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This paper describes a study to determine the influence of preimpact vehicle braking on the positions and postures of unrestrained, children in the front seat at the time of collision. Anesthetized baboons were used as child surrogates. The unrestrained animals were placed in various initial sitting, kneeling, and standing positions typically assumed by children while traveling in automobiles. Tests were conducted with various front seat positions and seat covering materials. Measurements were made of pertinent vehicle dynamics and surrogate kinematics during the hard braking event. For each initial condition evaluated, a photosequence is given showing typical positions and postures of the surrogate during the braking event.

A new generation of vehicle dynamics and powertrain control technologies are being developed to leverage information streams enabled via vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) connectivity [1, 2, 3, 4, 5]. While algorithms that use these connected information streams to enable improvements in energy efficiency are being studied in detail, methodologies to quantify and analyze these improvements on a vehicle have not yet been explored fully. A procedure to test and accurately measure energy-consumption benefits of a connected and automated vehicle (CAV) is presented. The first part of the test methodology enables testing in a controlled environment. A traffic simulator is built to model traffic flow in Fort Worth, Texas with sufficient accuracy. The benefits of a traffic simulator are two-fold: (1) generation of repeatable traffic scenarios and (2) evaluation of the robustness of control algorithms by introducing disturbances.

The design of helical Intake ports for swirl generation is a process that has been developed over a number of years through primarily empirical methods. A number of design rules have been established that enable designers to develop ports that approach the state-of-the-art for maximum swirl generation with minimum pressure loss. More recently, computer-aided design (CAD) tools have been introduced that permit geometry and features to be accurately defined by mathematical surface descriptions, and to be parameterized such that derived geometry is updated automatically along with parent features. The author has developed a parametric design approach for helical ports that incorporates the lessons learned from experience into a systematic design procedure. This procedure takes advantage of the current CAD capabilities to expedite the design process and improve the result.

Atmospheric corrosion of steels, aluminum alloys, and Al-clad aluminum alloys is a problem for many civil engineering structures, commercial and military vehicles, and aircraft. Paint is usually the primary means to prevent the corrosion of steel bridge components, automobiles, trucks, and aircraft. Under ideal conditions, the coating provides a continuous layer that is impervious to moisture. At present, maintenance cycles for commercial and military aircraft and ground vehicles, as well as engineered structures, is based on experience and appearance rather than a quantitative determination of coating integrity. To improve the maintenance process and reduce costs, sensors are often used to monitor corrosion. The present suite of sensors designed to detect corrosion and marketed to predict the lifetime of the engineered components, however, are not useful for determining the condition of the protective paint coatings.

SCR-on-filter, or SCRoF, is an emerging technology for different market segments and vehicle applications. The technology enables simultaneous particulate matter trapping and NOX reduction, and provides thermal management and aftertreatment packaging benefits. However, there is little information detailing the lubricant derived exposure effects on functional SCR performance. A study was conducted to evaluate the impact of various oil consumption pathways on a light duty DOC and SCRoF aftertreatment system. This aftertreatment system was aged utilizing an engine test bench modified to enable increased oil consumption rates via three unique oil consumption pathways. The components were characterized for functional SCR performance, ash morphology, and ash deposition characteristics. This included utilizing techniques, such as SEM / EDS, to evaluate the ash structures and quantify the ash elemental composition.

Due to the serious need of the U.S. Army for a simple and rapid mobile fuel filtration system, a Filtration/Additive Unit (FAU) has been designed and fabricated. The primary use of the FAU is to aid in the cleanup of fuel in Army ground vehicles and equipment fuel cells and storage tanks. The FAU provides a simple and rapid means to remove gross quantities of particulate and water. The unit consists of a trailer-mounted filtration and additive system capable of dispensing three separate additives into the fuel. The FAU was designed to rapidly clean and additive-treat diesel or aviation-type fuels in volumes between 400 and 4500 liters. However, the FAU is capable of processing larger quantities, such as in storage tanks. The designed pump rate is 225 liters per minute (minimum) using diesel fuel at its maximum viscosity (4.1 cSt at 40°C).

Typical two-site storage-based SCR plant models in literature consider NH3 stored in the first site to participate in NH3 storage, NOx conversion and second site to only participate in NH3 storage passively. This paper focuses on quantifying the impact of stored NH3 in the second site on the overall NOx conversion for an ultra-low NOx system due to intra site NH3 mass transfer. Accounting for this intra site mass transfer leads to better prediction of SCR out NH3 thus ensuring compliance with NH3 coverage targets and improved dosing characteristics of the controller that is critical to achieving ultra-low NOx standard. The stored NH3 in the second site undergoes mass transfer to the first site during temperature ramps encountered in a transient cycle that leads to increased NOx conversion in conditions where the dosing is switched off. The resultant NH3 coverage fraction prediction is critical in dosing control of SCR.

Natural gas vehicle (NGV) fuel energy storage density is a key issue, particularly in many heavy-duty applications where compressed natural gas may have unattractively low energy density. For these uses, benefits can be derived by using liquefied natural gas (LNG). From a market perspective, LNG can play a role for transportation because it is available in various areas of the United States and throughout the world. This paper provides a general overview of LNG use for vehicles and specifically an analysis of factors governing the behavior of this cryogenic fluid in a confined vessel. This is intended to provide an understanding of the cause/effect relation between LNG fuel composition, tank heat influx, and rate of fuel usage or storage time.

An experimental program was designed to determine friction characteristics between brake pads and metal rotors that could indicate a brake fluid's propensity to cause chatter in wet-brakes. Friction was measured on a bench version of the John Deere wet-brake qualification system. Rotor and pad supports were made very rigid to avoid chatter in the simulator. One type of pad was run on cast-iron and mild steel rotors using two reference oils, one giving unacceptable levels of chatter and the other giving acceptable levels as previously determined in full-scale tests on the Deere system. The outstanding discriminating characteristic was the drop in friction from breakaway of the pad from the rotor. The ratio of the initial drop in the friction coefficient between unacceptable and acceptable oils for all conditions of the testing ranged from 1.7 to 2.0

Changing fuel quality, increasingly stringent exhaust emission standards, demands for higher efficiency, and the trend towards higher specific output, all contribute to the need for a better understanding of the ignition process in diesel engines. In addition to the impact on the combustion process and the resulting performance and emissions, the ignition process controls the startability of the engine, which, in turn, governs the required compressions ratio and several of the other engine design parameters. The importance of the ignition process is reflected in the fact that the only combustion property that is specified for diesel fuel is the ignition delay time as indicated by the cetane number. The objective of the work described in this paper was to determine the relationship between the ignition process as it occurs in an actual engine, to ignition in a constant volume combustion bomb.

The specific goal of this project was to determine if there is a difference in the lube oil degradation rates in a heavy-duty diesel engine equipped with an EGR system, as compared to the same configuration of the engine, but minus the EGR system. A secondary goal was to develop FTIR analysis of used lube oil as a sensitive technique for rapid evaluation of the degradation properties of lubricants. The test engine selected for this work was a Caterpillar 3176 engine. Two engine configurations were used, a standard 1994 design and a 1994 configuration with EGR designed to meet the 2004 emissions standards. The most significant changes in the lubricant occurred during the first 50-100 hours of operation. The results clearly demonstrated that the use of EGR has a significant impact on the degradation of the engine lubricant.

Recent internal research performed at SwRI examined an emissions control mechanism that we have labeled, ‘phased A/F perturbation.’ The suggested mechanism of phased perturbation involves independently controlling the fuel delivered to each bank of a dual bank engine, which allows the two banks to have an adjustable, relative A/F perturbation phase-shift from one another. Exhaust from the two banks can be combined to achieve a near-stoichiometric mixture prior to entering a single underbody catalyst. Since both rich and lean exhaust species would be present simultaneously, a highly reactive mixture would continuously enter the catalyst. In that work, it was found that A/F phasing produced as significant an effect on conversion efficiency as perturbation amplitude and frequency, i.e. A/F phasing was identified as a third dimension for optimization of exhaust gas composition as it enters the catalyst.

A novel urea evaporation and mixing device has been developed to improve the overall performance of a urea-SCR system. The device was tested with a MY2007 Cummins ISB 6.7L diesel engine equipped with an SCR aftertreatment system. Test results show that the device effectively improved the overall NO conversion efficiency of the SCR catalyst over both steady-state and transient engine operating conditions, while NH₃ slip from the catalyst decreased.

This paper describes the development and evaluation of an operative catalyst for the reduction of NOx in lean exhaust. A catalyst that incorporates iron (II)-complex impregnated modified mesoporous molecular sieves (MCM-41) has been synthesized and further treated with [pd(NH3)4]Cl2 [1]. Experimental results suggest a hydrocarbon-independent reduction of NOx takes place on the iron center, and oxidation of CO is assisted by the palladium ion. The catalytic activity toward HC CO, and NOx removal was studied with simulated and real engine exhaust in the laboratory and on an engine, respectively. Engine test results demonstrate a reduction of NOx of up to 10 percent at catalyst inlet temperatures in the range of 260°C to 280°C. In this paper, possible NOx reduction pathways are also discussed.

In response to global climate change, there is a widespread push to reduce carbon emissions in the transportation sector. For the difficult to decarbonize heavy-duty (HD) vehicle sector, lower carbon intensity fuels can offer a low-cost, near-term solution for CO2 reduction. The use of natural gas can provide such an alternative for HD vehicles while the increasing availability of renewable natural gas affords the opportunity for much deeper reductions in net-CO2 emissions. With this in consideration, the US National Renewable Energy Laboratory launched the Natural Gas Vehicle Research and Development Project to stimulate advancements in technology and availability of natural gas vehicles. As part of this program, Southwest Research Institute developed a hybrid-electric medium-HD vehicle (class 6) to demonstrate a substantial CO2 reduction over the baseline diesel vehicle and ultra-low NOx emissions.

A typical automotive catalytic converter is constructed with a ceramic substrate and a steel shell. Due to a mismatch in coefficients of thermal expansion, the steel shell will expand away from the ceramic substrate at high temperatures. The gap between the substrate and shell is usually filled with a fiber composite material referred to as “mat.” Mat materials are compressed during assembly and must maintain an adequate pressure around the substrate under extreme temperature conditions. The container deformation measurement procedure is used to determine catalytic converter shell expansion during and after a period of hot catalytic converter operation. This procedure is useful in determining the potential physical durability of a catalytic converter system, and involves measuring converter shell expansion as a function of inlet temperature. A post-test dimensional measurement is used to determine permanent container deformation.

This paper describes the findings of a laboratory effort to demonstrate improved automotive exhaust emission control with a cold-start hydrocarbon collection system. The emission control strategy developed in this study incorporated a zeolite molecular sieve in the exhaust system to collect cold-start hydrocarbons for subsequent release to an active catalytic converter. A prototype emission control system was designed and tested on a gasoline-fueled vehicle. Continuous raw exhaust emission measurements upstream and downstream of the zeolite molecular sieve revealed collection, storage, and release of cold-start hydrocarbons. Federal Test Procedure (FTP) emission results show a 35 percent reduction in hydrocarbons emitted during the cold-transient segment (Bag 1) due to adsorption by the zeolite.

This paper describes a distributed digital process control computer designed for large industrial processing plants that has been applied successfully to laboratory engine testing. Over the past two years several complete systems have been installed and adapted to control engines from 75 kW to over 1800 kW with various dynamometer/generator absorption devices. Control problems encountered, and solutions we have found, are discussed along with the wide range of capabilities this type of system can provide. A short comparison is made between distributed digital control systems and mini-computers, listing advantages and disadvantages of both.

The principles of the magnetic-perturbation method of flaw detection and the Barkhausen noise residual stress measurement method are briefly reviewed. It is suggested that they provide very powerful tools for assuring improved ball bearing performance. The methods are applied for the evaluation of ball bearing races. Typical experimental results are presented along with metallurgical sectioning correlation.