[en] In this paper, we study the effect of moving bottlenecks on traffic flow. The full velocity difference (FVD) model is extended to the traffic flow on a two-lane highway, and new lane changing rule is proposed to reproduce the vehicular lane changing behavior. Using this model, we derive the fundamental current—density diagrams for the traffic flow with the effect of moving bottleneck. Moreover, typical time—space diagram for a two-lane highway shows the formation and dissipation of a moving bottleneck. Results demonstrate that the effect of moving bottleneck enlarges with the increase of traffic density, but the effect can be reduced by increasing the maximum velocity of heavy truck. The effects of multiple moving bottlenecks under different conditions are investigated. The effect becomes more remarkable when the coupling effect of multiple moving bottlenecks occurs. (interdisciplinary physics and related areas of science and technology)

[en] For several years, Sandia National Laboratories and Lawrence Livermore National Laboratory have been part of a consortium funded by the Department of Energy to improve fuel efficiency of heavy vehicles such as Class 8 trucks through aerodynamic drag reduction. The objective of this work is to demonstrate the feasibility of using the steady Reynolds-Averaged Navier-Stokes (RANS) approach to predict the flow field around heavy vehicles, with special emphasis on the base region of the trailer, and to compute the aerodynamic forces. In particular, Sandia's computational fluid dynamics code, SACCARA, was used to simulate the flow on a simplified model of a tractor-trailer vehicle. The results are presented and compared with NASA Ames experimental data to assess the predictive capability of RANS to model the flow field and predict the aerodynamic forces

[en] The tractive power of KZC-5 rear dump truck in underground mine is studied in this paper. The principles and ways of defining the power are discussed. It is proved that the power of KZC-5 rear dump truck in underground mine is reasonable in the industrial scale test

[en] Weigh-in-motion (WIM) systems are used for identifying the dynamic force exerted on the ground by axles of a vehicle. These systems are important for monitoring the gross vehicle weight and the vehicle axle load. Overweighted trucks on the roads increase pavement damage and traffic accidents. Knowing the accuracy of WIM systems is necessary. In the case of liquid transport the ‘sloshing effect’ affects this accuracy. This paper aims to analyze the dynamic measurement of the axle forces in vehicles carrying liquid during WIM up to 6 km h"−"1. Laboratory experiments using one vehicle with six axles and liquid loads on different levels in weighing instruments are presented. A non-linear computational multi-mass-springs model was developed and laboratory experiments were carried out to show the acceleration influences on axle forces of vehicles with six axles and with and without baffles to vary the ‘sloshing effect’. (paper)

[en] Since 1975, the Corporate Average Fuel Economy (CAFE) program has been the main policy tool in the US for coping with the problems of increasing fuel consumption and dependence on imported oil. The program mandates average fuel economy requirements for the new vehicle sales of each manufacturer's fleet, with separate standards for cars and light trucks. The fact that each manufacturer must on its own meet the standards means that the incentives to improve fuel economy are different across manufacturers and vehicle types, although the problems associated with fuel consumption do not make such distinctions. This paper evaluates different mechanisms to offer automakers the flexibility of joint compliance with nationwide fuel economy goals: tradable CAFE credits, feebates, output-rebated fees, and tradable credits with banking. The policies are compared according to the short- and long-run economic incentives, as well as to issues of transparency, implementation, administrative and transaction costs, and uncertainty

[en] The OHVT Technology Roadmap for 2000 presents the multiyear program plan of the U.S. DOE's Office of Heavy Vehicle Technologies (OHVT). It is an update of the 1997 plan, reflecting changes in regulations and ongoing discussions with DOE's heavy vehicle customers. The technical plan covers three classes of trucks: (1) class 7-8 (large, on-highway trucks); (2) class 3-6 (medium duty trucks); (3) class 1-2 (pickups, vans, and sport utility vehicles) as well as enabling and supporting technologies. The Roadmap documents program goals, schedules, and milestones

[en] A methodology was developed for automated assessment of the reliability of the process of sheet metal forming process to reduce the defects in complex components manufacture. The article identifies the range of allowable values of the stamp parameters to obtain defect-free punching of spars trucks. (paper)

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