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Consumers design different PHEVs than expert analysts assume. Experts almost uniformly assume PHEVs that offer true all-electric driving for 10 to 60 miles; consumers are more likely to design PHEVs that do not offer true all-electric driving and have short ranges over which they use grid-electricity. Thus consumers? PHEV designs are less expensive. These consumer PHEV designs do, or don?t, produce lower GHG emissions than experts? PHEVs over the next ten years. The devil is in the details, i.e., which powerplant emissions to assign to new electricity demand: marginal or average. If (based on marginal powerplant emissions) it makes almost no difference whether we sell consumer-designed or expert-assumed PHEVs over the next ten years, yet as the grid continues to de-carbonize all-electric PHEV designs emerge as clearly the better option, there is a trajectory we could be on from blended, ?short range? PHEVs to all-electric ?long range? PHEVs.

For (benchmark) tests it is not only useful to study the acoustic performance of the whole vehicle, but also to assess separate components such as the engine. Reflections inside the engine bay bias the acoustic radiation estimated with sound pressure based solutions. Consequently, most current methods require dismounting the engine from the car and installing it in an anechoic room to measure the sound emitted. However, this process is laborious and hard to perform. In this paper, two particle velocity based methods are proposed to characterize the sound radiated from an engine while it is still installed in the car. Particle velocity sensors are much less affected by reflections than sound pressure microphones when the measurements are performed near a radiating surface due to the particle velocity's vector nature, intrinsic dependency upon surface displacement and directivity of the sensor. Therefore, the engine does not have to be disassembled, which saves time and money.

Since the amount of emitted CO2 is directly related to car fuel economy, attention is being drawn to DISI (Direct-Injection Spark-Ignition) engines, which have better fuel economy than conventional gasoline engines. However, it has been a problem that the rich air-fuel mixtures associated with fuel films during cold starts due to spray impingement produce particulate matter (PM). In predicting soot formation, it is important to predict the mixture field precisely. Thus, accurate spray and film models are a prerequisite of the soot model. The previous models were well matched with low-speed collision conditions, such as those of diesel engines, which have a relatively high ambient pressure and long traveling distances. Droplets colliding at low velocities have an order of magnitude of kinetic energy similar to that of the sum of the surface tension energy and the critical energy at which the splash occurs.

In the brake system, unevenly distributed disc-pad contact pressure not only leads to a falling-off in braking feeling due to uneven wear of brake pads, but also a main cause of system instability which leads to squeal noise. For this reason there have been several attempts to measure contact pressure distribution. However, only static pressure distribution has been measured in order to estimate the actual pressure distribution. In this study a new test method is designed to quantitatively measure dynamic contact pressure distribution between disc and pad in vehicle testing. The characteristics of dynamic contact pressure distribution are analyzed for various driving conditions and pad shape. Based on those results, CAE model was updated and found to be better in detecting propensity of brake squeal.

CO2 emission is more serious in recent years and automobile manufacturers are interested in developing technologies to reduce CO2 emissions. Among various environmental-technologies, the use of solar roof as an electric energy source has been studied extensively. For example, in order to reduce the cabin ambient temperature, automotive manufacturers offer the option of mounting a solar cell on the roof of the vehicle [1]. In this paper, we introduce the semi-transparent solar cell mounted on a curved roof glass and we propose a solar energy management system to efficiently integrate the electricity generated from the solar roof into internal combustion engine (ICE) vehicles. In order to achieve a high efficiency solar system in different driving, we improve the usable power other than peak power of solar roof. Peak power or rated power is measured power (W) in standard test condition (@ 25°C, light intensity of 1000W/m2(=1Sun)).

Fuel sloshing noise is involved with flow motion inside fuel tanks as well as structural characteristics of vehicles. Therefore it is necessary to introduce Fluid-Structure Interaction (FSI) analysis to predict sloshing noise phenomena more accurately. Purposes of this paper are to verify the reliability of the FSI method and suggest new CAE analysis processes to predict fuel sloshing noise. The vibration of floor panels induced by sloshing impact is evaluated through FSI analysis. A series of tests is carried out to validate simulation results. The numerical optimization of parameters is also carried out to reduce computation time. In addition, effects of sloshing noise factors are discussed based on simulation and test results. Lastly, a method to predict fuel sloshing noise by exerting sloshing load on a vehicle is suggested.

As fuel injection strategies in spark-ignition (SI) engines have been diversified, inhomogeneous mixing of the fuel-air mixture can occur to varying extents during mixture preparation. In this study, we analyzed the effect of inhomogeneous mixing on the knocking characteristics of iso-octane and air mixture under a standardized fuel testing condition for research octane number (RON), based on ASTM D2699. For this purpose, we assumed that both lean spots and rich spots existed in unburned gas during compression stroke and flame propagation and calculated the thermodynamic state of the spots by using an in-house multi-zone, zero-dimensional SI engine model. Then, the ignition delay was measured over the derived thermodynamic profiles by using rapid compression machine (RCM), and we calculated ξ, the ratio of sound speed to auto-ignition propagation speed, based on Zel’dovich and Bradley’s ξ − ε theory to estimate knock intensity.

A combined experimental and computational study of 3-D unsteady compressible flow in exhaust manifold and CCC system was performed to understand the flow characteristics and to improve the flow distribution of pulsating exhaust gases within monolith. An experimental study was carried out to measure the velocity distribution in production exhaust manifold and CCC under engine operating conditions using LDV (Laser Doppler Velocimetry) system. Velocity characteristics were measured at planes 25 mm away from the front surface of first monolith and between two monolithic bricks. To provide boundary conditions for the computational study, velocity fields according to crank angle were also measured at the entrance of exhaust manifold. The comparisons of exhaust gas flow patterns in the junction and mixing pipe between experimental and computational results were made.

In this study, compositions, size distributions and activation energy in oxidation of diesel PM were investigated. Benzene (C6H6) was mixed to diesel fuel as a promoter of PM formation, and further, ferrocene (Fe(C5H5)2) was added as a promoter for oxidation processes during in-cylinder combustion and after-treatment. The effect of those additions on the PM characteristics was discussed on the basis of measured results such as SOF and dry-soot ratio in PM, primary and aggregate particle size distributions of PM, activation energy of PM oxidation, and PM components with elemental analysis. As a result, it was shown that ferrocene had special effect on the PM size distribution and the activation energy.

Modeling of unburned hydrocarbon oxidation in an SI engine was performed in engine condition using modified one-step oxidation model. The new one-step equation was developed by modifying the Arrhenius reaction rate coefficients of the conventional one-step model. The modified model was well matched with the results of detailed chemical reaction mechanism in terms of 90 % oxidation time of the fuel. In this modification, the effect of pressure and intermediate species in the burnt gas on the oxidation rate investigated and included in developed one-step model. The effect of pressure was also investigated and included as an additional multiplying factor in the reaction equation. To simulate the oxidation process of piston crevice hydrocarbons, a computational mesh was constructed with fine mesh density at the piston crevice region and the number of cell layers in cylinder was controlled according to the motion of piston.

Numerous machine elements are operated in mixed lubrication regime where is governed by a combination of boundary and fluid film effects. The direct contact between two surfaces reduces a machines life by increasing local pressure. In order to estimate machine's life exactly, the effect of asperity contact should be considered in the lubrication model. In this study, new 3-dimensional partial elasto-hydrodynamic lubrication (PEHL) algorithm is developed. The algorithm contains the procedures to find out solid contact regions within the lubricated regime and to calculate both the pressure by fluid film and the contact pressure between the asperities of the solids. Using the algorithm, we conducted the PEHL analysis for the contact between the rotating shaft and the inside of pinion gear. To investigate the effect of surface topology two different surfaces with sinusoidal profile are used. Both film thickness and pressure are calculated successfully through the PEHL algorithm.

Adopting the Spray-guided Gasoline Direct Injection (SGDI) concept, a new multi-cylinder engine has designed. The engine has piezo injectors at the central position of its combustion chamber, while sparkplugs are also at the center. The sparkplug location is designed so that the spark location is at the outer boundary of the fuel spray where the appropriate air-fuel mixture is formed. A few important operating parameters are chosen to investigate their effects on the combustion stability and fuel consumption. The final experimental results show a good potential of the SGDI engine; the fuel consumption rate was much less than that of the base Multi Port Injection (MPI) engine at various engine operating conditions.

As the current and future emission regulations become stringent, the research on exhaust manifold with CCC (Close Coupled Catalyst) has been the interesting and remarkable subject. To design of exhaust manifold with CCC is a difficult task due to the complexity of the flow distribution caused by the pulsating flows that are emitted at the exhaust ports. This study is concerned with the theoretical and experimental approach to improve catalyst flow uniformity through the basic understanding of exhaust flow characteristics. Computational and experimental approach to the flow for exhaust manifold of conventional cast type, stainless steel bending type with 900 cell CCC system in a 4-cylinder gasoline engine was performed to investigate the flow distribution of exhaust gases.

Diesel engines are the most commonly used power plant of freight and public transportations in the world. Also, the newly developed injection system, Common Rail system, increases the demands for both light and heavy duty diesel vehicles. On the other hand, stringent emission regulations are being proposed with growing concern on NOx and PM emissions from diesel engines. Future emission regulations require advanced emission control technologies, such as EGR and SCR. Exhaust gas recirculation (EGR) is a commonly used technique to reduce NOx emission. In this paper, a model-based investigation was conducted to compare the effect of high pressure loop (HPL) EGR and low pressure loop (LPL) EGR system on NOx level and BSFC of a heavy-duty diesel engine. A WAVE model was created to simulate EURO 3 engine and each component of the engine was modeled using CATIA and WaveMesher.

Characteristics of syngas combustion at various reforming ratios were studied numerically. The syngas was formed by the partial oxidation of methane to mainly hydrogen and carbon monoxide and cooled to ambient temperature. Stiochiometric and lean premixed flames of the mixtures of methane and the syngas were compared at the atmospheric temperature and pressure conditions. The adiabatic flame temperature decreased with the reforming ratio. The laminar burning velocity, however, increased with the reforming ratio. For stretched flames in a counterflow, the high temperature region was broadened with the reforming ratio. The maximum flame temperature decreased with the reforming ratio for the stoichiometric case, but increased for the lean case except for the region of very low stretch rate. The extinction stretch rate increased with the reforming ratio, implying that the syngas assisted flame is more resistance to turbulence level.

The Diesel Particulate Filter (DPF) modeling has been used to predict the pressure drop, deposited soot mass and regeneration of DPF. But the prediction of DPF behavior requires the experimental data in which the most important parameter is hydrodynamic resistance factor. In this research, it was obtained as a function of particle's approach velocity. Also, the relations between the pressure drop and deposited soot mass were obtained experimentally. In order to investigate the characteristics of soot loading and oxidation behavior within DPF, a partial flow system was designed which can be used to measure important parameters at the same temperature and flow rate with those of the single channel DPF.

Characteristics of soot oxidation were investigated with a carbon black (Printex-U). A flow reactor system which can simulate the condition of diesel particulate filter and diesel exhaust gas (1 bar, O2 0 ∼ 10%, NO2 200 ∼ 900ppm) was designed and used with the temperature programmed oxidation (TPO) and constant temperature oxidation (CTO) techniques. The temperature increase rate was 5°C/min for TPO experiments. From the experiments, the apparent activation energy for carbon oxidation with nitrogen dioxide was determined as 60 ± 3 kJ/mol with the first order of carbon in the range of 10∼90% oxidation and the temperature range of 250∼500°C. This value was exceedingly lower than the activation energy of oxygen oxidation which was 177 ± 1 kJ/mol. When oxygen exists with nitrogen dioxide, the reaction rate increased with the concentration of oxygen. Its rate of increase was faster for low oxygen concentration and slower for high concentration.

Today's diesel PM reduction systems are mainly based on catalyzed particulate filter(CPF) systems. However, most of their reaction kinetics remain unresolved. Among others, the soot oxidation rate over catalyst is particularly important in the evaluation of the performance of the catalysts and the efficient control of CPF regeneration. This study, therefore, investigated the oxidation rate of carbon black (Printex-U) over various Pt supported catalysts using a flow reactor setup simulating diesel exhaust conditions. Compared to non-catalyzed soot oxidation, the oxidation rate of carbon black over Pt catalysts was to an extent shifted towards low temperatures. This activity enhancement of soot oxidation over a catalyst can be attributed principally to NO to NO2 conversion because NO2 oxidizes soot with much lower activation energy (Ea=60kJ/mol) than O2 (Ea=177kJ/mol).

Shudder vibration of a hydraulic power steering system during parking maneuver was studied with numerical and experimental methods. To quantify vibration performance of the system and recognize important stimuli for drivers, a shudder metric was derived by correlation between objective measurements and subjective ratings. A CAE model for steering wheel vibration analysis was developed and compared with measured data. In order to describe steering input dependency of shudder, a new dynamic friction modeling method, in which the magnitude of effective damping is determined by average velocity, was proposed. The developed model was validated using the measured steering wheel acceleration and the pressure change at inlet of the steering gear box. It was shown that the developed model successfully describes major modes by comparing the calculated FRF of the hydraulic system with measured one from the hydraulic excitation test.

As the use of diesel engines increases in the transportation industry and emission regulations tighten, the implementation of diesel particulate filter systems has expanded. There are many challenges associated with the design and development of these systems. Some of the key robustness parameters include regeneration, efficiency, fuel penalty, engine performance, and durability. One component of durability in a diesel particulate filter (DPF) system is the filter's ability to resist ring-off-cracking (ROC). ROC is described as a crack caused primarily by thermal gradients, differentials, and the resulting stresses within the DPF that exceed its internal strength. These cracks usually run perpendicular to the substrate flow axis and typically result in the breaking of the substrate into separate halves.