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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 addresses fuel economy standards that can be obtained in 1985 for two-wheel drive LDT's using existing technology. To estimate the fuel economy, the fleet of LDT's is first segmented into market classes based on the concept of utility. The 1985 sales share of each class is predicted from an extrapolation of current trends as well as published sales forecasts. The 1985 fuel economy of each market class is projected using 1) MY '80 truck technology and fuel economy as a baseline, 2) a regression equation that allows an estimate of fuel economy based on the weight, drag, and engine displacement, and 3) the addition of fuel-efficient technologies. Estimates of weight reduction and new model introduction within each market class were derived from published manufacturers' plans. Based on this methodology, this analysis concludes that a fleet fuel economy in excess of 24/25 mpg is feasible for 1985 without/with the use of diesel engines.

The work presented here seeks to compare different means of providing scavenging systems for an automotive 2-stroke engine. It follows on from previous work solely investigating uniflow scavenging systems, and aims to provide context for the results discovered there as well as to assess the benefits of a new scavenging system: the reverse-uniflow sleeve-valve. For the study the general performance of the engine was taken to be suitable to power a medium-duty truck, and all of the concepts discussed here were compared in terms of indicated fuel consumption for the same cylinder swept volume using a one-dimensional engine simulation package. In order to investigate the sleeve-valve designs layout drawings and analysis of the Rolls-Royce Crecy-type sleeve had to be undertaken.

NAIPC reflects modern developments in alternative, electrified propulsion systems, high tech gasoline, diesel ICEs, hydrogen fuel cells, battery electric systems, variable transmissions.

Due to the general requirements in the automotive industry to reduce the power consumption, fuel consumption rate and CO2 emission a new HID (High Intensity Discharge) bulb with only 25W is under development for front lighting systems. A first headlamp integrated in a hybrid vehicle is now launched as a first application in the market. The current regulation in ECE allows to get rid of the mandatory headlamp cleaning system and the automatic leveling requirement once the 25W HID bulb is applied. The reason for this is the objective luminous flux of the 25W HID bulb, which emits less than 2000 lm, a boundary defined in the regulation, where a headlamp cleaning and an automatic leveling is requested. That simplifies especially the integration in smaller vehicles and electric and hybrid vehicles. The paper describes the special design of the headlamp, the projector unit, the light performance, packaging advantages and future outlook of further applications in the near future.

Manufacturers of heavy-duty diesel engines are facing increasingly stringent, emission standards. These standards have motivated new research efforts towards improving the performance of diesel engines. The objective of the present program is to develop a comprehensive analytical model of the diesel combustion process that can be used to explore the influence of design changes. This will enable industry to predict the effect of these changes on engine performance and emissions. A major benefit of the successful implementation of such models is that engine development time and costs would be reduced through their use. The computer model is based on the three-dimensional KIVA-II code, with state-of-the-art submodels for spray atomization, drop breakup / coalescence, multi-component fuel vaporization, spray/wall interaction, ignition and combustion, wall heat transfer, unburned HC and NOx formation, and soot and radiation.

Abstract Due to the increasing requirements for efficiency, the wide range of characteristics and the improved possibilities of modern development and production processes, compressors in turbochargers have become more individualized in order to adapt to the requirements of internal combustion engines. An understanding of the working mechanisms as well as an understanding of the way that losses occur in the flow allows a reduced development effort during the optimization process. This article presents three-dimensional (3D) Computational Fluid Dynamics (CFD) investigations of the loss mechanisms and quantitative calculations of individual losses. The 3D-CFD method used in this article will reduce the drawbacks of one-dimensional calculation as far as possible. For example, the twist of the blades is taken into account and the “discrete” method is used for loss calculation instead of the “average” method.

The legislations on emission reduction is getting stringent everywhere in the world. India is following the same trend, with Government of India (GOI) declaring the nationwide implementation of BS 6 legislation by April 2020 and Real Driving Emission (RDE) Cycle relevant legislation by 2023. Additionally GOI is focusing on reduction of CO2 emissions by introduction of stringent fleet CO2 targets through CAFE regulation, making it mandatory for vehicle manufacturers to simultaneously work on gaseous emissions and CO2 emissions. Simultaneous NOx emission reduction and CO2 reduction measures are divergent in nature, but with a 48 V Diesel hybrid, this goal can be achieved. The study presented here involves arriving at the right future hybrid-powertrain layout for a Sports Utility Vehicle (SUV) in the Indian scenario to meet the future BS 6 and CAFÉ legislations. Diesel engines dominate the current LCV and SUV segments in India and the same trend can be expected to continue in future.

Abstract Regulations limiting GreenHouse Gases (GHG) from Heavy-Duty (HD) commercial vehicles in the United States (US) and European Union will phase in between the 2024 and 2030 model years. These mandates require efficiency improvements at both the engine and vehicle levels, with the most stringent reductions required in the heaviest vehicles used for long-haul applications. At the same time, a 90% reduction in oxides of nitrogen (NOx) will be required as part of new regulations from the California Air Resources Board. Any technologies applied to improve engine efficiency must therefore not come at the expense of increased NOx emissions. Research into advanced engine architectures and components has identified improved turbomachine efficiency as one of the largest potential contributors to engine efficiency improvement. However this comes at the cost of a reduced capability to drive high-pressure Exhaust Gas Recirculation (EGR).

Diesel injection equipment is required to be more accurate and higher in pressure to meet the increasingly strict emission, fuel consumption regulations and higher engine performance. It also needs to achieve a number of requirements such as robustness against diversified market fuels, easy installation to engine, etc.

The AVL International Commercial Powertrain Conference is the premier forum for truck, agricultural and construction equipment manufacturers to discuss powertrain technology challenges and solutions across their industries. The topics of the conference, which happens every two years, cover all five elements of a modern powertrain: engine, transmission, electric motor, battery and the electronic control which are used basically the same way in the quest for optimal efficiency and environmental compatibility. This event offers a unique opportunity for highly regarded professionals to address the synergy effects and distinctive characteristics of commercial vehicles, agricultural tractors and non-road vehicles, and industrial machinery. These proceedings are being co-published with SAE International, via a strategic partnership.

By means of computer simulation, the potential of a Band Variable-Inertia Flywheel (BVIF) as an energy storage device for a diesel engine city bus is evaluated. Replacing both a fixed-inertia flywheel (FIF) and a continuously variable transmission (CVT), the BVIF is capable of accelerating a vehicle from rest to a nearly-constant speed, while recovering part of the kinetic energy normally dissipated through braking of the vehicle. The results are compared with that of conventionally-powered bus. A fuel saving of up to 30 percent is shown with the BVIF-integrated system. The regenerative braking system reduces brake wear by a factor of five in comparison with the conventional vehicle.

Parameters like brake mean effective pressure, mean velocity of the piston, hardness of the wear surface, oil film thickness, and surface areas of critical wear parts are similar for all the diesel engines. The mean piston velocity at the rated speed is nearly the same for all the diesel engines. The mechanical efficiency normalized to an arbitrary brake mean effective pressure (bmep) is dependent on the size of the engine. The engine life seems to be proportional directly to the square of a characteristic dimension namely, cylinder bore of the engine and inversely to speed and load factor for engines varying widely in sizes and ratings.

With the increase of heavy-duty transportation, more fuel efficient technologies and services have become of great importance due to their environmental and economical impacts for the fleet managers. In this paper, we first develop a new analytical model of the heavy-truck for its dynamics and its fuel consumption, and valid the model with experimental measurements. Then, we propose a bi-level optimization approach to reduce the fuel consumption, thus the CO2 emissions, while ensuring several safety constraints in real-time. Numerical results show that important reduction of the fuel consumption can be achieved, while satisfying imposed safety constraints.

This paper starts with an analysis of design configurations of the drivelines with different power-dividing units (PDUs) of main dump truck manufacturing companies. As it follows from the analysis, improvements of articulated truck energy efficiency and reduction of fuel consumption by optimizing the power distribution to the drive wheels are still open issues. The problem is that a variety of operating and terrain conditions of dump trucks requires different wheel power distributions that cannot be provided by one set of PDUs employed in a truck. The central PDU in the transfer case was identified as the most important PDU among the five PDUs, which plays a crucial role in the power distribution between the front axle and the rear tandem of a 6×6 articulated dump truck. The paper formulates a constraint optimization problem to minimize the tire slippage power losses by optimizing the power distribution between the drive wheels.

A quasi-dimensional computer simulation model is presented to simulate the thermodynamic and chemical processes occurring within a spark ignition engine during compression, combustion and expansion based upon the laws of thermodynamics and the theory of equilibrium. A two-zone combustion model, with a spherically expanding flame front originating from the spark location, is applied. The flame speed is calculated by the application of a turbulent entrainment propagation model. A simplified theory for the prediction of in-cylinder charge motion is proposed which calculates the mean turbulence intensity and scale at any time during the closed cycle. It is then used to describe both heat transfer and turbulent flame propagation. The model has been designed specifically for the two-stroke cycle engine and facilitates seven of the most common combustion chamber geometries. The fundamental theory is nevertheless applicable to any four-stroke cycle engine.

To meet future needs for heavy truck cooling, a novel high performance radial compact cooling system (CCS) was developed. Measurements with a prototype system were conducted in a component wind tunnel and with truck-installed systems in a climatic vehicular wind tunnel. The CSS is compared to conventional axial and side-by-side systems. In comparison with a conventional axial system, the performance per unit volume of the CCS is 42% higher, the noise level is about 6 dB lower and the power consumption of the radial fan is 70% of the axial fan leading to significant savings in fuel consumption.

In the truck industry there is a continuous demand to increase the efficiency and to decrease the emissions. To acknowledge both these issues a waste heat recovery system (WHR) is combined with a partially premixed combustion (PPC) engine to deliver an efficient engine system. Over the past decades numerous attempts to increase the thermal efficiency of the diesel engine has been made. One such attempt is the PPC concept that has demonstrated potential for substantially increased thermal efficiency combined with much reduced emission levels. So far most work on increasing engine efficiency has been focused on improving the thermal efficiency of the engine while WHR, which has an excellent potential for another 1-5 % fuel consumption reduction, has not been researched that much yet. In this paper a WHR system using a Rankine cycle has been developed in a modeling environment using IPSEpro.

Engine mounts are an integral part of the vehicle that helps in reducing the vibrations generated from the engine. Engine mounts require a simple yet complicated amalgamation of two very different materials, steel and rubber. Proper adhesion between the two is required to prevent any part failure. Therefore, it becomes important that a comprehensive study is done to understand the mating phenomenon of both. A good linking between rubber and metal substrate is governed by surface pretreatment. Various methodologies such as mechanical and chemical are adopted for the same. This paper aims to present a comparative study as to which surface pretreatment has an edge over other techniques in terms of separation force required to break the bonding between the two parts. The study also presents a cost comparison between the techniques so that the best possible technique can be put to use in the commercial vehicle industry.

In order to reduce fuel consumption, companies have been looking at hybridizing vehicles. So far, two main hybridization options have been considered: electric and hydraulic hybrids. Because of light duty vehicle operating conditions and the high energy density of batteries, electric hybrids are being widely used for cars. However, companies are still evaluating both hybridization options for medium and heavy duty vehicles. Trucks generally demand very large regenerative power and frequent stop-and-go. In that situation, hydraulic systems could offer an advantage over electric drive systems because the hydraulic motor and accumulator can handle high power with small volume capacity. This study compares the fuel displacement of class 6 trucks using a hydraulic system compared to conventional and hybrid electric vehicles. The paper will describe the component technology and sizes of each powertrain as well as their overall vehicle level control strategies.