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Hybrid electric vehicles (HEVs) are worldwide recognized as one of the best and most immediate opportunities to solve the problems of fuel consumption, pollutant emissions and fossil fuels depletion, thanks to the high reliability of engines and the high efficiencies of motors. Moreover, as transport policy is becoming day by day stricter all over the world, moving people or goods efficiently and cheaply is the goal that all the main automobile manufacturers are trying to reach. In this context, the municipalities are performing their own action plans for public transport and the efforts in realizing high efficiency hybrid electric buses, could be supported by the local policies. For these reasons, the authors intend to propose an efficient control strategy for a hybrid electric bus, with a series architecture for the power-train.

This paper is a summary of the aerodynamic development of the 1988 Chevrolet and GMC pickup truck. Comprehensive drag reduction work was performed with clay models from the original concept through the detailed full-scale model. In addition, the aerodynamic development included wind rush noise reduction, optimization of engine cooling air flow, and body surface pressures for HVAC performance.

Two new 4 X 4 drivetrain systems have been developed for highway tractors that are used to pull multiple trailer combinations. The first one is a 4 X 2 that automatically becomes a 4 X 4 when conditions exist that require 4 X 4 operation. The second one is a full-time 4 X 4 that proportions the drive torque 36% to the front axle and 64% to the rear axle. A unique front driving steering axle has also been developed that permits a 4 X 4 system to be installed in a standard 4 X 2 truck. There is no need to relocate any major components to make space available for a front driving steering axle.

Various drag reduction strategies have been applied to a full size production pickup truck to evaluate their effectiveness by using Computational Fluid Dynamics (CFD). The drag reduction devices evaluated in this study were placed at the rear end of the truck bed and the tailgate. Three types of devices were evaluated: (1) boat tail-like extended plates attached to the tailgate; (2) mid-plate attached to the mid-section of the tailgate and; (3) flat plates partially covering the truck bed. The effect of drag reduction by various combinations of these three devices are presented in this paper. Twenty-four configurations were evaluated in the study with the best achievable drag reduction of around 21 counts (ΔCd = 0.021). A detailed breakdown of the pressure differentials at the base of the truck is provided in order to understand the flow mechanism for the drag reductions.

In the recent years, Electric-mobility has been a trending aspect in the transportation sector. Increase in the air pollution by the use of combustion vehicles resulted in the initiation of various subsidiaries and norms by the governments across the world. To bring an eco-friendly transportation, many cities across the world are trying to incorporate the electric vehicles in the public transportation system. In India, State Road Transport Undertakings (SRTU’s) have started adopting electric buses. One of the critical requirement for successful operation of electric vehicles is charging infrastructure, which is required for charging the vehicles. There are various charging technologies available in the industry. This paper presents a case study for evaluating pantograph based electric bus charging systems for Patna project and compares the charging schedule, charger infrastructure sizing, CAPEX and OPEX with respect to traditional proven CCS2 charging technology.

To date, no definitive work to quantify and compare the braking rating horsepower relationships between vehicles equipped with brake assemblies containing asbestos, non-asbestos, and semi-metallic friction material has been completed. This paper will report the results of a brake fade evaluation performed on a 34,000-lb. GVW vehicle in accordance with SAE J880 Brake System Rating Test Code Procedures and has quantified braking horsepower, fade temperature resistance, thermal response temperature rise, lining wear, and drum wear.

Comparison studies have been conducted on a 1:16th scale model and a full scale tractor trailer of a variety of sealed aft cavity devices as a means to develop or enhance commercial drag reduction technology for class 8 vehicles. Various base cavity geometries with pressure taps were created for the scale model. The studies confirmed that length has an important effect on performance. The interaction of the boat-tailed aft cavity with other drag reduction devices, specifically side skirts, was investigated with results showing no discernable drag performance interaction between them. Overall, the experiments show that a boat-tailed aft cavity can reduce the drag up to 13%. Full-scale tests of a commercially derived product based on these scale tests were also completed using SAE Type II testing procedures. Full-scale tests indicated a fuel savings of over 6.5%.

Regulatory requirements in the European Union (EU) for off-road machines and road vehicles are different. Vehicles which transport passengers and goods, along with attached trailers, as well as road motorcycles must meet EEC type-approval requirements. All other types of self-propelled machines must meet the requirements of the Machinery Directive (Council Directive 98/37/EC), and the Electromagnetic Compatibility (EMC) Directive (Council Directive 89/336/EEC) and possibly other directives. This includes such categories as agriculture and forestry machines, construction machines, industrial trucks and similar products. The various directives outline the different processes for demonstrating compliance with the EU requirements. The intent of this paper is to summarize a few of the requirements that are of interest to off-highway equipment manufacturers and to identify some sources of information about the regulatory requirements.

“Today, wearing parts are regularly subjected to abnormal loading conditions. They must be able to accept these conditions without failure. In continuous operations, unscheduled downtime greatly increases maintenance costs, not to mention the cost of lost production. White iron castings offer premium abrasion resistance for many of these applications, but are often not used due to the possibility of brittle failure and the difficulty of mechanical attachment. This paper discusses the properties and applications of a composite of martensitic white iron and mild steel. This laminate will accept medium to high impact without loss of service failure, and can be installed by mechanical means or with welded attachment.”

A computer simulation was developed to investigate the effect of wind on test track estimation of heavy truck fuel efficiency. Monte Carlo simulations were run for various wind conditions, both with and without gusts, and for two different vehicle aerodynamic configurations. The vehicle configurations chosen for this study are representative of typical Class 8 tractor trailers and use wind tunnel measured drag polars for performance computations. The baseline (control) case is representative of a modern streamlined tractor and conventional trailer. The comparison (test) case is the baseline case with the addition of a trailer drag reduction device (trailer skirt). The integrated drag coefficient, overall required power, total fuel consumption, and average rate of fuel consumption were calculated for a heavy truck on an oval test track to show the effect of wind on test results.

A Computer Aided System (CAS) is developed in order to evaluate off-road wheeled vehicle mobility. The system takes into consideration both vehicle technical parameters and the main specifications of the soil on which the vehicle is expected to operate. Thirty seven vehicle technical parameters organized in nine groups are considered. These groups are: weights, engine parameters, dimensions, performance, transmission, steering, brakes, tires, and self recovery means. The main soil specifications of the soil considered are the soil type (clay, silt, or sand) and the shear and bearing resistance represented by the cone index or the gradient cone index. The evaluation process depends on considering a datum value for each vehicle technical parameter. These datum values or norms are obtained from a statistical analysis study of the technical parameters for a sample of 155 off-road wheeled vehicles representing different schools from all over the world [1].

Truck platooning is an emerging technology that exploits the drag reduction experienced by bluff bodies moving together in close longitudinal proximity. The drag-reduction phenomenon is produced via two mechanisms: wake-effect drag reduction from leading vehicles, whereby a following vehicle operates in a region of lower apparent wind speed, thus reducing its drag; and base-drag reduction from following vehicles, whereby the high-pressure field forward of a closely-following vehicle will increase the base pressure of a leading vehicle, thus reducing its drag. This paper presents a physics-guided empirical model for calculating the drag-reduction benefits from truck platooning. The model provides a general framework from which the drag reduction of any vehicle in a heterogeneous truck platoon can be calculated, based on its isolated-vehicle drag-coefficient performance and limited geometric considerations.

Planning for charging in transport missions is vital when commercial long-haul vehicles are to be electrified. In this planning, accurate range prediction is essential so the trucks reach their destinations as planned. The rolling resistance significantly influences truck energy consumption, often considered a simple constant or a function of vehicle speed only. This is, however, a gross simplification, especially as the tire temperature has a significant impact. At 80 km/h, a cold tire can have three times higher rolling resistance than a warm tire. A temperature-dependent rolling resistance model is proposed. The model is based on thermal networks for the temperature at four places around the tire. The model is tuned and validated using rolling resistance, tire shoulder, and tire apex temperature measurements with a truck in a climate wind tunnel with ambient temperatures ranging from -30 to 25 °C at an 80 km/h constant speed.

The Nexus vehicle was designed and built for Transport Canada at the University of Saskatchewan to demonstrate that a safety compliant single passenger commuter vehicle could attain extremely low fuel consumption rates at modest highway speeds. Experimentally determined steady state fuel consumption rates of the Nexus prototype ranged from 1.6 L/100 km at 61 km/hr up to 2.8 L/100 km at 121 km/hr. Fuel consumption rates for the Society of Automotive Engineers (SAE) driving cycle tests were 4.5 L/100 km for the SAE Urban cycle and 2.0 L/100 km for the SAE Interstate 55 cycle. The efficiency of the power train was determined using a laboratory dynamometer, enabling the road test results to be compared to the results from an energy and performance simulation program. Predicted fuel economy was in good agreement with that determined experimentally. Widespread use of single passenger commuter vehicles would substantially reduce current transportation energy consumption.

This paper outlines the techniques used to install both a full scale and a half scale tractor-trailer model in the 9×9 meter National Research Council of Canada wind tunnel in Ottawa, Canada. The objectives were to measure the cooling drag of an active cooling system and to investigate the aerodynamic testing limits of long, yawed models inside a solid wall wind tunnel. The tunnel interference problem is discussed as it pertains to the upstream boundary, test section floor, downstream boundary, ceiling and side walls and tractor-trailer surface pressure measurements. A potential solution to the problem, however, is the subject of a follow-up paper.

Edinburgh is one of the fastest growing and most prosperous cities in the United Kingdom. This success has brought with it the problems of traffic congestion and pollution. The Edinburgh Metro would use the city's disused railway heritage combined with modern light rail technology to provide a popular and sustainable transport system. When this proposal was originally submitted in 1999, it seemed a worthwhile but distant possibility. However, in October 2001 and March 2002, the Scottish Executive announced preliminary funding packages that mean that significant progress is now likely. The planned system could be operating by 2009.

The traditional approach to materials selection is to compare the results of direct substitution of alternative materials on an individual part-by-part basis. The engineer then frequently faces so many design constraints that use of a new material is infeasible. This approach also precludes redesign to optimize the characteristics of new materials. A methodology is presented which facilitates the consideration of a large system comprised of many components. The management science technique of “multi-attribute utility analysis” is applied as a tool for use by automotive design engineers. Attributes include capital cost, piece cost, weight, design flexibility and corrosion resistance. The results serve as a decision making tool to determine which design provides the greatest overall value. Also, the results may be used as a design aid to quantify desirable tradeoffs between attributes, thus pointing the way towards optimal redesign.

The underbody of a truck is responsible for an appreciable portion of the vehicle’s aerodynamic drag, and thus its fuel consumption. A better understanding of the underbody aerodynamics could lead to designs that are more environmentally friendly. Unfortunately there are difficulties with correctly replicating the ground condition and rotating wheels when using the classical approach of a wind-tunnel for aerodynamic investigation. This in turn leads to computational modelling problems. A lack of experimental data for Computational Fluid Dynamics (CFD) validation means that the flow field in this area has seldom been investigated. There is thus very little information available for the optimisation and design of underbody aerodynamic devices. This paper investigates the use of a water-towing tank, which allows the establishment of the correct near-ground flow while permitting good optical access. Using a 1/10 scale model, Reynolds Numbers of around 0.7 million are achieved.

Highway and roadway surface measurement is a practice that has been ongoing for decades now. This sort of measurement is intended to ensure a safe level of road perturbances. The measurement may be conducted by a slow moving apparatus directly measuring the elevation of the road, at varying distance intervals, to obtain a road profile, with varying degrees of resolution. An alternate means is to measure the surface roughness at highway speeds using accelerometers coupled with high speed distance measurements, such as laser sensors. Vehicles out rigged with such a system are termed inertial profilers. This type of inertial measurement provides a sort of filtered roadway profile. Much research has been conducted on the analysis of highway roughness, and the associated metrics involved. In many instances, it is desirable to maintain an off-road course such that the course will provide sufficient challenges to a vehicle during durability testing.

A wide variety of computer and communications technology vendors currently in the marketplace offer technologies, products and services designed to streamline regulatory processes and improve operational efficiency for trucking companies. The goods and services are sold based on their “functional attributes” and the cost is a direct function of the nature of the application and the carrier's needs. The Federal Highway Administration (FHWA) Intelligent Transportation Systems/Commercial Vehicle Operations (ITS/CVO) User Services are “bundles” of functional services envisioned by the FHWA to help advance the overall objectives of improved operational efficiency of our nation's roadways and servicing of the commercial vehicle population. Because many of the technology applications are still in the development stage, a framework has been developed to assess the future hypothetical benefits and costs of the ITS/CVO User Services Program.