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This study investigates the potential of controlling premixed charge compression ignition (PCCI) combustion strategies by varying fuel reactivity. In-cylinder fuel blending using port fuel injection of gasoline and early cycle, direct-injection of diesel fuel was used for combustion phasing control at a medium engine load of 9 bar net IMEP and was also found to be effective to prevent excessive rates of pressure rise. Parameters used in the experiments were guided from the KIVA-CHEMKIN code with a reduced primary reference fuel (PRF) mechanism including injection timings, fuel percentages, and intake valve closing (IVC) timings for dual-fuel PCCI combustion. The engine experiments were conducted with a conventional common rail injector (i.e., wide angle and large nozzle hole) and demonstrated control and versatility of dual-fuel PCCI combustion with the proper fuel blend, SOI and IVC timings.

The growing availability of different biofuels and synthetic fuels is leading to increased diversity of automotive fuels. Understanding how fuel properties affect combustion and how engine calibration strategies can compensate for variations in fuel composition is crucial for ensuring proper engine operation in this world of increased fuel diversity. This study looks at the ability to compensate for wide changes in cetane quality. Four different fuels with variations in cetane number, volatility and composition have been tested in a single cylinder engine and compared to diesel fuel. The selected operating conditions represent the entire engine map of a passenger car diesel engine. In part load the effects were investigated for conventional and premixed Diesel combustion. The results show that part load operation is especially relevant for the detection and compensation of varying fuel properties and that, depending on engine load, different control strategies have to be applied.

Homogenous Charge Compression Ignition (HCCI) combustion offers efficiency improvements compared to conventional gasoline engines. However, due to the nature of HCCI, traditional HCCI combustion can be realized only in a limited operating range. The HCCI operation at high load is limited by excessive combustion noise. In order to maximize the fuel economy benefits of HCCI its operating range needs to be extended to higher loads. In particular, one immediate benefit of an increased load range on the NEDC driving cycle is the avoidance of transitions between SI operation and HCCI operation. In this research a detailed investigation of the fundamental reasons for high combustion noise was performed. Spark-assisted HCCI combustion was found to be a key factor to reduce combustion noise at high load condition.

The influence of soy- and palm-based biofuels on the in-cylinder sources of unburned hydrocarbons (UHC) and carbon monoxide (CO) was investigated in an optically accessible research engine operating in a partially premixed, low-temperature combustion regime. The biofuels were blended with an emissions certification grade diesel fuel and the soy-based biofuel was also tested neat. Cylinder pressure and emissions of UHC, CO, soot, and NOx were obtained to characterize global fuel effects on combustion and emissions. Planar laser-induced fluorescence was used to capture the spatial distribution of fuel and partial oxidation products within the clearance and bowl volumes of the combustion chamber. In addition, late-cycle (30° and 50° aTDC) semi-quantitative CO distributions were measured above the piston within the clearance volume using a deep-UV LIF technique.

Two-poster rig plays a very important role in accelerated durability evaluation in a motorcycle industry, similar to what a four-poster rig does in a car industry. The rig simulates the exact road conditions in the vertical direction through tire coupling by applying feedback control on displacement. On account of its ability to simulate to the exact customer usage conditions, it reproduces the failures realistically as it happens on the field. However, as complete vehicle is required for testing on the rig, the testing happens mostly in the advanced stages of product development. Any failures beyond the concept stage have a huge impact on the development time and cost and the same should be avoided. Therefore, in this paper, a virtual testing methodology is proposed, based on which potential failures on the vehicles can be captured at the concept design stage itself. An ADAMS model of a motorcycle was created.

The typical approach for body load simulation during 7-Post testing has been to match body motion and forces for a known suspension setup condition, and then to maintain the applied body loads for subsequent tests with different setups. However, in order for the test to remain valid across a wide range of vehicle setups, the applied body loads may need to be varied to match the specific test car. A significant component of the body load comes from aerodynamic downforce, which can be calculated during a 7-Post test based on vehicle body position and previously recorded wind tunnel test data. This paper discusses a method to generalize the 7-Post inputs by updating the aerodynamic force content automatically during each test run. The paper begins by discussing validation of an active aerodynamic force control scheme on a MTS 320 7-Post road simulator with a NASCAR Sprint Cup vehicle.

Automotive manufacturers are facing continuously changing Global environment. Traditionally, these manufacturers relied on structural and general durability tests to validate vehicles. For these tests to remain representative of customer usage in a Global environment, the overall surface conditions of the Global road systems must be studied. Understanding and classifying these road systems conditions is an important step in dealing with vehicle durability in the Global environment. In this paper, an approach to mapping the world road systems into Established Roads (ER) and Developing Roads (DR), utilizing Statistical Discriminant Analysis (SDA), is presented. The classification of Global regions as DR and ER road systems can be effectively used to recommend appropriate development and validation tests for each road system. A few examples are presented to demonstrate how the ER vs.

Piston design is a challenging engineering problem which involves complex physics and requires satisfying multiple performance objectives. Uncertainty in piston operating conditions and variability in piston design variables are inevitable and must be accounted for. The piston assembly can be a major source of engine mechanical friction and cold start noise, if not designed properly. In this paper, an analytical piston model is used in a deterministic and probabilistic (reliability-based) multi-objective design optimization process to obtain an optimal piston design. The model predicts piston performance in terms of scuffing, friction and noise, In order to keep the computational cost low, efficient and accurate metamodels of the piston performance metrics are used. The Pareto set of all optimal solutions is calculated allowing the designer to choose the “best” solution according to trade-offs among the multiple objectives.

Combination of an NOx storage and reduction catalyst (NSRC, called also lean NOx trap, LNT) and a catalyst for the selective catalytic reduction of NOx by NH₃ (NH₃-SCR) offers a potential to significantly increase the efficiency of NSRC-based exhaust gas aftertreatment systems. Under most situations the SCR catalyst is able to adsorb the NH₃ peaks generated in the NSRC during the regeneration and utilize it for additional NOx reduction in the course of the consequent lean phase. This synergy becomes more important with the aged NSRC, where generally lower NOx conversions and higher NH₃ yields in wider range of operating temperatures are observed (in comparison with the fresh or de-greened NSRC). In this paper we present global kinetic models for the NSRC (Pt/Ba/Ce/gγ-Al₂O₃ catalyst type) and NH₃-SCR (Fe-ZSM5 catalyst type).

Although the design phase can account for a sizable amount of the resources consumed during the product realization process, the time and costs associated with the design process are often neglected when making design decisions. To investigate this issue, we define a process-centric decision model in which the design-phase consumption of resources, such as time and money, is explicitly modeled. While it is clear that the utility of a design is almost always directly impacted by the monetary costs of the design process, our decision model also accounts for the fact that the profit earned by a product depends strongly on its launch date. The decision model allows us thus to consider the trade-off between the time necessary for analysis and the improvement in product quality that results from the analysis. The decision model is sufficiently generic that almost any set of beliefs about the alternatives or analyses, as well as any utility-based preference structure can be modeled.

The use of early and late injection diesel Low Temperature Combustion (LTC) strategies in the low to mid load operating range are becoming increasingly popular options for production diesel engines to reduce oxides of nitrogen (NOx) and particulate matter (PM) emissions. Although opacity-based filter smoke number (FSN) PM measurements in these operating conditions have been reduced to near zero for many instruments (which are standard and very useful in most engine combustion research laboratories), significant changes can still be seen in the particle size and number measurements (such as a 2.5 - 4.5 fold variation in total particle number concentration, depending on engine operating condition). The current work presents particle size distribution measurements from early to late injection timing LTC, varying the start of injection (SOI) by three crank angle degrees (CAD) per data point, for two exhaust gas recirculation (EGR) rates, 45% and 50%.

Diesel engines operating in the low-temperature combustion (LTC) mode generally tend to produce very low levels of NOx and soot. However, the implementation of LTC is challenged by the higher cycle-to-cycle variation with heavy EGR operation and the narrower operating corridors. Small variations in the intake charge dilution can significantly increase the unburnt hydrocarbon and carbon monoxide emissions as well as escalate the consecutive cyclic fluctuations of the cylinder charge. This in turn adversely affects the robustness and efficiency of the LTC operation. However, Improvements in the promptness and accuracy of combustion control as well as tightened control on the intake oxygen concentration can enhance the robustness and efficiency of the LTC operation in diesel engines. In this work, a set of field programmable gate array (FPGA) modules were coded and interlaced to suffice on-the-fly combustion event modulations on a cycle-by-cycle basis.

The paper presents a study on the influence of increased rail pressure on the flow field of an injector nozzle at pressures of up to 3200 bar. Additionally the influence of nozzle conicity, HE-Rounding and nozzle-hole-diameter on the injector flow was investigated with CFD calculations. In these calculations the real behaviour of the nozzle movement was considered. The nozzles were tested on a special single cylinder research engine. The results showed high potential to fulfill EURO VI emission standards by raising the injection pressure and by optimizing the nozzle geometry, without exhaust aftertreatment measures.

Spray formation and break-up are crucial phenomena for mixture formation inside diesel engines, both for combustion control and pollutant formation. Since the emission restrictions have become more and more severe in the last years, many studies have been conducted in order to improve diesel injection. Numerical simulations have proven to be reliable in producing results in a faster and cheaper way than experimental measures. The recent great progresses in computer science, then, have allowed to reach great accuracy in the simulations. In this work, a novel methodology based on Boltzmanns Kinetic Theory is applied to diesel injection. Lattice Boltzmann BGK (LBGK) provides and alternative method for solving fluid-dynamic problems and allows even superior accuracy as compared to conventional CFD. The multiphase approach used in this paper to study spray formation and primary is based on the works by Shan and Chen and their successive modifications.

The potential of boosted HCCI for achieving high loads has been investigated for intake pressures (Piⁿ) from 100 kPa (naturally aspirated) to 325 kPa absolute. Experiments were conducted in a single-cylinder HCCI research engine (0.98 liters) equipped with a compression-ratio 14 piston at 1200 rpm. The intake charge was fully premixed well upstream of the intake, and the fuel was a research-grade (R+M)/2 = 87-octane gasoline with a composition typical of commercial gasolines. Beginning with Piⁿ = 100 kPa, the intake pressure was systematically increased in steps of 20 - 40 kPa, and for each Piⁿ, the fueling was incrementally increased up to the knock/stability limit, beyond which slight changes in combustion conditions can lead to strong knocking or misfire. A combination of reduced intake temperature and cooled EGR was used to compensate for the pressure-induced enhancement of autoignition and to provide sufficient combustion-phasing retard to control knock.

At temperatures below 1100 K, the oxidation of nitric oxide (NO) impacts the oxidation of hydrocarbons, causing a sensitization effect in fuel combustion. This effect can be important in engine operations, especially those involving high levels of exhaust-gas recirculation (EGR). Many researchers have observed this NO sensitization for the oxidation of hydrocarbons in HCCI engines as well as stirred reactors. They used several model-fuel components relevant to gasoline, such as n-heptane, iso-octane, and toluene. As found in stirred reactor experiments, NO tends to increase the extent of oxidation for high-octane fuel components, such as isooctane and toluene. However, for the low-octane component n-heptane, NO has an inhibiting effect on hydrocarbon oxidation, particularly at low temperatures corresponding to the negative temperature coefficient (NTC) region.

In diesel engines the optimization of engine-out emissions, combustion noise and fuel consumption requires the experimental investigation of the effects of different injection strategies as well as of a large number of engine operating variables, such as scheduling of pilot and after pulses, rail pressure, EGR rate and swirl level. Due to the high number of testing conditions involved full factorial approaches are not viable, whereas Design of Experiment techniques have demonstrated to be a valid methodology. However, the results obtained with such techniques require a subsequent critical analysis, so as to investigate the cause and effect relationships between the set of engine operating variables and the combustion process characteristics that affect pollutant formation, noise of combustion and engine efficiency.

Wide attention to fuel cell electric vehicles (FCEVs) comes from two huge issues currently the world is facing with: the concern of the petroleum reserves depletion due to consequent oil dependence and the earth global warming due in some extent to vehicle emissions. In this background, Hyundai, along with its sister company Kia, has been building the FCEVs and operating their test fleet with several tens of units at home and abroad. Since 2004, 32 passenger vehicles have been offered for the Department of Energy's controlled hydrogen fleet and infrastructure demonstration and validation project in the U.S. In the meantime, from 2006, 30 passenger vehicles as well as four buses, featuring the in-house developed fuel cell stack and its associated components, are currently under the domestic operation for the FCEV learning demonstration led by the Ministry of Knowledge and Economy.

The method of converting NOx with urea SCR is an effective solution for complying with the stringent NOx emission legislations of the future, particularly in the case of heavy duty diesel vehicles. In order to broaden the freedom of SCR catalyst design and volume design, a honeycomb structure formed with metal ion exchanged zeolite (NCH: New Concept Honeycomb) and for comparison a wash-coat type structure (conventional catalyst) were prepared. The possible range of catalyst volume reduction in NCH was investigated by comparative measurement of NH₃ adsorption distribution, consumption behavior of adsorbed NH₃ within the structures, and of space velocity and NO₂/NOx dependence of NOx conversion efficiency. In addition, from NEDC evaluation in an engine bench, it was found that combining urea injection logic suitable for NCH results in equal or higher NOx conversion efficiency and NH₃ slip characteristics with only 1/2 the volume of conventional catalyst structure.

Ammonia/urea-SCR is a mature technology, applied worldwide for the control of NOx emissions in combustion exhausts from thermal power plants, cogeneration units, incinerators and stationary diesel engines and more recently also from mobile sources. However a greater DeNOx activity at low temperatures is desired in order to meet more and more restrictive legislations. In this paper we report transient and steady state data collected over commercial Fe-ZSM-5 and V₂O₅-WO₃/TiO₂ catalysts showing high NOx reduction efficiencies in the 200 - 350°C T-range when NO and ammonia react with nitrates, e.g., in the form of an aqueous solution of ammonium nitrate. Under such conditions a new reaction occurs, the so-called "Enhanced SCR" reaction, 2 NH₃ + 2 NO + NH₄NO₃ → 3 N₂ + 5 H₂O.