A New Transient Elastohydrodynamic (EHD) Bearing Model Linkable to ADAMS®

2001-03-05
2001-01-1075
The new elastohydrodynamic (EHD) code developed by FEV Motorentechnik GmbH, Aachen, is designed to improve the predictability of journal bearing designs and thereby increase the reliability of safety factors in the development of highly loaded internal combustion engines. Using this tool design targets can be achieved with higher confidence levels. The developed code may be linked to commercial multibody system (MBS) codes such as ADAMS® while simultaneously representing the important characteristics occurring in transiently loaded journal bearings including elastic deformation, cavitation, and non-constant speed. Static deviations from ideal journal and bearing shell shapes caused by manufacturing and assembly processes can be considered and are substantially important in the evaluation of journal bearings. Presented is an economic bearing model approach which includes elastic bearing deformations.
Technical Paper

Oil Aeration in Combustion Engines - Analysis and Optimization

2001-03-05
2001-01-1074
Like all technical fluids, lubricants are able to solve gases. While solved gas is a neutral part of the lubricant, dissolved gas has an influence especially on the compressibility behavior. The effects of oil aeration on engine drive causes malfunctions of several components. A successful optimization of the oil circulation concerning the oil aeration presupposes a safe and reproducible measuring procedure. The FEV has developed a measurement apparatus according to the principle of the volume measurement which allows a simple but efficient oil aeration measurement.
Technical Paper

Exhaust Heat Recovery System for Modern Cars

2001-03-05
2001-01-1020
The fuel consumption and the emissions of modern passenger cars are highly affected by the fluid and material temperatures of the engine. Unfortunately, the high thermal efficiencies of Direct Injection (DI) Diesel and Spark Ignition (SI) engines cause in many driving situations low heat transfer to the engine components and especially to the oil and the coolant. In these conditions the normal operating temperatures are not achieved. Especially at low ambient temperatures and low engine loads the requirement of a comfortable cabin heating and a fast warm-up of engine oil and coolant cannot be satisfied simultaneously. To reach the required warm-up performance, an Exhaust Heat Recovery System (EHRS) will be demonstrated. Further design and optimization processes for modern cooling systems in fuel-efficient engines require numerical and experimental investigations of supplemental heater systems to meet all requirements under all circumstances.
Technical Paper

Cooled EGR - A Must or an Option for 2002/04

2002-03-04
2002-01-0962
The introduction of the new emission standards in 2002/04 for heavy-duty diesel engines requires a substantial reduction of the NOx emissions while the particulate emissions remain on a constant level. The application of cooled EGR appears to be the most common approach in order to achieve the required target, although other means such as advanced combustion systems and the application of emission control devices to reduce NOx emissions have to be taken into account as well. The purpose of this study is to investigate the potential of such alternative solutions in comparison with cooled EGR to meet the upcoming emission standards.
Technical Paper

A New TEHD Approach for Sophisticated Simulation of Journal Bearings

2001-10-01
2001-01-3367
The new Thermo-Elasto-Hydro-Dynamic (TEHD) code developed by FEV, is designed to improve the predictability of journal bearing designs and thereby increase the reliability of safety factors in the development of highly loaded internal combustion engines. Advanced analysis tools are evaluated by their performance as well as by their ease of use. High performance means on the one hand: taking into account all the important characteristics, like bearing elasticity or cavitation effects, to mention only some major parameters for modern journal bearing analysis. On the other hand: an economic run-time behavior must be a key feature concerning usability of the TEHD-demands for daily development praxis. Ease of use means also, that the TEHD model can easily be used as a plug-in routine of an already existing software package that is well known to the development departments.
X