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Further improvements in catalyst performance are required to help protect the atmospheric environment. However, from the viewpoint of resource availability, it is also necessary to decrease the amount of precious metals used at the active sites of the catalyst. Therefore, a high-performance three-way catalyst with an advanced coating layer has been developed to lower the amount of precious metal usage. Fuel efficiency improvement technologies such as high compression ratios and a large-volume exhaust gas recirculation (EGR) generally tend to increase the ratio of hydrocarbons (HC) to nitrogen oxides (NOx) in exhaust gas. This research focused on the palladium (Pd) loading depth in the coating layer with the aim of improving the hydrocarbon (HC) conversion activity of the catalyst.

Many side-impact collisions occur at speeds much lower than tests conducted by the National Highway Traffic Safety Administration (NHTSA) and the Insurance Institute for Highway Safety (IIHS). In fact, nearly half of all occupants in side-impact collisions experience a change in velocity (delta-V) below 15 kph (9.3 mph). However, studies of occupant loading in collisions of low- to moderate-severity, representative of many real-world collisions, is limited. While prior research has measured occupant responses using both human volunteers and anthropometric test devices (ATDs), these tests have been conducted at relatively low speeds (<10 kph [<6.2 mph] delta-V). This study evaluated near- and far-side occupant response and loading during two side impacts with delta-V of 6.1 kph and 14.0 kph (3.8 mph and 8.7 mph).

The impact of transport on global and local pollution has resulted in stricter emission limits. More specifically, increasing attention is being paid to exhaust gas particulate emissions in spark ignition engines. The particulate formation is mainly affected by: 1-engine and fuel system characteristics, 2-fuel properties and 3-exhaust aftertreatment system. In order to estimate the influence of fuel characteristics on particulate emissions, several research works have proposed fuel indices that correlate some of the fuel physical and chemical properties with engine particulate emissions. This work investigates the impact of fuel composition on particulate emissions and evaluates the Honda Particulate Matter Index (PMI) proposed by Aikawa et al. and other fuel indices in terms of agreement with vehicle test bed results for a passenger car.

Social interest in global environmental issues has remained in the forefront during recent years, and as a result, internal combustion engines are expected to have further improved fuel efficiency and reduced exhaust emissions. General purpose engines are demanded for reduced cost in addition to various types of displacement developments. If optimum specifications are examined for each engine displacement and incorporated in the parts shapes, the number of dedicated parts for each engine displacement would increase, which is not desirable from a development/production cost-wise standpoint. It is considered important during the development of engines to efficiently and economically cope with market needs including improved specific power and fuel consumption. Therefore, it was considered necessary to improve combustion performance by enhanced in-cylinder flow and to commonize parts.

The prediction of the connecting rod behaviour is one of the most important aspects of the engine design to estimate the engine life and its NVH behaviour. Connecting rod is usually simulated as a stand-alone component replacing the connected members with boundary conditions. These kinds of simulation usually underestimate the life of the connecting rod and overestimate the crankpin distortion. This unreal behaviour of simulation can result in over design of the crankshaft and wrong crankpin bearing selection, which can result in a noisy engine. The current Finite Element Analysis (FEA) is modelled by considering crankshaft, bearings, 3D bolts and crankcase substructure along with the connecting rod to predict the fatigue life and bearing distortion. A multi-body dynamics (MBD) simulation of the Cranktrain has been carried out to predict the forces and accelerations on the connecting rod by including the combustion force with a constant crankshaft speed for different conditions.

Gasoline Direct Injection (GDI) engines show advantages in reducing fuel consumption and gaseous pollution emissions when compared to Port Fuel Injection (PFI) engines. However, particulate matter emissions are an essential issue for GDI engine development due to increasingly stringent worldwide emission regulations. Previous studies have shown that gasoline fuel compositions, as well as deposits formed in GDI fuel injectors, can affect emissions in the GDI engine. In this work, the impact of gasoline fuel properties on forming injector deposits and the resulting effect on particulate emissions were investigated using a modern Chinese GDI engine. Six test fuels with different properties involving changes in olefins, aromatics, heavy (C9/C9+) aromatics, T90 and deposit control additive (DCA) were prepared based on the gasoline survey results from the Chinese gasoline fuel market and the China 6 gasoline fuel standard limits.

Instrumented human subject and anthropomorphic test device (ATD) responses to low speed lateral impacts were investigated. A series of 12 lateral collisions at various impact angles were conducted, 6 near-side and 6 far-side, with each test using an ATD and one human subject. Two restrained female subjects were utilized, with one positioned in the driver seat and one in the left rear seat. Each subject was exposed to 3 near-side and 3 far-side impacts. The restrained ATD was utilized in both the driver and left rear seats, undergoing 3 near-side and 3 far-side impacts in each position. The vehicle center of gravity (CG) change in velocity (delta-V) ranged from 5.5 to 9.4 km/h (3.4 to 5.8 mph). Video analysis was used for quantification and comparison of the human and ATD motions and interactions with interior vehicle structures. Human head, thorax, and low back accelerations were analyzed. Peak human subject head resultant accelerations ranged from 0.9 to 36.8 g’s.

Over the past decade, there has been an increase in awareness and concern about the occurrence and long-term effects of concussions. Traumatic brain injury (TBI)-related emergency department (ED) visits associated with motor vehicle collisions, including patients with a diagnosis of concussion or mild TBI (mTBI), have increased while deaths and hospital admissions related to TBI have decreased. The diagnostic criteria for concussion have evolved and broadened, and based on current assessments and diagnostic imaging techniques, there are often no objective findings, yet a diagnosis of concussion may still be rendered. Clinical assessment of concussion may be based only on patient-reported symptoms and history, making it difficult to objectively relate the reported increase in TBI-related ED visits due to motor vehicle collisions to specific collision parameters.

Separate from the event data recorder (EDR), which records and stores data from qualifying vehicle crash events, the Vehicle Control History (VCH) on Toyota vehicles records and stores certain vehicle data based on select driver inputs, such as hard acceleration or braking, or upon the activation of certain vehicle dynamic control systems such as antilock braking system (ABS), traction control (TRAC), vehicle stability control (VSC), and the pre-collision system (PCS). In the United States, VCH was first equipped on the 2013 Toyota RAV4 and has been subsequently introduced into other Toyota and Lexus models. Most recently, in addition to VCH data, additional PCS operational data (PCS-O) and image data (PCS-I) may be recorded and stored. The image storage capability may record under certain conditions such as if the system has automatically applied the vehicle brakes.

Low- to moderate-speed motor vehicle collisions are common roadway occurrences that are generally associated with low rates of reported injury. While such complaints are generally infrequent, claims of injuries resulting from low- to moderate-speed motor vehicle collisions persist. A limited body of literature using quantitative techniques and full-scale crash tests is available to assess the injury potential associated with such collisions. Prior studies have analyzed occupant kinematics and kinetics as well as human injury risk in low- to moderate-speed collisions with older vehicle vintages but do not assess the effects of updated vehicle interior designs and occupant protection devices reflective of efforts to optimize occupant kinematics and reduce occupant loading and injury risk in more modern vehicles.

Disc herniations in the spine are commonly associated with degenerative changes, and the prevalence increases with age. Though rare, spinal disc herniations can also be caused by trauma. With increasing number of older drivers on U.S. roads, there is an expected proportionate increase in clinical findings of disc herniations in occupants involved in vehicle impacts. Our goal in this study is to determine whether there is a causal relationship between frontal impacts and the occurrence of disc herniations in the occupants of these impacts. We further aim to determine the prevalence of different types of spinal injury and to evaluate the effects of crash severity and other parameters on different types of spinal injury in such impacts. Using data from the National Automotive Sampling System - Crashworthiness Data System (NASS-CDS) database from 1993 through 2014, we examined the reported occurrence of all spine injuries for adult occupants in frontal impact.

Engine cylinder pressure is traditionally measured with a piezo-electric pressure transducer, and as such, must be referenced or pegged to a known value. Frequently, the cylinder pressure is pegged to the pressure in the intake manifold plenum whereby the manifold absolute pressure (MAP) at the end of the intake stroke is measured and the cylinder pressure trace for the entire cycle is adjusted such that the cylinder pressure is set equal to the manifold pressure at the end of the intake stroke. However, any error in pegging induces an error in the cylinder pressure trace, which has an adverse effect on the entire combustion analysis. This research is focused on assessing the pegging error for several pegging methods across a wide range of engine operating conditions, and ultimately determining best practices to minimize error in pegging and the calculated combustion metrics. The study was conducted through 1D simulations using the commercially available GT-Power.

Autonomous Vehicle Disengagement Reports have been published by the California Department of Motor Vehicles since 2015. The State of California autonomous vehicle testing regulations require every manufacturer authorized to test autonomous vehicles on public roads to submit an annual report summarizing disengagements. In early versions of the annual report, automated vehicle manufacturers were required to provide the time that it took for a human driver to take manual control of the vehicle when reporting vehicle disengagements. This study analyzes reported automated vehicle disengagement reaction times from 2015 through 2017 for various manufacturers that provided information to the California Department of Motor Vehicles while operating vehicles in autonomous mode. This study compares the reported automated vehicle operation disengagement reaction time to field literature in testing and experimentation on human brake reaction times for both automobile and motorcycle operation.

Knowing the tire pressure during driving is essential since it affects multiple tire properties such as rolling resistance, uneven wear, and how prone the tire is to tire bursts. Tire temperature and cavity pressure are closely tied to each other; a change in tire temperature will cause an alteration in tire cavity pressure. This article gives insights into which tire temperature measurement position is representative enough to estimate pressure changes inside the tire, and whether the pressure changes can be assumed to be nearly isochoric. Climate wind tunnel and road measurements were conducted where tire pressure and temperature at the tire inner liner, the tire shoulder, and the tread surface were monitored. The measurements show that tires do not have a uniform temperature distribution. The ideal gas law is used to estimate the tire pressure from the measured temperatures.

Centrifugal fans are applied in many industrial and civil applications, such as manufacturing processes and building HVAC systems. They can also be found in automotive applications. Noise-reduction measures for centrifugal fans are often challenging to establish, as acoustic performance may be considered a tertiary purchase criterion after energetic efficiency and price. Nonetheless, their versatile application raises the demand for noise control. In a low-Mach-number centrifugal fan, acoustic waves are predominantly excited by aerodynamic fluctuations in the flow field and transmit to the exterior via the housing and duct walls. The scientific literature documents numerous mechanisms that cause flow-induced sound generation, even though not all of them are considered well-understood. Numerical simulation methods are widely used to gather spatially high-resolved insights into physical fields.

Seat mounted side impact airbags (SIAB) along with side curtain airbags are now a standard passive safety equipment offered by nearly all original equipment manufacturers (OEM) to meet side protection requirements in many regions of the world. While the side curtain airbag is intended to reduce head injury, the SIAB protects the thorax and abdomen region of the driver or passenger in a side crash scenario. An optimized SIAB both in terms of design and deployment threshold has the potential to reduce occupant’s injury level and can prevent fatalities. Because of the limited space available between the occupant and the side structure of the vehicle, there are significant challenges posed for packaging a SIAB to provide adequate cushioning distance from the intruding parts of the vehicle side structure and spread the impact load over a larger area. Different regulatory requirements in different geographies add further challenges for a common design.

Event data recorders (EDRs) were harvested and imaged after Insurance Institute for Highway Safety (IIHS) 56 km/hr frontal and 64.4 km/hr frontal offset crashes of 15 different brands of 2016-2022 vehicles. The speed and delta-V in the EDR were compared to reference instrumentation. Speed data was accurate within the generally accepted range of +/-4%. The 40% overlap tests had generally similar vehicle kinematics, and their delta-Vx data was accurate. However, there was a much greater variance in the small (25%) overlap tests. Some outliers in the small overlap delta-Vx tests required further analysis using overhead video analysis. The video analysis more closely matched the EDR recorded values. These offset tests create significant post-crash rotation, and both EDR and IIHS instrumentation were affected by their location away from the center of gravity. The Y-axis was affected much more than the X-axis.

The prediction accuracy of a three-way catalyst (TWC) model is highly associated with the ability of the model to incorporate the reaction kinetics of the emission process as a lambda function. In this study, we investigated the O2 and H2 concentration profiles of TWC reactions and used them as critical inputs for the development of a global TWC model. We presented the experimental data and global kinetic model showing the impact of thermal degradation on the performance of the TWC. The performance metrics investigated in this study included CH4, NOx, and CO conversions under lean, rich, and dithering light-off conditions to determine the kinetics of oxidation reactions and reduction/reforming/water-gas shift reactions as a function of thermal aging. The O2 and H2 concentrations were measured using mass spectrometry to track the change in the oxidation state of the catalyst and to determine the mechanism of the reactions under these light-off conditions.

NHTSA released the FMVSS226 Standard in 2011, and defined the requirements for ejection mitigation systems, which limit the linear travel of headform by 100mm. In China regulations, there are similar requirements starting in 2021. Therefore, on the basis of the existing airbag design, adding the rollover protection function becomes a challenge for the airbag development. During the development of the curtain airbag, the cushion design, inflator type, and the fold pattern, all have an important influence on the airbag unfolding direction, the airbag positioning time and the airbag internal pressure, and then significantly affect the occupant protection performance afterwards. In order to reduce the cost and shorten the development time, it is necessary to predict the process of cushion deployment kinematics and the internal pressure of the airbag with high refinement, and based on it to predict and evaluate the FMVSS226 ejection mitigation performance.

China VI standards for heavy duty vehicles require that the mileage of CNG catalysts for vehicles with a maximum design total mass of more than 18 tons should reach 700000 km. In order to quickly evaluate the durability of CNG catalyst, muffle furnace aging and natural gas engine bench aging were usually adopted. The advantages of muffle furnace aging were simple operation, short time and low cost, but the aging atmosphere is quite different from the exhaust atmosphere of natural gas engine, which is difficult to reflect the actual durability of the catalyst. The aging of natural gas engine can reflect the durability of the catalyst, but it usually takes about 1000 hours. Due to long time, and high cost, it is difficult to be widely applied in the early stage of catalyst development. Therefore, it is a very interesting research direction to develop new methods with the advantages of muffle furnace aging and natural gas bench aging.