Alternative Fuels and Advanced Vehicle Technologies for Improved Environmental Performance

Towards Zero Carbon Transportation

Richard Folkson

• Verlag: Woodhead Publishing
• Jahr: 2014
• ISBN:
  9780857097422
• Thema: Tecnología e ingeniería
• Thema: Ingeniería química y bioquímica

Most vehicles run on fossil fuels, and this presents a major emissions problem as demand for fuel continues to increase. Alternative Fuels and Advanced Vehicle Technologies gives an overview of key developments in advanced fuels and vehicle technologies to improve the energy efficiency and environmental impact of the automotive sector.

Part I considers the role of alternative fuels such as electricity, alcohol, and hydrogen fuel cells, as well as advanced additives and oils, in environmentally sustainable transport. Part II explores methods of revising engine and vehicle design to improve environmental performance and fuel economy. It contains chapters on improvements in design, aerodynamics, combustion, and transmission. Finally, Part III outlines developments in electric and hybrid vehicle technologies, and provides an overview of the benefits and limitations of these vehicles in terms of their environmental impact, safety, cost, and design practicalities.

Alternative Fuels and Advanced Vehicle Technologies is a standard reference for professionals, engineers, and researchers in the automotive sector, as well as vehicle manufacturers, fuel system developers, and academics with an interest in this field.

• Provides a broad-ranging review of recent research into advanced fuels and vehicle technologies that will be instrumental in improving the energy efficiency and environmental impact of the automotive sector
• Reviews the development of alternative fuels, more efficient engines, and powertrain technologies, as well as hybrid and electric vehicle technologies

1

Introduction

R. Folkson, University of Hertfordshire, UK

Abstract:

There are very many different technology alternatives available to deliver sustainable vehicles with low carbon emissions. This chapter reviews available methods and the use of technology road-mapping to plan for future adoption by manufacturers. Vehicle technology contributions to carbon reductions are considered together with the role of powertrains in the challenge. Regulatory requirements and consumer trends including the role of traffic management are discussed. There is a review of global manufacturing and mass production issues affecting scale. Commercial vehicle and bus issues are compared with car technology. The increasing role of electrification is discussed including sources of electricity. Current sales statistics and volumes are reviewed with forecasts for the future including a longer term vision.

Key words

low carbon emissions

technology road-mapping

powertrain

regulations

traffic management

global manufacturing

electrification

sales forecasts

1.1 Introduction

There are very many different alternative technologies available for manufacturer to deliver sustainable vehicles with low carbon emissions. This chapter will review all of the major alternatives available, which will be described in greater detail in subsequent chapters. This section is intended as an overview of all the alternatives, how these are likely to be adopted by manufacturers and consumers and the longer term vision for where the industry is likely to be going.

Technologies that are considered to deliver sustainable vehicles with low emissions include the following:

• internal combustion engines – including downsizing and new combustion technology

• hybrids

• battery electric drives

• flywheel stored energy

• bio-fuels

• synthetic fuels

• gaseous fuels

• hydrogen

• fuel cells.

Each technology will be discussed in detail including vehicle and powertrain effects, affordability and consumer acceptance issues.

1.2 Technology roadmaps to deliver low carbon targets

Manufacturers and government agencies use technology roadmaps to assist in identifying major areas for the development of new technologies. An example of a current roadmap was developed by the Automotive Council UK in 2010 and can be reviewed at Automotive Council UK (2010).

The principle areas of development identified in the roadmap were:

• internal combustion engines

• electric machines and power electronics

• lightweight vehicle and powertrain structures

• intelligent transport systems

• energy storage and energy management.

The benefit of roadmapping is that it provides guidance to manufacturers and government agencies on major areas that are considered priorities for future research and investment projects. The roadmap contains the vision statement that ‘Individual manufacturers will prioritise certain technologies to fit with brand values, but oEMs share a common view of a high level technology roadmap’. All of the technologies shown in the roadmap are reviewed in later chapters of this book. The principal technologies in the roadmap are shown in Fig. 1.1. Technologies to reduce carbon emissions can be split into two major areas – vehicle technology and powertrain technology – which are discussed in the next two sections.

1.1 Technology roadmap. (Source: Automotive Council UK, based on an independent report ‘New Automotive Innovation and Growth Team’ (NAIGT); http://www.automotivecouncil.co.uk/wp-content/uploads/2010/12/Tech-Road-Maps-RD-Capability-Final.pdf)

1.3 Vehicle technology contributions to low carbon targets

Vehicle technologies are those associated with all areas of the vehicle other than the propulsion system (or powertrain). These are generally focused on reducing energy losses that result from moving the vehicle along a road and through the air. The major aspects of vehicle technology that offer potential energy savings are:

• weight reduction

• aerodynamic drag reduction

• rolling resistance and friction improvements.

Weight reduction is a key element of reduced energy simply due to Newton’s law:

$\mathrm{Force}=\mathrm{Mass}\times \mathrm{Acceleration}$

The higher the mass, the more force, and therefore energy, is required to accelerate the vehicle. Mass also plays an important role in friction as it is directly proportional to the rolling resistance of the vehicle. so weight is the enemy and all measures that can reduce it are beneficial for energy use efficiency.

Manufacturers are therefore increasingly using lighter weight materials that include:

• high strength steels

• aluminium and magnesium alloys

• engineering plastics

• fibre reinforced plastics including carbon fibre.

High strength and alloy steels such as boron steel are used to reduce material thickness but retain strength in highly stressed components such as door pillars in the area of side impact protection. These are frequently joined to lower strength steel for less stressed areas by utilising laser welded blanks prior to forming or, more recently, through the application of tailor rolled sections that provide steel sheet which is thicker in high stressed areas and thinner where lower stresses are experienced (Fig. 1.2).

1.2 Tailor rolled boron steel B-pillar.

Aluminium is increasingly used in premium vehicles such as the Jaguar XJ and XK models, Audi A8 and high performance sports cars such as Ferrari and Aston Martin. Manufacturers use several different methods for weight reduction in aluminium and magnesium structures with different joining methods using adhesives or self-piercing rivets, sheet metal forms, extrusions and die-castings. The weight savings offered by aluminium and magnesium are likely to see increasing applications for parts such as closure panels (bonnet/hood, boot lid/trunk and doors) in mass market vehicles as fuel prices rise and legislative pressures force manufacturers to achieve ever improving fuel economy, although thinner gauge high strength steel will continue to be competitive for many applications.

Plastics and composites will continue to be increasingly adopted for weight reduction and major manufacturers such as Ford are investigating how to reduce the cost of carbon composites for high volume applications. The challenge with all weight reduction technologies is to balance the affordability of the new technology, which is generally more expensive than mild steel, against the energy savings over the life of the vehicle and the total cost to the consumer.

Aerodynamic drag reduction is concerned with minimising the forces associated with air resistance as vehicles push air aside during motion. This is characterised by the equation:

$\mathit{F}={\mathit{C}}_{\mathit{D}}\times \mathit{A}$

where F = force, C_D = drag coefficient and A = frontal area of vehicle.

Manufacturers apply much detailed design effort to minimising the drag coefficient by ensuring laminar air flow over the body and reduction of discontinuities which disturb the air flow such as openings, gaps and sharp edges. Actions include lowering frontal body structure to create an air dam, rear spoilers and smooth underbody to achieve laminar flow. There is an increasing use of active aerodynamic aids ...