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This study reanalyzes the data from a recent experimental report from the University of Utah investigating the effect on driving performance of auditory-vocal secondary tasks (such as cell phone and passenger conversations, speech-to-text, and a complex artificial cognitive task). The current objective is to estimate the relative risk of crashes associated with such auditory-vocal tasks. Contrary to the Utah study's assumption of an increase in crash risk from the attentional effects of cognitive load, a deeper analysis of the Utah data shows that driver self-regulation provides an effective countermeasure that offsets possible increases in crash risk. For example, drivers self-regulated their following distances to compensate for the slight increases in brake response time while performing auditory-vocal tasks. This new finding is supported by naturalistic driving data showing that cell phone conversation does not increase crash risk above that of normal baseline driving.

The objective of this research is to investigate the effect of the blast load on the vehicle and occupant and identify the sensitivity of the vehicle parameters to the blast load, therefore figure out the design solution to protect the vehicle and occupant. CAE explicit commercial code, LSDYNA, is applied in this research with adopting CONWEP method for the blast load. The LSDYNA 95th percentile Hybrid III dummy model is used for occupant simulation. Seat, seat belt, and underbody and underbody armor are interested areas in the design to meet the survivability and weight target. The results show the protection can be effectively achieved through employing the new design method in three areas mentioned above.

This paper presents the results of an experimental investigation on a single cylinder engine to validate a two-component JP-8 surrogate. The two-component surrogate was chosen based on a previous investigation where the key properties, such as DCN, volatility, density, and lower heating value, of the surrogate were matched with those of the target JP-8. The matching of the auto-ignition, combustion, and emission characteristics of the surrogate with JP-8 was investigated in an actual diesel engine environment. The engine tests for the validation of the surrogate were conducted at an engine speed of 1500 rpm, a load of 3 bar, and different injection timings. The results for the cylinder gas pressure, ignition delay period, rate of heat release, and the CO, HC, and NOx emissions showed a good match between the surrogate and the target JP-8. However, the engine-out particulate matter for the surrogate was lower than that for the JP-8 at all tested conditions.

An experimental study was carried out to characterize the exhaust flow structure inside the closed-coupled catalytic converter, which is installed on a firing four-cylinder 12-valve passenger car gasoline engine. Simultaneous velocity and pressure measurements were taken using cycle-resolved Laser Doppler anemometer (LDA) technique and pressure transducer. A small fraction of titanium (IV) iso-propoxide was dissolved in gasoline to generate titanium dioxide during combustion as seeding particles for the LDA measurements. It was found that the velocity is highly fluctuating due to the pulsating nature of the engine exhaust flow, which strongly depends on the engine operating conditions and the measuring locations. The pressure oscillation is correlated with the transient exhaust flow characteristics. The main exhaust flow event from each cylinder can only be observed at the certain region in front of the monolith brick.

A three-dimensional finite element model of a human neck has been developed in an effort to study the mechanics of cervical spine while subjected to impacts. The neck geometry was obtained from MRI scans of a 50th percentile male volunteer. This model, consisting of the vertebrae from C1 through T1 including the intervertebral discs and posterior elements, was constructed primarily of 8-node brick elements. The vertebrae were modeled using linear elastic-plastic materials, while the intervertebral discs were modeled using linear viscoelastic materials. Sliding interfaces were defined to simulate the motion of synovial facet joints. Anterior and posterior longitudinal ligaments, facet joint capsular ligaments, alar ligaments, transverse ligaments, and anterior and posterior atlanto-occipital membranes were modeled as nonlinear bar elements or as tension-only membrane elements. A previously developed head and brain model was also incorporated.

The effect of biodiesel on the Particulate emissions is gaining significant attention particularly with the drive for the use of alternative fuels. The particulate matter (PM), especially having a diameter less than 50 nm called the Nanoparticles or Nucleation mode particles (NMPs), has been raising concerns about its effect on human health. To better understand the effect of biodiesel and its blends on particulate emissions, steady state tests were conducted on a small-bore single-cylinder high-speed direct-injection research diesel engine. The engine was fueled with Ultra-Low Sulfur Diesel (ULSD or B-00), a blend of 20% soy-derived biodiesel and 80% ULSD on volumetric basis (B-20), B-40, B-60, B-80 and 100% soy-derived biodiesel (B-100), equipped with a common rail injection system, EGR and swirl control systems at a load of 5 bar IMEP and constant engine speed of 1500 rpm.

The feasibility of using ultra low sulfur diesel (ULSD), synthetic paraffinic kerosene (S-8), military grade jet fuel (JP-8) and commercial B20 blend (20% v biodiesel in ULSD) in a power generator equipped with a compression ignition (CI) engine was investigated according to the MIL-STD-705C military specifications for engine-driven generator sets. Several properties of these fuels such as cetane number, lubricity, viscosity, cold flow properties, heat of combustion, distillation temperatures, and flash point, were evaluated. All fuels were tested for 240 hours at a stationary load of 30 kW (60% of full load) with no alteration to the engine calibrations. The brake specific fuel consumption (BSFC), brake thermal efficiency (BTE), frequency, and power of the generator using S-8, JP-8 and B20 were compared with the baseline fuel ULSD.

Because of their robustness and cost performance, multi-hole gasoline injectors are being adopted as the direct injection (DI) fuel injector of choice as vehicle manufacturers look for ways to reduce fuel consumption without sacrificing power and emission performance. To realize the full benefits of direct injection, the resulting spray needs to be well targeted, atomized, and appropriately mixed with charge air for the desirable fuel vapor concentration distributions in the combustion chamber. Ethanol and ethanol-gasoline blends synergistically improve the turbo-charged DI gasoline performance, especially in down-sized, down-sped and variable-valve-train engine architecture. This paper presents the spray imaging results from two multi-hole DI gasoline injectors with different design, fueled with pure ethanol (E100) or gasoline (E0), under homogeneous and stratified-charge conditions that represent typical engine operating points.

Lower extremity injuries in frontal automotive crashes usually occur with footwell intrusion where both the knee and foot are constrained. In order to identify factors associated with tibial shaft injury, a series of numerical simulations were conducted using a finite element model of the whole human body. These simulations demonstrated that tibial mid-shaft injuries in frontal crashes could be caused by an abrupt change in velocity and a high rate of footwell intrusion.

Analysis of flow field and charge distribution in a gasoline direct-injection (GDI) engine is performed by a modified version of the KIVA code. A particle-based spray model is proposed to simulate a swirl-type hollow-cone spray in a GDI engine. Spray droplets are assumed to be fully atomized and introduced at the sheet breakup locations as determined by experimental correlations and energy conservation. The effects of the fuel injection parameters such as spray cone angle and ambient pressure are examined for different injectors and injection conditions. Results show reasonable agreement with the measurements for penetration, dispersion, global shape, droplet velocity and size distribution by Phase Doppler Particle Anemometry(PDPA) in a constant-volume chamber. The test engine is a 4-stroke 4-valve optically accessible single-cylinder engine with a pent-roof head and tumble ports.

In view of the new regulations for diesel engine emissions, EGR is used to reduce the NOx emissions. Diluting the charge with EGR affects the autoignition, combustion as well as the regulated and unregulated emissions of diesel engines, under different operating conditions. This paper presents the results of an investigation on the effect of EGR on the global activation energy and order of the autoignition reactions, premixed and mixing-controlled combustion fractions, the regulated (unburned hydrocarbons, NOx, CO and particulates), aldehydes, CO2 and HC speciation. The experiments were conducted on two different direct injection, four-stroke-cycle, single-cylinder diesel engines over a wide range of operating conditions and EGR ratios.

The Ultrasonic Collision Avoidance System is designed to eliminate collisions when cars, trucks, and other vehicles are backing up. Many backup collisions result when objects are not in view or when a driver underestimates the distance to the object. The Ultrasonic Proximity System warns the driver of objects in the path and displays the distance to the object. The distance to an object is represented by a 10 segment light emitting diode (LED) bar graph. If all LED's are off, the object is more than 10 feet away. The first LED will illuminate at approximately 10 feet, and as the vehicle moves closer to the obstruction more LED's illuminate, about 1 LED per foot. If the object is closer than 1′-6″, the last LED will illuminate and an audible alarm will sound.

Heidelberg-type side impact sled tests were conducted using SID side impact dummies. These tests were run under similar conditions to a series of cadaveric sled tests funded by the Centers for Disease Control in the same lab. Tests included 6.7 and 9 m/s (15 and 20 mph) unpadded and 9 m/s padded tests. The following padding was used at the thorax: ARSAN, ARCEL, ARPAK, ARPRO, DYTHERM, 103 and 159 kPa (15 and 23 psi) crush strength paper honeycomb, and an expanded polystyrene. In all padded tests the dummy Thoracic Trauma Index, TTI(d) was below the value of 85 set by federal rulemaking (49 CFR, Part 571 et al., 1990). In contrast, cadavers in 9 m/s sled tests did not tolerate ARSAN 601 (MAIS 5) and 23 psi (159 kPa) paper honeycomb (MAIS 5), and 20 psi (138 kPa) Verticel™ honeycomb (MAIS 4), but tolerated 15 psi (103 kPa) paper honeycomb (average thoracic MAIS 2.3 in six tests).

Requirements for reduced fuel consumption with simultaneous reductions in regulated emissions require more efficient operation of Spark Ignited (SI) engines. An advanced valvetrain coupled with Gasoline Direct injection (GDi) provide an opportunity to simultaneously reduce fuel consumption and emissions. Work on a flex fuel GDi engine has identified significant potential to reduce throttling by using Early Intake Valve Closing (EIVC) and Late Intake Valve Closing (LIVC) strategies to control knock and load. High loads were problematic when operating on gasoline for particulate emissions, and low loads were not able to fully minimize throttling due to poor charge motion for the EIVC strategy. The use of valve deactivation was successful at reducing high load particulate emissions without a significant airflow penalty below 3000 RPM. Valve deactivation did increase the knocking tendency for knock limited fuels, due to increased heat transfer that increased charge temperature.

Advanced valvetrain coupled with Direct Injection (DI) provides an opportunity to simultaneous reduction of fuel consumption and emissions. Because of their robustness and cost performance, multi-hole injectors are being adopted as gasoline DI fuel injectors. Ethanol and ethanol-gasoline blends synergistically improve the performance of a turbo-charged DI gasoline engine, especially in down-sized, down-sped and variable-valvetrain engine architecture. This paper presents Mie-scattering spray imaging results taken with an Optical Accessible Engine (OAE). OAE offers dynamic and realistic in-cylinder charge motion with direct imaging capability, and the interaction with the ethanol spray with the intake air is studied. Two types of cams which are designed for Early Intake Valve Close (EIVC) and Later Intake Valve Close (LIVC) are tested, and the effect of variable valve profile and deactivation of one of the intake valves are discussed.

Injuries to the thorax and abdomen comprise a significant percentage of all occupant injuries in motor vehicle accidents. While the percentage of internal chest injuries is reduced for restrained front-seat occupants in frontal crashes, serious skeletal chest injuries and abdominal injuries can still result from interaction with steering wheels and restraint systems. This paper describes the design and performance of prototype components for the chest, abdomen, spine, and shoulders of the Hybrid III dummy that are under development to improve the capability of the Hybrid III frontal crash dummy with regard to restraint-system interaction and injury-sensing capability.

A 3-D finite element human head model has been developed to study the dynamic response of the human head to direct impact by a rigid impactor. The model simulated closely the main anatomical features of an average adult head. It included the scalp, a three-layered skull, cerebral spinal fluid (CSF), dura mater, falx cerebri, and brain. The layered skull, cerebral spinal fluid, and brain were modeled as brick elements with one-point integration. The scalp, dura mater, and falx cerebri were treated as membrane elements. To simulate the strain rate dependent characteristics of the soft tissues, the brain and the scalp were considered as viscoelastic materials. The other tissues of the head were assumed to be elastic. The model contains 6080 nodes, 5456 brick elements, and 1895 shell elements. To validate the head model, it was impacted frontally by a cylinder to simulate the cadaveric tests performed by Nahum et. al. (8).

There are many mechanisms for ankle injury to front seat occupants involved in automotive impacts. This study addresses injuries to the ankle joint involving inversion or eversion, in particular at high rates of loading such as might occur in automotive accidents. Injuries included unilateral malleolar fractures and ligament tears, and talus and calcaneous avulsions. Twenty tests have been performed so far, two of them using Hybrid III lower leg and the rest using cadaveric specimens. The specimens were loaded dynamically on the bottom of the foot via a pneumatic cylinder in either an inversion or eversion direction at fixed dorsiflexion and plantarflexion angles. The applied force and accelerations have been measured as well as all the reaction forces and moments. High-speed film was used to obtain the inversiordeversion angle of the foot relative to the tibia and for following ligament stretch.

Port fuel injection system in gasoline engines is receiving an increasing attention for its potential advantages in meeting the constrains of simultaneous reduction in fuel consumption and exhaust emission, and maintaining a good engine performance. The structure of port injector spray dominates the mixture preparation process and strongly affect the subsequent engine combustion characteristics over a wide range of operating conditions in port-injection gasoline engines. In this paper, an experimental and analytical study is made to characterize the breakup mechanism and atomization process of the non-air-assisted port injector sprays in gasoline engines. The liquid sprays resulted from various types of current and development-type automotive fuel injectors were visualized using planar laser-induced fluorescence imaging technique. A comparison was made on the spray structure of the single hole and multi-hole injectors.

A global characterization of the spray distribution of various current and development types of automotive fuel injectors was obtained. Axial and radial measurement of droplet sizes, velocities and volume fluxes were made with a phase Doppler particle analyzer (PDPA) for a transient port injector spray in quiescent atmospheric conditions. Time-resolved measurements involving the time-of-arrival of each droplet associated with its size and velocity components were also acquired. Additionally, the liquid sprays emanating from various types of port fuel injectors were visualized, through planar laser induced fluorescence (PLIF) technique, at different time instants. Such detailed study provides an improved understanding of the temporal or unsteady behavior of port injector spray.