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The 9 papers in this technical paper collection focus on fire safety. Topics covered include hot surface ignition, oxidation on steel surfaces, standard tests for assessing the effectiveness of transit vehicle fire extinguishing systems, and more. The 9 papers in this technical paper collection focus on fire safety. Topics covered include hot surface ignition, oxidation on steel surfaces, standard tests for assessing the effectiveness of transit vehicle fire extinguishing systems, and more.

The 14 papers in this technical paper collection cover automotive lighting technology and human factors in driver vision and lighting. Topics discussed include LED design and applications, signal lighting, side view cameras, red light cameras, high dynamic range photography, and more. The 14 papers in this technical paper collection cover automotive lighting technology and human factors in driver vision and lighting. Topics discussed include LED design and applications, signal lighting, side view cameras, red light cameras, high dynamic range photography, and more.

This technical paper collection focuses on current developments in the fields of vehicle fire science, statistics, risks, assessment and mitigation. Papers addressing vehicle design, live-fire tests and fire investigation issues applicable to traditional, electric and alternatively fueled vehicles are included.

Abstract Carbon fiber reinforced plastic (CFRP) has been used in automobiles as well as airplanes. Because of its light weight and high strength, CFRP is a good choice for making vehicle bodies lighter, which would improve fuel economy. Conventional metal bodies provide a convenient body return for electric wiring and offer good shielding against electromagnetic fields. Although CFRP is a conductor, its conductivity is much lower than that of metals. Therefore, CFRP bodies are usually not useful for electric wiring. In thunderstorms, an automotive body is considered to be a Faraday cage that protects the vehicle’s occupants from the potential harms of lightning. Before CFRP becomes widely applied to automotive bodies, its electric and electromagnetic properties need to be investigated in order to determine whether it also works as a Faraday cage against lightning. In this article, CFRP and metal body vehicles were tested under artificial lightning.

A laboratory study was performed to assess the effects of SO2 poisoning on the NOx conversion of iron (Fe) and copper (Cu) SCR catalysts. Thermally aged samples of the catalysts were poisoned with SO2 under lean conditions. At various times during the poisonings, the samples were evaluated for NOx conversion with NO and NH3 using lean temperature ramps. The low temperature NOx conversions of both catalysts decreased by 10 to 20% after 1 to 4 hours of poisoning but were stable with continued exposure to the SO2. The poisoned Cu SCR catalyst could be desulfated repeatedly with 5 minutes of lean operation at 600°C. Initially, the poisoned Fe SCR catalyst required 5 minutes of lean operation at 750°C to recover its maximum NOx conversion.

This SAE Information Report describes results of testing of the SAE J1746 ISP-Vehicle Standard for the communication of spatial data references between central sites and mobile vehicles on roads. Testing was performed by the Oak Ridge National Laboratory and its contractors, resulting in a document from which this Information Report has been extracted. Tests were performed by computer analysis and corroborated by field tests with a mobile vehicle.

A brief explanation of the design iterations and philosophy used to integrate the pilot into the F-35 Lightning II cockpit to achieve optimum Pilot Vehicle Interface (PVI), manageable single seat workload, and superior situation awareness.

Mixture formation in an optically accessible hydrogen-fueled engine was investigated using Planar Laser-Induced Fluorescence (PLIF) of acetone as a fuel tracer. The engine was motored and fueled by direct high-pressure injection. This paper presents the evolution of the spatial distribution of the ensemble-mean equivalence ratio for six different combinations of nozzle design and injector geometry, each for three different injection timings after intake-valve closure. Asymmetric single-hole and 5-hole nozzles as well as symmetric 6-hole and 13-hole nozzles were used. For early injection, the low in-cylinder pressure and density allow the jet to preserve its momentum long enough to undergo extensive jet-wall and (for multi-hole nozzles) jet-jet interaction, but the final mixture is fairly homogeneous. Intermediately timed injection yields inhomogeneous mixtures with surprisingly similar features observed for all multi-hole injectors.

A laboratory study was performed to assess the effects of sulfur poisoning and desulfation temperature on the NO conversion of a LNT+(Cu/SCR) in-situ system. Four LNT+(Cu/SCR) systems were aged for 4.5 hours without sulfur at 600, 700, 750, and 800°C using A/F ratio modulations to represent 23K miles of desulfations at different temperatures. NO conversion tests were performed on the LNT alone and on the LNT+SCR system using a 60 s lean/5 s rich cycle. The catalysts were then sulfur-poisoned at 400°C and desulfated four times and re-evaluated on the 60/5 tests. This test sequence was repeated 3 more times to represent 100K miles of desulfations. After simulating 23K miles of desulfations, the Cu-based SCR catalysts improved the NO conversion of the LNT at low temperatures (e.g., 300°C), although the benefit decreased as the desulfation temperature increased from 600°C to 800°C.

In-cylinder spray imaging by Mie scattering has been taken with frame rates up to 27,000 fps, along with high speed video photography of chemiluminescence and soot thermal radiation. Spectroscopic measurements have confirmed the presence of OH*, CH* and C2* emissions lines, and their magnitude relative compared to soot radiation. Filtering for CH* has been used with both the high speed video and a Photo-Multiplier Tube (PMT). The PMT signals have been found to correlate with the rate of heat release derived from in-cylinder pressure measurements. A high power photographic strobe has been used to illuminate the fuel spray. Images show that the fuel spray can strike the ground strap of the spark plug, break up, and a fuel cloud then drifts over and under the strap through the spark plug gap. Tests have conducted at two different spark plug orientations using a single spark strategy.

In the automotive industry, the use of beading is widely spread. Beads are primarily used to stiffen the floor and dash panels. The aim is to reduce vibration levels and hopefully at the same time reduce radiated noise. Beading has a positive effect close to the first panel mode's natural frequency however it can have a negative effect at all other frequencies. Typically, engineers assume a radiation efficiency of “1” (one) over the whole frequency range for simplicity or lack of available implemented formulation in their simulation tools. This assumption directs the investigation at reducing the vibration levels only. This approach can be misleading because even though radiation efficiency tends to “1” (one) above coincident frequency it is not the case below coincidence. While increasing stiffness reduces vibration levels, it also increases radiation efficiency. This can yield to higher levels of radiated noise.

The knock metric for controlled auto-ignition (CAI) engines is assessed by considering the physical processes that establish the pressure wave that contributes to the acoustic radiation of the engine, and by analyzing pressure data from a CAI engine. Data sets from the engine operating with port fuel injection, early direct injection and late direct injection are used to monitor the effect of mixture composition stratification. Thermodynamic analysis shows that the local pressure rise produced by heat release has to be discounted by the work spent in acoustic expansion against the ambient pressure to properly predict the pressure wave amplitude. Based on this analysis, a modified correlation between the pressure wave amplitude and the maximum pressure rise rate (MPRR) is developed by introducing an MPRR offset to account for the expansion work.

In this paper we present a time-domain dynamic analysis of a helical gear box with different housing models using a unique finite element-contact mechanics solver. The analysis includes detail contact modeling between gear pairs along with the dynamics of gear bodies, shafts, bearings, etc. Inclusion of the housing in the dynamic analysis not only increases the fidelity of the model but also helps estimate important NVH metrics, such as dynamic load and vibration transmission to the base, sound radiation by the gearbox, etc. Two different housing models are considered. In the first, the housing is represented by a full FE mesh, and in the second, the housing is replaced by a reduced model of condensed stiffness and mass matrices. Component Mode Synthesis (CMS) methods are employed to obtain the reduced housing model. Results from both the models are successfully compared to justify the use of reduced housing model for further studies.

Exhaust noise is a major contributor to the radiated noise level of a vehicle, especially at idle. The radiated noise level has to meet a certain criteria based on regulation and consumer demand. In many cases, the problem appears after the vehicle is manufactured and the tailpipe noise measurement is performed indicating a high noise level that needs to be reduced. This paper describes one of those cases where the radiated noise level of a certain passenger car at idle was required to be reduced by 6 dB(A). The exhaust system consists of one main muffler and one auxiliary muffler. A 1D two-port model of the exhaust system including the two mufflers was built using commercial software. This model was validated against the measurement of the two-port matrix of both mufflers. The model was then used together with tailpipe noise measurements to estimate the characteristics of the source strength and impedance.

Engine torque profile shaping strategies have been proposed to reduce noise & vibration for passenger cars. However, it has not been sufficiently studied that feasible torque profile for vibration suppression is dependent on engine speed and target torque shape. On the other hand, combustion pressure profile shaping strategies have been proposed to reduce noise. However, there is almost no research of the quantitative evaluation of contribution of combustion pressure profile. First, the torque profile shaping was studied. Pre-compensated torque and 2-step torque were selected as typical target torque profiles. An effectiveness of vibration suppression by two torque profiles was evaluated by both drivetrain vibration model and engine torque profile model which have been established well. As a result of studying the torque profile shaping, timing of torque rise by the 2-step torque generation is delayed or advanced.

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.

Pilot injection (PI) during the negative-valve-overlap (NVO) period is one method to improve control of combustion in gasoline controlled auto-ignition engines. This is generally attributed to both chemical and thermal effects. However, there are little experimental data on active species formed by the combusting PI and their effect on main combustion in real engines. Thus, it is the objective of the current study to apply and assess optical in-cylinder diagnostics for these species. Firstly, the occurrence and nature of combustion during the NVO period is investigated by spectrally-resolved multi-species flame luminescence measurements. OH*, CH*, HCO*, CO-continuum chemiluminescence, and soot luminosity are recorded. Secondly, spectrally-, spatially-, and cycle-resolved laser-induced fluorescence measurements of formaldehyde are conducted. It is attempted to find a cycle-resolved measure of the chemical effect of PI.

In the present paper we introduce a monolithic CFD approach to simulate the cooling-down characteristics of disk brakes. To ensure a strong coupling between fluid and solid domain the overall transient thermal problem is solved within a single flow solver during the complete cooling-down process. We employ a fully implicit second order solution procedure. The experimental configuration consists of an inertia dynamometer including a generic 17 inch vented front disk with caliper, dust shield, bearing and knuckle. The validation is carried out for three different air flow velocities, with and without dust shield. The temperature is monitored via two thermocouples embedded into outer and inner rotor cheeks. In order to quantify the cooling-down characteristics, regression analysis are conducted on the temperature curves. The obtained cooling coefficient serves as comparison between measurement and computation.

To promote advanced combustion strategies complying with stringent emission regulations of CI engines, computational models have to accurately predict the injector inner flow and cavitation development in the nozzle. This paper describes a coupled 1D/2D/3D modeling technique for the simulation of fuel flow and nozzle cavitation in diesel injection systems. The new technique comprises 1D fuel flow, 2D multi-body dynamics and 3D modeling of nozzle inner flow using a multi-fluid method. The 1D/2D model of the common rail injector is created with AVL software Boost-Hydsim. The computational mesh including the nozzle sac with spray holes is generated with AVL meshing tool Fame. 3D multi-phase calculations are performed with AVL software FIRE. The co-simulation procedure is controlled by Boost-Hydsim. Initially Hydsim performs a standalone 1D simulation until the needle lift reaches a prescribed tolerance (typically 2 to 5 μm).

Cooperative collision warning (CCW) systems use communication networks as a main component for creating situational awareness and eventually hazard detection. Simulation and analysis of such systems are generally more complicated due to the system being composed of components from very different domains of communication and vehicle safety. These components are inherently developed and modeled in different domains, as their basic operations are usually defined and engineered by researchers from different disciplines. Creating a simulation tool for CCW systems requires combining simulation models that are developed using different methodologies. As a result, a unified tool for study of such systems is not readily available. In this paper, we describe a co-simulation tool that models both components of communication and hazard prediction in one framework. The tool uses several different levels of abstraction for the communication model, while modeling the application in a precise manner.