bluuebunny/crossref_metadata_2025 huggingface dataset:
Design Process for Resin Transfer Molded, Fiber Reinforced Poppet Valves for Internal Combustion Engines
Authors: Buckley Richard T. , Miwa Jason T. , Radford Donald , Stanglmaier Rudolf H.
Published: September 2008

A project has been undertaken to design, build and test internal combustion engine poppet valves made from resin transfer molded (RTM) Fiber Reinforced Composites (FRCs). For poppet-valve engines, the valve train mass and stiffness is of particular importance because valve train natural frequency and the onset of valve float and bounce typically limit the engine operating speed. This in turn limits engine power and performance. FRC poppet valves offer the potential for substantial mass reduction as well as increased component stiffness. This enables reduced power consumption by the valve train, and increased overall engine efficiency. Resin transfer molding was chosen because of potential for high-volume production and near-net shape products. Valve design details include; identification of valve operating requirements, fiber orientations, material selection, and evaluation of potential solutions using computerized structural analysis. Mold design includes; mold configuration requirements, fiber placement strategies evaluated, intermediate validation testing done and initial prototype configuration. Results include the final valve design for an exhaust valve, fiber and matrix material selection, fiber placement strategy, and mold configuration. Plans for additional validation testing are presented.
Steady-State Intake Flow in a High-Performance V-Twin Engine
Authors: Guy Ryan K. , Stanglmaier Rudolf H.
Published: September 2008

The design of intake ports for high-performance internal combustion engines has traditionally relied on steady-state flow benches and prototype core boxes. In this study, Computational Fluid Dynamics (CFD) methods were employed to gain further insight into the characteristics of a high-performance motorcycle engine. In this particular engine configuration, the throttle is located in very close proximity to the intake port, and the effects of throttle position on the intake flow characteristics were examined. This study shows that steady-state CFD analysis can be used in combination with traditional flow optimization techniques to provide further insight for cylinder head development. The intake flow behavior in this engine was found to vary considerably as a function of valve lift and throttle position. It was found that at low valve lifts the intake flow is relatively uniform around the periphery of the intake port, but at high valve lifts the flow into the cylinder is biased towards the top of the intake port. This results in a tendency to promote tumble at high valve lifts, but not at low valve lifts. Small throttle opening angles were found to magnify the flow biasing effect at high valve lifts.
Friction Reduction by Piston Ring Pack Modifications of a Lean-Burn 4-Stroke Natural Gas Engine: Experimental Results
Authors: Quillen Kris , Stanglmaier Rudolf H. , Moughon Luke , Takata Rosalind , Wong Victor , Reinbold Ed , Donahue Rick
Published: September 2008

A project to reduce frictional losses from natural gas engines is currently being carried out by a collaborative team from Waukesha Engine Dresser, Massachusetts Institute of Technology (MIT) and Colorado State University (CSU). This project is part of the Advanced Reciprocating Engine System (ARES) program led by the US Department of Energy. Previous papers have discussed the computational tools used to evaluate piston-ring/cylinder friction and described the effects of changing various ring pack parameters on engine friction. These computational tools were used to optimize the ring pack of a Waukesha VGF 18-liter engine, and this paper presents the experimental results obtained on the engine test bed. Measured reductions in friction mean effective pressure (FMEP) were observed with a low tension oil control ring (LTOCR) and a skewed barrel top ring (SBTR). A negative twist second ring (NTSR) was used to counteract the oil consumption increase due to the LTOCR. The LTOCR and SBTR each resulted in a ∼ 0.50% improvement in mechanical efficiency (ηmech).
Simultaneous Reduction of Oxides of Nitrogen and Smoke Emissions by Using EGR Combined With Particulate Trap in a DI Diesel Engine
Authors: Anand R. , Mahalakshmi N. V.
Published: September 2008

Exhaust gas recirculation (EGR) combined with particulate trap technology has proven to reduce nitrogen oxides (NOx) and smoke emissions simultaneously at relatively low cost compared to other reduction strategies. An experimental study was conducted on a single cylinder, direct injection (DI) diesel engine to study the effect of EGR on engine performance and emissions under constant speed of 1500 rpm at various loads. In the present work hot and cool EGR were used to control the formation of NOx in a D.I diesel engine. The findings of both hot and cool EGR are discussed and compared at full load condition corresponding to the maximum allowable EGR proportion of 15%. It is found that cool EGR has a substantial reduction in NOx and smoke emissions compared to hot EGR. Based on the above result it is found that suitable particulate trap which is cost effective and high trapping efficiency is needed before the EGR cooler to reduce the smoke emissions to meet the emission standards. In the present study a substrate made of clay material was used in the particulate trap. They were made into spheres and coated with copper and zinc oxide catalyst material. The results have shown that EGR combined with particulate trap simultaneously reduces the NOx and smoke emissions by 63% and 42% respectively where as it increases brake specific fuel consumption by 10% compared to baseline mode.
Ion Sensing for Off-Highway Diesel Engines to Meet Future Emissions Regulations
Authors: Adair Jessica , Viele Matthew , Van Dyne Ed
Published: September 2008

Emissions regulations for off-highway engines are tightening towards those of on-highway engines. Present designs will not be able to meet these more stringent regulations because of their use of mechanical fuel injection timing control; more advanced timing control will be required. Ion sensing combined with variable fuel injection timing may help these engines meet the emissions requirements without the drastic price increase that usually accompanies a switch to advanced fuel injection technology. Ion sensing can detect the start of combustion and this signal can be used for closed loop control for the injection timing. The integrity of the ion signal is highly dependent on combustion chamber geometry, sensor placement, and even the polarity of the charge across the sensor. Optimizing all of these effects could improve the detection of the start of combustion from an ion sensor to less than one crank angle degree and provide a signal for closed loop control of the injection timing.
Tumble Flow Measurements Using Three Different Methods and Its Effects on Fuel Economy and Emissions
Authors: Kim Myoungjin , Lee Sihun , Kim Wootae
Published: September 2008

In-cylinder flows such as tumble and swirl have an important role on the engine combustion efficiencies and emission formations. In particular, the tumble flow, which is dominant in-cylinder flow in current high performance gasoline engines, has an important effect on the fuel consumptions and exhaust emissions under part load conditions. Therefore, it is important to know the effect of the tumble ratio on the part load performance and optimize the tumble ratio of a gasoline engine for better fuel economy and exhaust emissions. First step in optimizing a tumble flow is to measure a tumble ratio accurately. In this research the tumble flow was measured, compared and correlated using three different measurement methods: steady flow rig, 2-Dimensional PIV, and 3-Dimensional PTV. Engine dynamometer test was performed to find out the effect of the tumble ratio on the part load performance. Dynamometer test results of high tumble ratio engine showed faster combustion speed, retarded MBT timing, higher exhaust emissions, and a better lean burn combustion stability. Lean limit of the baseline engine was expanded from A/F=18:1 to A/F=21:1 by increasing a tumble ratio using MTV.
Simulation of Accessory Drive Belt Concerning to Slippage and Transversal Vibration
Authors: Takagishi Hiroshi , Yoneguchi Hiroshi , Sakamoto Daichi , Nagakubo Atsushi
Published: September 2008

A simulation method was proposed to predict the slippage and transversal vibration of the accessory drive belt. To reproduce these phenomena, the accessory drive belt was represented by a section-by-section model in which the belt was replaced by a finite number of masses and springs using multi-body dynamics simulation. In this model, the belt was able to vibrate in both the direction of advance and the direction perpendicular to it, and a friction contact element was defined between the pulley and the belt. The coefficient of friction was made variable with respect to the slippage speed to enable stick and slippage to be predicted. This method allows for accurate simulation of the amount of belt slippage and the amplitude of transversal vibration, thus enabling the optimum belt layout to be determined at the design stage.
Comparative Particulate Trap Performance Using Fischer-Tropsch and Conventional Diesel Fuels in a Modern CI Engine
Authors: Sappok Alexander G. , Wong Victor W.
Published: September 2008

Increasingly stringent emissions regulations aimed at drastically reducing particulate emissions from diesel engines pose one of the greatest challenges to diesel engine development today. Furthermore, engine manufacturers are finding it more and more difficult to comply with these new regulations through in-cylinder optimization alone. As a result, exhaust after-treatment systems, namely diesel particulate traps, present additional means for meeting these strict requirements. A previous study demonstrated the potential for diesel particulate emissions reduction using neat Fischer-Tropsch (F-T) fuel and blends. The absence of sulfur in F-T fuels permits the use of more aggressively catalyzed traps, as sulfur poisoning is not an issue. Furthermore, the reduced particulate emissions of F-T fuels leads to increased time between trap regenerations, which in conjunction with advanced catalyst formulations reducing the temperatures required to initiate regeneration, may provide substantial improvements in trap durability and performance. However, the deposition of particulates from F-T fuels on the trap substrates and loading and regeneration of the trap with F-T particulates and F-T fuel have not been adequately addressed. In this study a 2002, six-cylinder, 5.9 liter, Cummins ISB 300 diesel engine, outfitted with a fully instrumented particulate trap, was subjected to a subset of the Euro III 13-mode test cycle under steady-state operating conditions. In order to investigate the fundamental fuel effects on particulate trap loading characteristics, un-catalyzed Cordierite substrates were loaded with particulates generated from neat F-T diesel and a low sulfur diesel (LSD). Trap temperature, pressure drop, particulate emissions, and gaseous exhaust composition were monitored before and after the trap. The use of F-T fuel significantly extended the trapping period and reduced the regeneration frequency as compared to the LSD. Based on the differences in emissions and fuel composition, explanations for the observed differences in the trap performance were developed.
Advanced Elastohydrodynamic Analysis of Journal Bearings in IC Engines With a Multi-Body System Approach
Authors: Ma Ming-Tang , Loibnegger Bernhard , Herster Paul
Published: September 2008

This paper presents a rigorous analysis of the elastohydrodynamic (EHD) lubrication of journal bearings in internal combustion (IC) engines. The approach treats a set of radial slider (plain journal) bearings as a system or a subsystem. Thus, they can be simulated simultaneously, and hence the system effect is included. The analysis considers both the elasticity and dynamics of the connected parts such as the cylinder block (or main bearing walls), crankshaft and conrod. Both local vibration and global motion of these elastic parts are modelled by a multi-body system (MBS) approach. Hence, the EHD behaviour of engine bearings is simulated in a realistic manner.
A New Design for Inlet Diffuser of Automotive Catalytic Converter
Authors: Saidi M. H. , Mozafari A. A. , Ghasemi A.
Published: September 2008

The monolithic catalytic converter still is the main pollution control device for modern vehicles in order to reach the ever-increasing legislative demands for low emission standards. The catalytic converters require a large expansion from the exhaust pipe to the front face of the monolith. Unfortunately, packaging constraints often do not permit the use of long diffusers. Hence, flow separation within the diffuser leads to a non-uniform flow distribution across the monolith. A uniform flow distribution at the inlet monolith face is favorable for the conversion efficiency as well as the durability of the catalytic converter. Therefore the main problem is to optimize the flow distribution at the catalytic converter. It should be noted that due to flow maldistribution in an enlarged inlet of catalytic converter, some part of the monolith would be non effective. In this research a new design for inlet diffuser of catalytic converter has been proposed and fabricated. The new inlet diffuser is composed of some tube to tube cones that distribute the flow uniformly at the entrance face of monolith. Temperature, pressure drop and concentration of pollutants, before and after catalyst, have been measured. The results show that the new design for inlet diffuser tends in less uniform temperature field at the entrance of monolith but the flow distribution becomes more uniform and an increased conversion efficiency of catalyst will be obtained.
On-Line Measurements of Engine Oil Aeration by X-Ray Absorption
Authors: Manz Devon , Cheng Wai
Published: September 2008

The oil aeration in a V-6 spark-ignition passenger car engine under motoring condition was measured by the X-ray absorption method in the speed range of 2000–6000 rpm. Measurements were made at different locations in the sump representing the state of the oil at (1) the pump inlet, (2) the head return and (3) the timing chain return. The aeration of the block return was estimated from these measurements. At a fixed engine speed, the aeration (in % volume of air) of the head return and the chain return were about the same, and they were approximately twice the value found in the block return. This distribution did not change with engine speed. When weighted by the flow rate, however, the block flow contributed to 55% of the aeration at the pump inlet; the total contribution of the head return and the chain return was 45% (36% from head return and 9% from chain return). Further aeration observations were made by comparing the cases with and without the oil sump windage tray in place. When the tray was removed, aeration at the pump inlet was found to increase by less than 30% for all speeds.
Cumulative Microslip in Conrod Big End Bearing System
Authors: Ligier Jean-Louis , Antoni Nicolas
Published: September 2008

High combustion gas pressure and mass reduction of modern automotive engines have generated new problems in mechanical assemblies. For example, it is now common to observe bearing shell rotation in the conrod of automotive prototype engines at the design stage. The consequence is sometimes the seizure of the bearing due to the presence of the joint face relief in the loaded area. Physically, the bearing shell rotation results from cumulated microslip between the bearing and the conrod. To have a better physical approach of the phenomenon and propose design recommendations, we have performed analyses based on the strength of material theory and numerical modellings. These tools permit us to obtain simple models allowing an easier mechanical understanding as well as an analysis of sensitivity to different parameters. The main results presented in this paper are: • The basic description of the phenomenon, • The modelling of the conrod, its sensitivity to deformation and numerical validation, • The analysis of the microslip between the bearing shell and the conrod, • The sensitivity analysis with respect to conception and physical parameters.
Analysis of a HSDI Diesel Engine Intake System by Means of Multi-Dimensional Numerical Simulations: Influence of Non Uniform EGR Distribution
Authors: Cantore Giuseppe , De Marco Carlo Arturo , Montorsi Luca , Paltrinieri Fabrizio , Rinaldini Carlo Alberto
Published: September 2008

In order to comply with stringent pollutant emissions regulations a detailed analysis of the overall engine is required, assessing the mutual influence of its main operating parameters. The present study is focused on the investigation of the intake system under actual working conditions by means of 1D and 3D numerical simulations. Particularly, the effect of EGR distribution on engine performance and pollutants formation has been calculated for a production 6 cylinder HSDI Diesel engine in a EUDC operating point. Firstly a coupled 1D/3D simulation of the entire engine geometry has been carried out to estimate the EGR rate delivered to every cylinder; subsequently the in-cylinder flow field has been evaluated by simulating the intake and compression strokes. Finally the spray and combustion processes have been studied accounting for the real combustion chamber geometry and particularly the pollutants formation has been determined by using a detailed kinetic mechanism combustion model. The 1D/3D analysis highlighted a significant cylinder to cylinder EGR percentage variation affecting remarkably the pollutant emissions formation, as evaluated by the combustion process simulations. A combined use of commercial and in-house modified codes has been adopted.
Field Experience and Laboratory Analysis of Oxidation Catalyst on Dual Fuel Engines
Authors: Williams Shazam , Naseri Mojghan , Aleixo Joe , Sandelin Kristoffer
Published: September 2008

A DCL oxidation catalyst for exhaust-gas cleaning has been field tested on a Wa¨rtsila¨ 50 series dual-fuel engine during 5000 hours of continuous operation in an end-user power plant application. The engine has been designed for continuous operation on natural gas (NG), light fuel oil (LFO) as well as heavy fuel oil (HFO), thus giving the consumer a wide variety of fuelling options. All three fuels were used at some point during the 5000 hours field trial. These fuels have different properties such as differing levels of sulphur and ash contents that affect the abatement efficiencies of the oxidation catalyst. A detailed study was performed to understand the effect of different fuels, lube oil poisoning and long running hours on the abatement performance of the oxidation catalyst. The oxidation catalyst was equipped with sample cores that were exchanged during scheduled engine maintenance periods. This allowed parallel field and laboratory evaluation of the emissions abatement and the quantity of lube oil deposits on the catalyst at successive intervals of engine running hours. We will show that the combination of the dual fuel engine and the oxidation catalyst is very robust, even for the different fuels, and it gives low emissions.
Development of a Fiber Delivered Laser Ignition System for Natural Gas Engines
Authors: Yalin Azer P. , Reynolds Adam R. , Joshi Sachin , Defoort Morgan W. , Willson Bryan , Matsuura Yuji , Miyagi Mitsunobu
Published: September 2008

Laser ignition is viewed as a potential future technology for advanced high-efficiency low-emission natural gas engines. However, in order to make laser ignition systems more practical, thereby enabling them to transition from the laboratory to industrial settings, there is a need to develop fiber optically delivered ignition systems. Recent work at Colorado State University has shown the possibility of using coated hollow fibers for spark delivery and has demonstrated laser ignition and operation of a single engine cylinder using hollow fiber delivery. In order to practically operate a multiple cylinder engine, we envisage a simple and low-cost system based upon a single laser source being delivered (“multiplexed”) through multiple fibers to multiple engine cylinders. In this paper, we report on the design, development, and initial bench-top testing of a multiplexer. Bench-top testing showed that the multiplexer can be positioned with the required accuracy and precision for launching into fiber optics, and can be switched at the relatively high switching rates needed to operate modern natural gas engines. Another test employed the multiplexer to alternately launch laser pulses into a pair of hollow fibers in a way that allows spark creation downstream of the fibers.
Preliminary Investigation Into Comparative Performance of Titanium Based Coatings for Automotive Applications Using Biodiesel Blend and Diesel
Authors: Shukla Mritunjay Kumar , Agarwal Avinash Kumar , Garg Ashish
Published: September 2008

In order to reduce emissions and improve performance, engine designers have increased fuel injection pressures to improve fuel atomization. This leads to increased mechanical loads on the injection system requiring finer clearances that must be maintained between the plungers and bores in order to maintain diesel fuel injection quality. The reduction in diesel fuel sulfur levels required for meeting the emission legislations result in decreased fuel lubricity. In addition, due to unprecedented rise in the crude oil prices, biofuels are getting increasing attention worldwide. However, this also needs evaluation of the performance of the engine parts, especially the friction and wear in injection systems. In the present study we have investigated three titanium based physical vapour deposition (PVD) coatings (TiN, TiAlN, TiCN) used in two different environments namely mineral diesel and biodiesel, both containing 1% water. Commercially available thin-film ion-bonded coatings of above mentioned inter-metallic compounds, grown on steel balls were subjected to wear under stable load conditions in a custom build rotating disk wear tester. Some of the interesting findings of this experimental investigation may be instrumental in providing input for the development of hard, corrosion-resistant coatings for parts of Injector and fuel pumps of internal combustion engines using different fuels, especially biodiesel fuels.
Research on the Electromagnetic Valve Used in Medium Pressure Common Rail Electronically Controlled Fuel Injection System
Authors: Wang Zhigang , Yang Jianguo
Published: September 2008

A new kind of electromagnetic valve [1], with great flow and fast speed, used in the medium pressure common rail electronically controlled fuel injection system of diesel engine is introduced for the first time. It is a kind of Two-position, Three-way Valve (TTV) that consists of a valve body, an outer valve rod and two inner valve rods. The electromagnet can generate great electromagnetic force because of its assembled magnetic fields. It actuates the outer valve rod from its closed-position to the open-position rapidly. A spring is used to push it back. Fuel injection begins when the outer rod is in the open position and ends in the closed. The inner and outer valve rods with taper valve port replace the traditional configuration and decrease the difficulties in machining. Finite element method has been used to analyze the electromagnet’s electromagnetic fields. Static characteristics of the electromagnet are calculated. Some factors such as working area, coil turns, core number, armature depth and iron material that influence the magnetic force are discussed in detail. The magnetic material and the electromagnet dimensions are optimized according to calculation results. Meanwhile, the leakage between the valve body and the outer valve rod, the leakage between the outer valve rod and left-inner valve rod and the leakage between the outer valve rod and the right-inner valve rod are also studied by the finite element method. Key part that causes the leak during operation has been found out and improvement is carried out. Influences of the TTV to the injection timing and the injection amount are analyzed in detail based on the Fuel Injection Test Platform (FITP) in the end.
Performance of Natural-Gas-Fueled Engines Heading Towards Their Optimum
Authors: Klimstra Jacob , Hattar Christer
Published: September 2008

The efficiency of natural-gas-fuelled reciprocating engines increased from an average value of 35% in the year 1990 to over 46% for large-bore engines in 2005. Increasing the load (bmep) of the engines helped to reduce the negative effect of friction losses on efficiency and to reduce the relative heat losses from the combustion process. Doubling the cylinder bore decreased the heat escaping from the cylinder process by about a factor two. The analyses show that further increases in bmep and bore diameter will hardly help in achieving a better efficiency. Reduction of the friction losses appears the best path to follow for an even higher efficiency. The authors do not expect that the efficiency of an Otto-cycle gas engine will substantially exceed 49%.
MotoGP 2007: Criteria for Engine Optimization
Authors: Mattarelli Enrico
Published: September 2008

The paper proposes some design criteria for the MotoGP engines, complying with the FIM 2007 Technical Regulations. Five configurations have been considered: 3-cylinder in-line, 4-cylinder in-line, and three V-engines with 4, 5 and 6 cylinders. All the analyzed solutions have been optimized from a fluid-dynamic point of view, by means of 1D engine cycle simulations. Then, the engines are compared in terms of full load performance, at steady conditions. Finally, the influence of engine performance, along with operations regularity and motorbike weight, is assessed by means of a lap time simulator, developed by the author on the base of real data. The best configurations turned out to be the 4-cylinder engines, while 3-cylinder and 5-cylinder are quite penalizing.
Performance and Emissions Characteristics Investigation of a Bi-Fuel SI Engine Fuelled by CNG and Gasoline
Authors: Shamekhi Abazar , Khatibzadeh Nima , Shamekhi Amir H.
Published: September 2008

Nowadays, increased attention has been focused on internal combustion engine fuels. Regarding environmental effects of internal combustion engines particularly as pollutant sources and depletion of fossil fuel resources, compressed natural gas (CNG) has been introduced as an effective alternative to gasoline and diesel fuel in many applications. A high research octane number allows combustion at higher compression ratios without knocking and good emission characteristics of HC and CO are major benefits of CNG as an engine fuel. In this paper, CNG as an alternative fuel in a spark ignition engine has been considered. Engine performance and exhaust emissions have been experimentally studied for CNG and gasoline in a wide range of the engine operating conditions.
Thermal Spraying of Aluminium Cylinder Bores by the Ford PTWA Spray Process
Authors: Verpoort C. , Blume W. , Ehrenpreis R. , Silk M. , Polich W. , Cook D. , Kowalsky K. , Bobzin K. , Schlaefer Th. , Zwick J. , Ernst F. , Schwenk A. , Nassenstein K.
Published: September 2008

One of the main drivers in the automotive industry is the reduction in fuel consumptions and emissions. In order to achieve these goals, the weight of the engine block as well as the friction in the cylinder bore has to be optimized. This paper describes the FORD PTWA (Plasma Transferred Wire Arc) thermal spray process that protects the aluminum cylinder bore surface against wear by a thermal spray coating. The PTWA technology was originally developed for the application in gasoline V8 engines and it will be shown in this paper how this process can be modified to apply nano-material to produce high-wear resistant, low-friction coatings for highly loaded engine blocks for future demands. A large German BMBF “Nanomobile” Research Program was started in 2005 with 13 partners (DaimlerChrysler, Opel, Porsche, Ford, Gehring, Federal Mogul, GTV Thermal Spray Systems, DURUM, RWTH University and other institutes) in order to develop next generation nano-material coatings for cylinder bores.
Advantages and Limitations of Lead-Free Bearing Materials
Authors: Walker Rick , Aufischer Rainer , Mergen Robert , Ciacci Dave
Published: September 2008

Due to strict lead recycling regulations put upon discarded automobile engines, removing lead from new automotive engines became essential. Removing lead found in batteries from discarded automobiles is fairly straight-forward and inexpensive; however, much labor and cost is associated with removing lead containing engine bearings. Due to the relatively light loading applied to automotive gas engine bearings, lead-free aluminum alloys have been developed. Many experts predict that this lead-free trend will carry over to non-automotive bearings as well. Many of these non-automotive engines are run on diesel fuel and have much higher loading on the bearings. The current generation of lead-free aluminum alloys just cannot carry the loads required by these engines. Therefore, there has been efforts on developing lead-free copper based bearing alloys. This paper reviews one process that was undertaken to develop lead-free copper based alloy to be used in these highly loaded, non-automotive lead-free engine bearing types. This process included a fundamental understanding of the tribological role of lead in copper based bearing alloys, as well as a thorough performance screening of lead-free bearings types based on this lead-free lining and a comprehensive review of the test results. Also included in this paper are some future development plans in the world of lead-free copper based bearings alloys.
Study of Combustion Anomalies of H2-ICE With External Mixture Formation
Authors: Ciatti Stephen A. , Wallner Thomas , Ng Henry , Stockhausen William F. , Boyer Brad
Published: September 2008

Although hydrogen is considered one of the most promising future energy carriers, there are several challenges to achieving a “hydrogen economy,” including finding a practical, efficient, cost-effective end-use device. Using hydrogen as a fuel for internal combustion engines is seen as a bridging technology toward a large-scale hydrogen infrastructure. To facilitate high-efficiency, high-power-density use of hydrogen with near-zero emissions in an internal combustion engine, detailed analysis of the hydrogen combustion process is necessary. This paper presents thermodynamic results regarding engine performance and emissions behavior during investigations performed on a single-cylinder research engine fueled by pressurized gaseous hydrogen. Avoiding combustion anomalies is one of the necessary steps to further improve the hydrogen engine power output at high-load operation while, at the same time, reducing fuel consumption and emissions during part-load operation. The overall target of the investigations is an improved combustion concept especially designed for hydrogen-engine-powered vehicles. Future activities include performing optical imaging of hydrogen combustion by using an endoscope. We will also investigate supercharged external mixture formation, as well as hydrogen direct-injection operation.
Experimental and Theoretical Study of Injection Timing on Performance and Exhaust Emissions in a Port-Injected Gasoline Engine
Authors: Movahednejad E. , Ommi F. , Hosseinalipour M. , Samimi O.
Published: September 2008

For spark ignition engines, the fuel-air mixture preparation process is known to have a significant influence on engine performance and exhaust emissions. In this paper, an experimental study is made to characterize the spray characteristics of an injector with multi-disc nozzle used in the engine. The distributions of the droplet size and velocity and volume flux were characterized by a PDA system. Also a model of a 4 cylinder multi-point fuel injection engine was prepared using a fluid dynamics code. By this code one-dimensional, unsteady, multiphase flow in the intake port has been modeled to study the mixture formation process in the intake port. Also, one-dimensional air flow and wall fuel film flow and a two-dimensional fuel droplet flow have been modeled, including the effects of in-cylinder mixture back flows into the port. The accuracy of model was verified using experimental results of the engine testing showing good agreement between the model and the real engine. As a result, predictions are obtained that provide a detailed picture of the air-fuel mixture properties along the intake port. A comparison was made on engine performance and exhaust emission in different fuel injection timing for 2600 rpm and different loads. According to the present investigation, optimum injection timing for different engine operating conditions was found.
On the Use of VVT Strategy for the Maximum Volumetric Efficiency in Turbocharged Diesel Engines
Authors: Ghazi Mir Saied S. Ahmad , Shamdani Amir H. , Shamekhi Amir H.
Published: September 2008

This paper presents a variable valve lifting methodology for turbocharged diesel engines. For this purpose, the diesel engine is modeled based on a modified mean-value engine modeling. An optimal control strategy is used for maximum volumetric efficiency acquirement. Using camless valve train strategy makes better fuel economy and improved air intake characteristics throughout the engine operating map. The system is capable of continuously, independently and virtually controlling all standard parameters of variable valve motion. This permits optimization of valve events for any operating condition without compromise. The optimized intake valve profile is determined, to have the best volumetric efficiency and proper operation for each running condition based on the existing model make use of numerical techniques. The model used in this paper is validated using simulation results of references. The model treats the cylinder and the manifolds as thermodynamic control volumes by using the filling and emptying method, solving energy and mass conservation equations with sub models for intake manifold, variable valve timing, cylinder breathing dynamics and turbocharger including turbine and compressor. This model is a crank angle based dynamic nonlinear model of a four-cylinder turbocharged (TC) diesel engine, which captures the interactions among the VVT actuation, the turbocharger dynamics and the cylinder-to-cylinder breathing characteristics. The model have been implemented in Matlab/Simulink and tested. This work shows the results obtained for air management control in a turbocharged diesel engine, specifically, manifold pressure and air mass flow. These variables are often required to achieve better power performance and lower emissions.
A Combined Simulation and Experimental Study on Optimization Intake Manifold of Spark Ignition Engine
Authors: Samimi Abiane Omid , Mirsalim Mostafa , Ahmadi Mahdi , Karbasi Majid
Published: September 2008

This paper presents the results of an investigation into the comparison between measured and simulated intake system dynamics of the Peugeot XU7-L3 engine. Simulation and Experimental tests are conducted at full throttle operating conditions ranging from 1500 to 6000 rpm under firing operation. Comparisons of basic engine performance parameters, showed a good correlation between measurement and simulation.
Modeling of Variable Intake Valve Timing in SI Engine
Authors: Ghazi Mir Saied S. Ahmad , Jazayeri S. Ali , Shamekhi Amir H.
Published: September 2008

In internal combustion engines valve events and timings are among the most important parameters which have a major influence on the engine’s operation and volumetric efficiency. By using camless valvetrain strategy, improvement in fuel economy as well as an increase in entering air charge is found throughout the engine map with the largest benefits arising from low speed operating conditions. The system offers a continuously variable and independent control of virtually all parameters of valve motion. This permits optimization of valve events for each operating condition without any compromise. In this paper we describe a phenomenological model for an unthrottled operation of a camless intake process of spark-ignited (SI) engine. Initially the cylinder breathing dynamics is modeled and results are validated with experimental data of a conventional engine with cam-driven valve profile during unthrottled operation. Then we determine the most optimized intake valve profile in order to have the most volumetric efficiency and proper operation for each operating condition based on the existing model and using numerical techniques.
Thermomechanical Fatigue Life Prediction of Cast Iron Cylinder Heads
Authors: Trampert Stefan , Go¨cmez Taner , Quadflieg Franz-Josef
Published: September 2008

While the deformation and damage behavior of aluminum cylinder heads under complex thermal mechanical loading has been the subject of numerous studies in the past, cast iron cylinder heads have been in the focus of thermomechanical fatigue (TMF) only to a minor extent. In this paper, a feasible procedure is presented to set-up material models and estimate service life of cast iron cylinder heads under variable thermomechanical loading conditions by the use of CAE tools. In addition, the influence of thermal load and mechanical constraints on TMF life span is shown. A specimen model is used for parameter identification in material model set-up and a cylinder head model is used for correlation with cracking phenomena. Investigation of different thermomechanical load influences is conducted on the cylinder head model. The principal strain and energy based fatigue criteria are used in assessment of TMF lifetime for the cast iron family and material specific evaluation procedures are pointed out. The results highlight the importance of exact definitions of the boundary conditions and underline the sensitivity of TMF lifespan of cast iron cylinder heads with respect to the defined boundary conditions. Considering this sensitivity, an approach conforming to the engine development requirements is proposed. It is shown that both the crack location and fatigue lifetime are predicted with high accuracy.
Study of the Piston System Structure of Advantageous to Low Friction and Economizing Energy
Authors: Yu Z. Z. , Xie Y. B.
Published: September 2008

There must be an end gap in the piston ring because of the need of mounting and compensation for diameter after the wear of ring. Richardson’ and many author’ studies have showed the effects of the end gap to blowby and oil consumption, especially in the presence of ring or liner wear. This problem has influenced the effective utilization of the fuel energy for many years. Moreover the ring will rotate in the working cycle of engine. Once the end gaps of two compression rings come to the site of superposition, the shortest passage of gas flow is formed and blowby will be increased. The deflection of crankpin and rotation of piston were calculated according to the analytical model based on the torque transmission theory of crankshaft. The positive and negative deflections of crankpin result in the reciprocating rotation of piston in the IC engine working cycle. The peak values of deflection and rotation are in the vicinity of crank angle position of deflagration. Because the clingy moment of compression rings are less than rotational resistance moment in a few section of crank angle, they are unable to keep synchronism with piston and the rotations opposite to piston occur. The rotation angle of the second compression ring is more than that of the first ring. The superposition of the end gaps of two compression rings comes about when they turn to the same angle position. Based on above study, the structure of one compression ring in piston system should be widely used, which is in favor of reduction of friction and engine weight, pushing forward the lightweight process, being useful to the decrease of fuel consumption and emission. The pressure of combustion gas will not remarkably descend in this structure. The problem of ring suspension and pressure release in the first ring land can be resolved. Two types of rings with complete seal and economizing energy design are showed for the structure of one ring, which will also avoid the increase of end gap after the rings are worn.
Powerful, Clean Yet Silent
Authors: Alt Norbert , Sonntag Hans-Dieter , Heuer Stefan , Schlitzer Michael
Published: September 2008

Internal combustion engine development nowadays is characterized by decrease of exhaust gas emissions and increase of specific power and torque. Combustion noise excitation and fuel consumption have to be decreased in parallel. All these goals can be met today due to the development of advanced combustion systems and the increased flexibility of fuel injection system and ECU. But hereby, combustion system development and vehicle application have become more complex in recent times. A precise and simple description of ‘combustion noise’ is not trivial in this context. The customer subjective impression of e.g. diesel knock intensity, at vehicle interior and exterior, is the relevant value for this. Combustion noise excitation today is described by using the in-cylinder pressure based FEV CSL. Full calibration NVH potential is explored hereby, while meeting the emission and fuel consumption targets. FEV CSL-CAL is the in-house developed tool for NVH related vehicle calibration. All important ECU parameters are optimized simultaneous under the customer-relevant driving conditions hereby. Additionally, sound quality objective parameters for judgment of subjective combustion noise impression — FEV SQO — are used to find the optimal calibration map, for steady state as well as for cold start and during acceleration. By all this, combustion noise is described well and can be optimized toward customer expectation.
Trend-Setting Engine Architecture for HD Truck Engines Driven by Future Development Targets
Authors: Neitz Michael , Quadflieg Franz-Josef , Ruhkamp Ludger , Steffens Christoph , Wartmann Peter
Published: September 2008

The paper is a contribution to the discussion about a suitable future engine architecture, which has to cope with two contrary demands: the high mechanical and thermal loads in the engine and the need for a cost efficient, light weight engine design. Based on combustion related requirements of future emission legislation and expected performance requirements, a possible scenario of engine types and displacements is described. Features of a proposed bottom and top end concept — such as liner and crankcase concept, cylinder head bolt pattern, cylinder head concept, and suitable materials — are discussed, with the target to define a solution especially capable of high cylinder peak pressures and cost efficient at the same time.
The Roller Bearing Engine: A Cost Effective Contribution to CO2-Reduction
Authors: Tiemann Christof , Orlowsky Kolja , Steffens Christof , Bick Werner , Kalenborn Markus
Published: September 2008

The investigations and developments described in this article substantiate the potential for reduction of fuel consumption and the general feasibility of a roller bearing crank train in an internal combustion engine. An improvement of fuel consumption of 5.4% (NEDC) resulting from reduced friction was proven on the basis of a given 1.6L 4-cylinder plain bearing engine converted to roller bearings. By means of subsequent calculations and simulations, the parameters for optimisation of the engine acoustics and durability were identified. Based on these findings, an advanced test engine was set up. Measurements with this generation 2 roller bearing engine demonstrate the expected significant improvement of NVH behaviour. In parallel to the investigations with the generation 2 prototype which had to be a compromise with regard to robustness due to the requirement for a quickly realisable and feasible application, a completely new roller bearing bottom-end concept (generation 3) was developed. This new design meets the main requirements of optimal roller bearings while also taking the boundary conditions for high-volume production into account. The essential attributes of this generation 3 roller bearing crank train concept are the single-piece conrod and main-bearing pedestals which are threaded onto a crankshaft with detachable counterweights. The extra cost of EUR 50.- to 70.- for these roller bearing engine concepts is on a low level compared to the achieved reduction in fuel consumption.
Filtration of Lubrication Oil in Railway Applications
Authors: Schmitz Stefan , Lennartz Ru¨diger
Published: September 2008

Traditional designs, using cartridge filters for full-flow filtration, protect medium speed and high speed diesel engines from wear and keep the concentration of abrasive particles in the oil system down by collecting them out of the circulating oil flow. After several hundred running hours the filtration surface is saturated, the cartridges get exchanged and disposed. State of the art automatic filters protect the engines against wear with the same efficiency as the cartridge filters but the backflushing mechanism keeps the filtration surface clean and the lubrication circuit remains maintenance free. The lifetime of filter elements lasts during time before overhaul (TBO) of the engine itself and is at least 24,000 hrs. The job to discharge the particles out of the system is done by highly efficient centrifugal oil cleaners in by-pass operation which separate not only the particles retained by the automatic filter but also very fine solids like soot. Figure 1 shows an automatic filter in cooperation with two centrifugal oil cleaners build into the silhouette of the engine.
Diesel Generator Owner’s Groups Improve Power Plant Operations and Maintenance
Authors: Killinger Arthur G. , O’Connell Mark J.
Published: September 2008

Diesel generator sets are installed at nuclear power plants to provide emergency power to ensure safe shut down of the reactor in the event of an accident. In the United States, all nuclear power plants belong to one of six different Diesel Generator Owner’s Groups. Some groups have been in existence for over 17 years and the members have all benefited from their participation. In the past three years, the Diesel Generator Owner’s Group concept has spread and two new groups have been formed among a number of independent diesel generator power plant owners and operators in Latin America and the Caribbean area. This paper describes: (1) how electric power plants, large and small, have formed Diesel Generator Owner’s Groups, (2) how better working relationships between the power plants and the engine manufacturer have been established, and (3) how involvement in a strong owner’s group provides significant benefits to the members. The primary goal of the groups is to increase reliability and improve performance of the diesel engines at the respective power plants. Typical objectives of effective Diesel Generator Owner’s Groups include: • Provide a mechanism for rapid resolution of specific problems with the diesel engine, generator and auxiliary systems, • Provide improved communications among the owners and the diesel generator manufacturer, • Develop a group of “technical experts” and expand that knowledge base to other plant personnel, and • Identify methods to improve diesel engine generator and overall power plant performance, reliability, availability and safety. Active participation in Diesel Generator Owner’s Group has resulted in real payback for the owners and manufacturers alike. To illustrate this fact, several unique diesel engine problems are described along with the approach the Diesel Generator Owner’s Groups used to resolve the problems. Finally, overall diesel generator reliability and availability have improved. These groups have worked to develop the best possible technical environment to continue improving diesel generator power plant performance, operation and maintenance.