Llegada de la modernidad (1920-1969)

GLOBAL ENERGY CONSUMPTION DUE TO FRICTION IN PASSENGER CARS

VTT Technical Research Centre of Finland and Argonne National Laboratory

This study presents calculations on the global fuel energy consumption used to overcome friction in passenger cars in terms of friction in the engine, transmission, tires, and brakes. Friction in tribocontacts was estimated according to prevailing contact mechanisms such as elastohydrodynamic, hydrodynamic, mixed, and boundary lubrication. Coefficients of friction in the tribocontacts were estimated based on available information in the literature on the average passenger car in use today, a car with today’s advanced commercial tribological technology, a car with today’s best advanced technology based upon recent research and development, and a car with the best technology forecasted in the next 10 years. The following conclusions were reached:

- In passenger cars, one-third of the fuel energy is used to overcome friction in the engine, transmission, tires, and brakes. The direct frictional losses, with braking friction excluded, are 28% of the fuel energy. In total, 21.5% of the fuel energy is used to move the car.

- Worldwide, 208000 million litres of fuel (gasoline and diesel) was used in 2009 to overcome friction in passenger cars. This equals 360 million tonne oil equivalent per year (Mtoe/a) or 7.3 million TJ/a. Reductions in frictional losses will lead to a threefold improvement in fuel economy as it will reduce both the exhaust and cooling losses also at the same ratio.

- Globally, one passenger car uses on average of 340 l of fuel per year to overcome friction, which would cost 510 euros according to the average European gas price in 2011 and corresponds to an average driving distance of 13000 km/a.

- By taking advantage of new technology for friction reduction in passenger cars, friction losses could be reduced by 18% in the short term (5–10 years) and by 61% in the long term (15–25 years). This would equal worldwide economic savings of 174000 million euros and 576000 million euros, respectively; fuel savings of 117000 million and 385000 million litres, respectively; and CO2 emission reduction of 290 million and 960 million tonnes, respectively.

- The friction-related energy losses in an electric car are estimated to be only about half those of an internal combustion passenger car.

Potential actions to reduce friction in passenger cars include the use of advanced coatings and surface texturing technology on engine and transmission components, new low-viscosity and low-shear lubricants and additives, and tire designs that reduce rolling friction.

Ricardo Information Services – Fuel Economy & CO2 Reduction News – February 2012 IMPACT OF FUEL ECONOMY MEASURES ON OTHER SYSTEMS

DELIVERING COMPETITIVE NVH FROM LOW CO2 POWERTRAIN SOLUTIONS

Ricardo

The need for low CO2 vehicles is driving engine downsizing and the adoption of reduced cylinder count powertrains, with high torque levels available at low engine speeds. These trends, in addition to low friction design features, can have a significant negative impact on the NVH characteristics. This paper will discuss the Ricardo NVH development process and technologies to mitigate these concerns and achieve competitive NVH from low CO2 powertrains, thus enabling the use of such technologies. The process includes powertrain analysis, vehicle integration and calibration optimization.

Covers – low frequency engine vibration, combustion forces, sand quality, crankshaft torsional vibration, start-up and shutdown shake, turbocharging.

See vCD 37 Paper 13.pdf (1st International ATZ Conference on Automotive Acoustics, 7-8 Jul 2011, Zurich, Switzerland, 22pp.)

PLASTIC SOLUTIONS TO MEET SUSTAINABILITY TRENDS AND NEEDS IN THE AUTOMOTIVE AREA

DSM Engineering Plastics Asia Pacific

An overview is given of the various drivers, needs and trends in the automotive industry, and how these are matched by various new plastic solutions while significantly increasing the sustainability of various car systems and cars in total. These plastic solutions are demonstrated for eco-efficient solutions consisting of existing materials that contribute to sustainability of the car via component lifetime extension, or fuel/emission reduction due to weight savings or friction reduction. An alternative solution focuses on modification of the material itself by using non-hazardous substances as performance improvers, recycled based materials and bio-based plastics, like PA410. Application cases thereof are given to demonstrate potential in terms of sustainability indicators like CO2 reduction or fuel use.

Ricardo Information Services – Fuel Economy & CO2 Reduction News – February 2012 OPERATING STRATEGIES AND CONTROL

0D-1D COUPLING FOR AN INTEGRATED FUEL ECONOMY CONTROL STRATEGY FOR A HYBRID ELECTRIC BUS

University of Rome Tor Vergata, University of Tuscia and ENEA

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 powertrain. To this aim, an integrated approach realized by coupling a zero- dimensional model of the vehicle with a mono-dimensional model of the thermal engine to evaluate fuel consumption and find the most suitable control strategy for the engine (totally decoupled to the mission). A kinematic approach has been implemented. The power required to the motor is defined by knowing the speed and altitude profiles related to the path, while the power request for the engine is calculated by means of a first order filter, which properly cuts the power load of the motor. A sensitivity analysis has been performed in order to define the optimal operating strategy for the engine, to minimize the fuel consumption. Moreover, a control on the state of charge (SOC) has been implemented to assure a correct use of batteries and avoid damages.

BIOETHANOL HEATER FOR THE PASSENGER COMPARTMENTS OF ELECTRIC CARS

J Eberspacher

The paradigm shift in powertrain technology is resulting in new challenges for passenger compartment heating systems. As an alternative to electric heating systems, which reduce the driving range of electric vehicles, Eberspacher has developed a heater that runs on bioethanol, thus providing a CO2-friendly solution.

Covers – properties of different fuels.

Ricardo Information Services – Fuel Economy & CO2 Reduction News – February 2012 WASTE HEAT AND ENERGY RECOVERY

PERFORMANCE CHARACTERISTICS OF A RANKINE STEAM CYCLE AND BOILER FOR ENGINE WASTE HEAT RECOVERY

Korea Automotive Technology Institute, Korens Inc, Doowon Climate Control Co and Seoul National University

A dual-loop waste heat recovery system with Rankine steam cycles for improving the fuel efficiency of gasoline automobiles has been investigated. A high-temperature (HT) loop recovers waste heat only from the exhaust gas. A low-temperature (LT) loop recovers heat dissipation from the HT loop, and waste heat from the engine coolant. The two separate loops are coupled with a heat exchanger. This paper has dealt with the layout of the dual loop system, a review of working fluids, and the design of the cycle. The design points and the target heat recoveries of the HT boiler and LT boiler, which are core parts of their loops respectively, have been presented. The prototype of the HT boiler was evaluated by an experiment. For the performance evaluation of the HT boiler, the inlet temperature condition of the HT boiler working fluid was set to a degree of subcool of 5°C. The exit condition was the degree of superheat, which was set at 5°C. The characteristics of the HT boiler such as the heat recovery and pressure drops of fluids were evaluated for varying flow rates and inlet temperatures of the exhaust gas under various evaporating pressure conditions. Considering the characteristics of the cycle, the basic concept of the LT boiler has been determined to be a shell-and-tube type counter flow heat exchanger, the performance characteristics for various design parameters were analytically investigated.

PRESS HARDENING - THE LIGHTWEIGHT TECHNOLOGY FOR MAKING CARS WITH MORE SAFETY AND LESS CO2 EMISSION

Niobium Tech Asia

The worldwide automobile industry is currently focusing on developing autos of new generation with more safety, less CO2 emission and alternative energy. The key to success is the lightweight technology. As a perfect example of lightweight technology the author would like to present the press hardening technology from 3 major aspects: material, design and manufacturing. The press hardening technology breaks the bottleneck for application of ultra-high strength steels and makes it possible for carmakers to increase the strength level up to 1500 MPa for the safety relevant structure components and to achieve a weight reduction of about 20% without safety compromise and cost increase. Finally the recent developments with regard to press hardening technology will be explained.

See SAE 2011-28-0011 (2011, 6pp.)

LIGHTWEIGHTING OF PUBLIC TRANSPORT BUSES IN INDIA: AN IMPACT ANALYSIS

Technology Information Forecasting and Assessment Council (TIFAC)

Sustainable mobility has become priority in the wake of environmental concerns viz emissions and depletion of fossil fuels. The growing demand for more fuel-efficient vehicles to reduce energy

consumption and air pollution is a challenge for the automotive industry. Significant improvements in fuel economy can be obtained by weight reduction of vehicle as well as by improvements in engine and powertrain efficiency. If the vehicle body mass is reduced, there will be secondary mass reductions at the component level, particularly in the powertrain.

Globally, automotive manufacturers have been engaged in efforts to develop lighter alternatives using aluminium alloys and other light weight materials, so as to reduce the energy requirement, improve the fuel consumption and reduce vehicular emissions.

While the growth in mobility is growing rapidly in India, the installed base is still comparatively small, compared to the developed countries. Hence it would be possible to influence the growth of transportation systems, through policy measures, to lower the carbon footprint. This paper highlights potential of light weighting of public transport buses by use of aluminium for the super structure, body closure panels, and other structural components viz seat frames, windows, etc, and discusses a few innovative technologies that have to be employed for lightweight construction. A comparative study was carried out for lifecycle energy savings potential of aluminium intensive bus in comparison to conventional steel body bus, by taking into consideration Driving Cycle developed for Delhi city, India.

Ricardo Information Services – Fuel Economy & CO2 Reduction News – February 2012

LEGISLATION

GOVERNMENT PROPOSE FUEL CONSUMPTION LIMITS FOR CVs

China's Ministry of Industry and Information Technology has issued fuel consumption limits for heavy-duty commercial vehicles (the First Stage) to manufacturers for their comments.

Tables show - Rigid trucks - Proposed fuel consumption limits by gross vehicle weight (GVW) in litres/100km (excluding tippers); Tractors - Proposed fuel consumption limits by gross vehicle weight (GVW) in litres/100km; Coaches - Proposed fuel consumption limits by gross vehicle weight (GVW) in litres/100km.

DIESELS ARE GLOBAL STARS; US SHRUGS, STEPS ON THE GAS

Diesels offer clear benefits over gasoline. So at a time when automakers have to gear up for stringent fuel-economy rules - and clean-diesel technology has cleaned up diesel emissions - you might think that diesel's moment has come.

And, in fact, a few more diesels appear to be headed to the United States. But, for perspective, consider Honda Motor Co.

Honda's gasoline-engine Civic sedan is one of the best selling cars in the United States and also delivers respectable fuel economy, averaging 32 mpg for city and highway driving.

But last month in Tokyo, Honda gave reporters a sneak peek at a new fuel-efficient turbodiesel engine for the Civic. The new clean-burning 1.6-litre engine is physically smaller than Honda's other popular engines, lighter in weight and delivers the horsepower of bigger gasoline engines. Honda intends to start building the engine in late 2012 in hopes of improving the 2013 Civic's efficiency.

But not in the United States.

Under proposed US regulations for the 2017-25 model years, corporate average fuel economy would rise to 54.5 mpg in the 2025 model year, up from 30.1 mpg today. The industry needs to hit a 35.5 mpg CAFE by the 2016 model year.

Diesel engines deliver as much as a 40 percent boost in fuel economy. Graph shows comparison of diesel and gasoline fuel costs.

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