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Technical Paper

A Finite Element Modeling Approach for Stability Analysis of Partially Filled Tanker Trucks

The rollover threshold for a partially filled tanker truck carrying fluid cargo is of great importance due to the catastrophic nature of accidents involving such vehicles, particularly when payloads are toxic and flammable. In this paper, a method for determining the threshold of rollover stability of a specific tanker truck is presented using finite element analysis methods.
Technical Paper

Quantification of Yard Hostler Activity and the Development of a Representative Yard Hostler Cycle

Yard hostlers are tractors (switchers) used to move containers at ports and storage facilities. While many speed-time driving cycles for assessing emissions and performance from heavy-duty vehicles exist, a driving cycle representative of yard hostler activity at Port of Long Beach, CA was not available. Activity data were collected from in-use yard hostlers as they performed ship loading/unloading, rail loading/unloading and other yard routines, primarily moving containers on trailers or carts. The activity data were then used to develop four speed-time driving cycles with durations of 1200 seconds, representing light and heavy ship activities and light and heavy load rail activities. These cycles were constructed using actual speed-time data collected during activity logging and the cycles created were statistically comparable to each subset of activity data.
Technical Paper

An Emission and Performance Comparison of the Natural Gas Cummins Westport Inc. C-Gas Plus Versus Diesel in Heavy-Duty Trucks

Cummins Westport Inc. (CWI) released for production the latest version of its C8.3G natural gas engine, the C Gas Plus, in July 2001. This engine has increased ratings for horsepower and torque, a full-authority engine controller, wide tolerance to natural gas fuel (the minimum methane number is 65), and improved diagnostics capability. The C Gas Plus also meets the California Air Resources Board optional low-NOx (2.0 g/bhp-h) emission standard for automotive and urban buses. Two pre-production C Gas Plus engines were operated in a Viking Freight fleet for 12 months as part of the U.S. Department of Energy's Fuels Utilization Program. In-use exhaust emissions, fuel economy, and fuel cost were collected and compared with similar 1997 Cummins C8.3 diesel tractors. CWI and the West Virginia University developed an ad-hoc test cycle to simulate the Viking Freight fleet duty cycle from in-service data collected with data loggers.
Technical Paper

An Investigation into the Emissions Reduction Performance of an SCR System Over Two Years' In-Use Heavy-Duty Vehicle Operation

Increasingly stringent oxides of nitrogen (NOx) and particulate matter (PM) regulations worldwide have prompted considerable activity in developing emission control technology to reduce the emissions of these two constituents from heavy-duty diesel engines. NOx has come under particular scrutiny by regulators in the US and in Europe with the promulgation of very stringent regulation by both the US Environmental Protection Agency (EPA) and the European Union (EU). In response, heavy-duty engine manufacturers are considering Selective Catalytic Reduction (SCR) as a potential NOx reduction option. While SCR performance has been well established through engine dynamometer evaluation under laboratory conditions, there exists little data characterizing SCR performance under real-world operating conditions over time. This project evaluated the field performance of ten SCR units installed on heavy-duty Class 8 highway and refuse trucks.
Technical Paper

System Architecture for Cooperative Vehicle-Pedestrian Safety Applications Using DSRC Communication

Pedestrians account for a significant ratio of traffic fatalities; as a result, research on methods of reducing vehicle-pedestrian crashes is of importance. In this paper, we describe a system architecture that allows the use of vehicle-to-pedestrian (V2P) communication as a means of generating situational awareness and eventually predicting hazards and warning drivers and pedestrians. In contrast, vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) communication for safety applications, V2P has not received much attention. One major reason for this lack of attention had been the unavailability of communication mechanisms between pedestrians and vehicles. Recent advances in enabling Wi-Fi and dedicated short range communication (DSRC) based communication using smart-phones is changing this picture. As a result, V2P communication can be considered as a possible solution.
Technical Paper

Regenerative Braking of a 2015 LMP1-H Racing Car

Regenerative braking coupled to small high power density engines are becoming more and more popular in motorsport applications delivering improved performances while increasing similarities and synergies in between road and track applications. Computer aided engineering (CAE) tools integrated with the telemetry data of the car are an important component of the product development. This paper presents the CAE model developed to describe the race track operation of a LMP1-H racing car covering one lap of the Le Mans circuit. The friction and regenerative braking is discussed.
Technical Paper

Investigation of Femur Response to Longitudinal Impact

Longitudinal impact tests were conducted on the knees of four seated embalmed cadavers using an impact pendulum. Impact force and femur strain histories were recorded, and peak force at fracture was determined. The results show that femur stiffness (average = 3.29 MN) for impacts is nearly the same as for static loads. Peak fracture loads varied from 8731-11570 N, all above the fracture criterion proposed by King, Fan and Vargovick. Strain histories and fracture patterns suggest that bending effects play a major role in determining the response of embalmed cadaver femurs to longitudinal impact.
Technical Paper

Development of Continuous Dilution Factor for CVS Emissions Sampling and Calculation

During the last three decades, the emissions measurement system for heavy duty vehicle testing has employed a Constant Volume Sampler (CVS) system to continuously measure the pollutant concentrations in the dilution tunnel. Subsequent gaseous emissions calculation methods were based on Code of Federal Regulations, Title 40 (CFR-40) in which a formula for calculating dilution factor (DF) was specified to account for background pollutants. However, it is recognized that due to the mechanism of the CVS system, the dilution factor varies from a constant during a test cycle. The DF calculation technique can introduce error in the emissions data, but the magnitude of potential error is small relative to the current emissions standards. However, as the engine technologies improve and cleaner burning fuels are adopted in the near future, the pollutant concentrations from engines will approach those in ambient air.
Technical Paper

Cadaver Femur Responses to Longitudinal Impacts

Results from longitudinal impact tests on the knees of nine seated cadavers are reported. Typical impact velocities, impact force histories and femur strain histories are presented. The importance of femur bending is revealed by strain readings on the medial, lateral, anterior and posterior surfaces. The effects of impactor padding, leg tissue and oblique impacts are illustrated. The average fracture force level was found to be 10.04 kN and the impact energy to be 549J. The fracture patterns and possible mechanisms are discussed.
Technical Paper

Alternative Fuel Truck Evaluation Project - Design and Preliminary Results

The objective of this project, which is supported by the U.S. Department of Energy (DOE) through the National Renewable Energy Laboratory (NREL), is to provide a comprehensive comparison of heavy-duty trucks operating on alternative fuels and diesel fuel. Data collection from up to eight sites is planned. This paper summarizes the design of the project and early results from the first two sites. Data collection is planned for operations, maintenance, truck system descriptions, emissions, duty cycle, safety incidents, and capital costs and operating costs associated with the use of alternative fuels in trucking.
Journal Article

A Work-Based Window Method for Calculating In-Use Brake-Specific NOx Emissions of Heavy-Duty Diesel Engines

A work-based window method has been developed to calculate in-use brake-specific oxides of nitrogen (NOx) emissions for all engine speeds and engine loads. During an in-use test, engine speed and engine torque are read from the engine's electronic control unit, and along with time, are used to determine instantaneous engine power. Instantaneous work is calculated using this power and the time differential in the data collection. Work is then summed until the target amount of work is accumulated. The emissions levels are then calculated for that window of work. It was determined that a work window equal to the theoretical Federal Test Procedure (FTP) cycle work best provides a means of comparison to the FTP certification standard. Also, a failure criterion has been established based on the average amount of power generated in the work window and the amount of time required to achieve the target work window to determine if a particular work window is valid.