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The study measured Mass Air Flow, (MAF), Manifold Absolute Pressure, (MAP), and emissions of NO and soot during fourteen transients of speed and load, representative of the Extra Urban Drive Cycle (EUDC). The tests were conducted on a typical passenger car/light-duty truck powertrain (a turbocharged common-rail diesel engine, of in-line 4-cylinder configuration). The objective was to compare NO and soot with corresponding steady-state emission results and propose an engine measurement methodology that will potentially quantify deviation (i.e. deterioration with respect to steady state optimum) in emissions of NO and soot during transients. Comparison between steady state, quasi-steady-states (defined later in the paper) and transients indicated that discrete quasi-steady-state engine operation, can be used for accurate prediction of transient emissions of NO and soot.

The global use of biodiesel fuel blends derived from fatty acid methyl esters (FAME) is increasing; driven by legislation derived from political, economic and environmental factors. The presence of FAME biodiesel changes the operating environment of the engine and after treatment devices, affecting the performance characteristics and requirements of the lubricant. As part of a wider research project into the impact of biologically-sourced fuels on crankcase lubricant performance, this paper documents the impact of biodiesel on corrosion-related performance. The effect of FAME biodiesel on lubricant corrosion control and the differences in performance due to FAME source are described. Mechanistic studies into the corrosive nature of FAME are reported. Novel lubricant technologies tailored to control the negative impact of FAME in the crankcase are demonstrated.

Organic acid degradation products and other anions in engine oil were speciated by capillary electrophoresis (CE) and liquid chromatography-mass spectrometry (LCMS) with electrospray ionization. The sample preparation procedure involved selectively extracting the acids and other water soluble salts into 0.05M aqueous potassium hydroxide. Samples of engine-aged mineral oil and synthetic engine oil contained formic acid, acetic acid, and complex mixtures of fatty acid degradation products. CE analysis of formic acid, acetic acid and selected fatty acids is proposed as a new chemical analysis method for evaluating the condition of engine oil and for studying the effects of high temperature-high load (HTHL) oxidation. Because the overall pattern of CE peaks in the electropherogram changes with oil age or condition, CE-fingerprint (i.e., pattern recognition) techniques may also be useful for evaluating an aged oil's condition or remaining service life.

This paper deals with experimental study of in-cylinder tumble flows in a single-cylinder, four-stroke, two-valve internal combustion engine using a pentroof-offset-bowl piston under non-reacting conditions with four intake manifold orientations at an engine speed of 1000 rev/min., during suction and compression strokes using particle image velocimetry. Two-dimensional in-cylinder tumble flow measurements and analysis are carried out in combustion space on a vertical plane passing through cylinder axis. Ensemble average velocity vectors are used to analyze the tumble flows. Tumble ratio (TR) and average turbulent kinetic energy (TKE) are evaluated and used to characterize the tumble flows. From analysis of results, it is found that at end of compression stroke, 90° intake manifold orientation shows an improvement in TR and TKE compared other intake manifold orientations considered.

The authors have developed a measurement technique using a new digital telemeter which measures the piston secondary motion as ensuring high accuracy while under the operation. We applied this new digital telemeter to several measurements and analysis on the piston secondary motion that can cause piston noises, and here are some of the results from our measurement. We have confirmed that these piston motions vary by only several tenths of millimeter changes of the piston specifications such as the piston-pin offset and the center of gravity of the piston. As in other cases, we have found that a mere change of pressure in the crankcase or the amount of lubricating oil supplied on the cylinder bore varies the piston motion that may give effect on the piston noises.

This paper presents the comparison of two different approaches for crankcase structural analysis. The first approach is a conventional quasi-static simulation, which will not be detailed in this work and the second approach involves determining the dynamic loading generated by the crankshaft torsional, flexural and axial vibrations on the crankcase. The accuracy of this approach consists in the development of a robust mathematical model that can couple the dynamic characteristics of the crankshaft and the crankcase, representing realistically the interaction between both components. The methodology to evaluate these dynamic responses is referred to as hybrid simulation, which consists of the solution of the dynamics of an E-MBS (Elastic Multi Body System) coupled with consecutive FEA (Finite Element Analysis).

Regarding the strongly growing two-wheeler market fuel economy, price and emission legislations are in focus of current development work. Fuel economy as well as emissions can be improved by introduction of engine management systems (EMS). In order to provide the benefits of an EMS for low cost motorcycles, efforts are being made at BOSCH to reduce the costs of a port fuel injection (PFI) system. The present paper describes a method of how to reduce the number of sensors of a PFI system by the use of sophisticated software functions based on high-resolution engine speed evaluation. In order to improve the performance of a system working without a MAP-sensor (manifold air pressure sensor) an air charge feature (ACFn) based on engine speed is introduced. It is shown by an experiment that ACFn allows to detect and adapt changes in manifold air pressure. Cross-influences on ACFn are analyzed by simulations and engine test bench measurements.

This study deals with reduced-order modeling of intake air dynamics in single-cylinder four-stroke naturally-aspirated spark-ignited engines without surge tanks. It provides an approximate calculation method for embedded micro computers to estimate intake manifold pressures in real time. The calculation method is also applicable to multi-cylinder engines with individual throttle bodies since the engines can be equated with parallelization of the single-cylinder engines. In this paper, we illustrate the intake air dynamics, describe a method to estimate the intake manifold pressures, and show experimental results of the method.

The rotary engine provides high power density compared to piston engine, but one of its downside is higher oil consumption. A model of the oil seals is developed to calculate internal oil consumption (oil leakage from the crankcase through the oil seals) as a function of engine geometry and operating conditions. The deformation of the oil seals trying to conform to housing distortion is calculated to balance spring force, O-ring and groove friction, and asperity contact and hydrodynamic pressure at the interface. A control volume approach is used to track the oil over a cycle on the seals, the rotor and the housing as the seals are moving following the eccentric rotation of the rotor. The dominant cause of internal oil consumption is the non-conformability of the oil seals to the housing distortion generating net outward scraping, particularly next to the intake and exhaust port where the housing distortion valleys are deep and narrow.

Novel water management and reactant distribution strategies are critical to next generation polymer electrolyte membrane fuel cell systems (PEMFCs). Improving these strategies in PEMFCs leads to higher power density and reduced stack size for vehicle applications, which reduces weight and improves the price competitiveness of these systems. Interdigitated flow fields induce convective transport (cross flow) through the porous GDL between adjacent channels and are superior at water removal beneath land areas, which can lead to higher cell performance. However, the head loss due to flow, among other factors, may cause cross flow maldistribution of reactants down the channel. Such maldistribution may lead to areas of low or areas of excess cross flow. This, in turn, can cause areas of low oxygen concentration and water build up, and therefore higher pressure losses and uneven membrane hydration, all of which reduce overall cell performance.

Reliability has always been an important aspect in the assessment of industrial products and/or equipments. Good product design is of course essential for products with high reliability. However, no matter how good the product design is, products deteriorate over time since they are operating under certain stress or load in the real environment, often involving randomness. Maintenance has, thus, been introduced as an efficient way to assure a satisfactory level of reliability during the useful life of a physical asset. The earliest maintenance technique is basically breakdown maintenance (also called unplanned maintenance, or run-to-failure maintenance), which takes place only at breakdowns. A later maintenance technique is time-based preventive maintenance (also called planned maintenance), which sets a periodic interval to perform preventive maintenance regardless of the health status of a physical asset. The vehicle component is judged to be safe depending on its reliability.

The Torque from an engine is a very critical parameter which controls the drivability of the vehicle, better torque availability at Partially Open Throttle (POT) condition improves drivability at city driving condition and better torque at Wide Open Throttle (WOT) condition improves cruising at highway driving condition, conventionally engine produces better torque at one particular operating condition leaving poor drivability at others. The Torque characteristics of an engine depends upon the volumetric efficiency of the engine. The volumetric efficiency of a naturally aspirated engine can be improved by tuning the intake manifold. With an overall improvement in volumetric efficiency throughout the engine operating conditions better torque curve can be achieved, which facilitates improved drivability.

The present paper describes a CAE analysis approach to evaluate the design of exhaust manifold of a turbo charged gasoline engine. It allows design engineers to identify structural weakness at the early stage or to find the root cause of exhaust manifold failures. A transient none-linear finite element method is used to calculate the plastic deformation and thermal mechanical behaviors of the exhaust manifold assembly during thermal shock cycles, which include rated speed full load, rated speed motored and idle speed conditions. A transient heat transfer simulation is performed to provide thermal boundary conditions for the nonlinear stress/strain analysis. The finite element model includes a part of cylinder head, exhaust manifold, gaskets, turbo charger housing, catalytic converter, brackets, bolts and nuts. The results show that plastic deformation is the main cause of manifold cracking and the manifold flange distortion causes the exhaust leakage.

The in-cylinder tumble intensity of GDI engine is crucial to combustion stability and thermal efficiency, required to be different for the different operation conditions. A new variable tumble system (VTS) applied to GDI engine was introduced to meet tumble ratio requirements in various situations. The transient gas exchange of four combustion systems all were investigated during both intake and compression strokes based on CFD simulation, namely (1) Case 1-Intake port B (with flap valve)/Spherical piston crown; (2) Case 2-Intake port B (without flap valve)/Spherical piston crown; (3) Case 3- Intake port A/Spherical piston crown; (4) Case 4-Intake port A/Dented piston crown. The simulated results of dynamic tumble ratio showed that during the whole intake process the dynamic tumble ratio of Case1 was obviously higher than other Cases with the same boundary conditions, and the maximum value was about 5∼6 times higher.

One of the most significant current discussions worldwide is the anthropogenic climate change accompanying fossil fuel consumption. Sustainable development in all fields of combustion engines is required with the principal objective to enhance efficiency. This certainly concerns the field of hand-held power tools as well. Today, two-stroke SI engines equipped with a carburetor are the most widely used propulsion technology in hand-held power tools like chain saws and grass trimmers. To date, research tended to focus on two-stroke engines with rich mixture setting. In this paper the advantages and challenges of leaner and/or lean operation are discussed. Experimental investigations regarding the influence of equivalence ratio on emissions, fuel consumption and power have been performed. Accompanying 3D-CFD simulations support the experiments in order to gain insight into these complex processes. The investigations concentrate on two different mixture formation processes, i.e.

Cost reduction of engine management systems (EMS) for two-wheeler applications is the key to utilize their potentials compared to carburetor bikes regarding emissions, fuel economy and system robustness. In order to reduce the costs of a system with port fuel injection (PFI) Bosch is developing an EMS without a manifold air pressure (MAP) sensor. The pressure sensor is usually used to compensate for different influences on the air mass, which cannot be detected via the throttle position sensor (TPS) and mean engine speed. Such influences are different leakage rates of the throttle body and changing ambient conditions like air pressure. Bosch has shown in the past that a virtual sensor relying on model based evaluation of engine speed can be used for a detection of leakage air mass in idling to improve the pre-control of the air-fuel ratio. This provides a functionality which so far was only possible with an intake pressure sensor.

Recently, a potentiality of Dedicated EGR (D-EGR) concept SI engine has been studied. This concept engine had four cylinders and operated with exhaust gas supplied from the single cylinder to the intake manifold. Compared with conventional SI engines, it was able to increase thermal efficiency and decrease CO, HC, and NOx emission by the high D-EGR ratio 0.25. In this study, numerical analysis of a SI engine with D-EGR system with various D-EGR ratios was conducted for detailed understanding the potentiality of this concept in terms of thermal efficiency and NOx emission. #1 cylinder of assumed engine was used as D-EGR cylinder that equivalence ratio varied from 0.6 to 3.4. Entire exhaust gas from #1 cylinder was recirculated to the other cylinders. The other cylinders run with this exhaust gas and new premixed air and fuel with various equivalence ratios from 0.6-1.0.

An afterburner-assisted turbocharged single-cylinder 425 cc two-stroke SI-engine is described in this simulation study. This engine is intended as a Backup Range Extender (REX) application for heavy-duty battery electric vehicles (BEV) when external electric charging is unavailable. The 425 cc engine is an upscaled version of a 125 cc port-injected engine [26] which demonstrated that the selected technology could provide a specific power level of 400 kW/L and the desired 150 kW in a heavy duty BEV application. The 425 cc single cylinder two-stroke engine is an existing engine as one half of a 850 cc snowmobile engine. This simulation study includes upscaling of the swept volume, impact on engine speed and gas exchange properties. In the same way as for the 125cc engine [26], the exhaust gases reaches the turbine through a tuned exhaust pipe and an afterburner or oxidation catalyst.

Methane supply in diesel engines operating in dual fuel mode has demonstrated to be effective for the reduction of particulate matter and nitric oxides emissions from this type of engine. In particular, methane is injected into the intake manifold to form a premixed charge with air, while a reduced amount of diesel oil is still directly injected to ignite the mixture inside the cylinder. As a matter of fact, the liquid fuel burns following the usual diffusive combustion, so activating the gaseous fuel oxidation in a premixed flame. Clearly, the whole combustion process appears to be more complex to be described in a CFD simulation, mainly because it is not always possible to select in the 3-dimensional codes a different combustion model for each fuel and, also, because other issues arise from the interaction of the two fuels.

As part of transformation from BS4 to BS6 automobile emission standard in India, engine manufactures are focusing on continuous development of emission control technologies and suitable strategies. Exhaust tail pipe emission and Crankcase emission are added together to meet the regulation acceptable limit. The crankcase emissions contribute substantially to the total Particulate Matter (PM) emitted from an engine. Hence there is a need of design and development of suitable Crankcase ventilation system. This paper presents investigation of high PM contributed from Open Crankcase ventilation (OCV) system in Diesel engine and experiment based solutions.