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Vienna Motor Symposium: Future trends in engine technology More than 1000 engineers and automotive professionals met during the 24th Motor Symposium in Vienna, 15-16 May, to exchange information on technology and market trends in future powertrains. The discussion focused on the European Union, but also included insights from the U.S. and Japanese markets. Presentations were given by engine and component manufacturers, as well as by top level management representatives from Ford, GM, Toyota, and Audi. In the long term, the directions in automotive powertrain technology remain vague and uncertain. Several companies hinted at hydrogen fuel cells as the "silver bullet" for the future. None of the presentations, however, focused on this technology and questions on fuel cells from the floor were left without answer. One can speculate that either the companies are unwilling to share experience on fuel cells, or else there is not enough progress to report. One notable exception was BMW, who shed some light on their future powerplant research. While focusing on hydrogen as the future automotive fuel, the BMW Group has been developing a H2-fueled internal combustion (IC) engine which, according to BMW, can provide better cost-efficiency in utilizing hydrogen than fuel cells (presentation by Burkhard Goeschel, BMW). The IC engine can also provide a smooth transition between today's and future fuels; BMW plans to put on the market a series production variant of the current 7 Series equipped with H2 combustion engine which will be able to run on both gasoline and hydrogen. The H2 engine would utilize direct injection and, in the long term, also turbocharging. It would be operated either at stoichiometric (lambda=1), where NOx emissions would be controlled by a three-way catalyst, or in the very lean region of lambda>2, where NOx emissions would be negligible. The BMW Group also announced a collaboration with General Motors to develop refueling devices for H2-fueled vehicles (in the case of GM, powered by fuel cells). Among other activities, the collaboration will cover setting global standards and specifications for the fuel and fuelling hardware. In the shorter term, the main development targets for automotive engines remain good fuel economy/low CO2 emission and low emissions of pollutants without compromising the performance. This is achieved by such "conventional" approaches as variable valve control, including continuing research into electronic valve control (K. Wunderlich, DaimlerChrysler), and increased electronic control of engine parameters in general. Fuel economy gains are also available in the transmission design. Double-clutch automatic transmission was reported to provide--for the first time--a better fuel economy than manual transmission (S. Goll, ZF Friedrichshaffen). A converging trend can be seen in gasoline and diesel engines. This can be illustrated by such features as the use of direct fuel injection in both types of engines. The gasoline and diesel compression ratio also becomes similar, with future diesels heading towards lower and gasoline towards higher compression ratios (T. Tomita, Toyota). These trends may be leading toward the development of new engine concepts. Due to the different emission emphasis in the EU (global warming and CO2) and in the USA (smog, HC/NOx), future passenger car engine technologies for these markets are likely to be different. A few years ago, lean-burn (stratified charge) gasoline direct injection (GDI) engines were seen as one of the major technologies to improve fuel economy of the gasoline engine. Although new GDI engines are being introduced (E. Voss, Opel; R. Menne, Ford), the fuel economy gain is less than once anticipated. In general, stratified GDI engines with open loop control strategy (no NOx sensor) achieve fuel economy benefit of about 6-8% (fuel economy test cycle). If closed loop control is used, the fuel economy improvement is about 10-12%. Furthermore, the fuel economy improvement strongly depends on the driving pattern; it may be only about 1-2% during high speed highway cruising. The stratified injection GDI engines must utilize NOx adsorber/catalysts for NOx control at lean exhaust conditions. This technology significantly increases the cost of the engine (about EUR 500 according to R. Menne of Ford). Dieselization of the passenger car market remains an important strategy to cut CO2 emissions in Europe. Gerhardt Schmidt (VP, Ford) also expressed support for the introduction of light-duty diesels in the U.S. market. His counterpart of GM, Thomas Stephens, was less optimistic for the future of light-duty diesels in the U.S. According to Stephens, there is no technology to meet the California LEV II standards on diesel passenger cars (but it may be feasible on LD trucks). Instead, hybrid strategies were emphasized in the GM presentation. Diesel fuel injection, perhaps the single most important technology responsible for the performance and emissions improvement in new diesel engines, also continues to evolve. The market is divided between common-rail and unit injector systems. "New generation" systems that are being developed feature increased number of injection events (3-5) with flexible rate shaping, increased injection pressures, and improved fuel atomization (smaller nozzle holes). For instance, the new piezo common-rail system from Siemens is capable of 1800 bar injection pressure (W. Schuerz, Semens). Presentations in the diesel emission aftertreatment sessions focused on diesel oxidation catalyst, diesel particulate filter, and NOx adsorber technologies. Emitec presented updates on new diesel catalyst concepts, including the pre-turbo catalyst and the "trap-catalyst", being developed to meet Euro 4 (2005) limits, as tested in cooperation with Volvo and Honda (R. Brueck, Emitec; Y. Unno, Emitec JP). A study analyzing various configurations of diesel particulate filter and NOx trap system was reported by T. Colliou and co-workers from IFP, France. A progress report on the diesel particulate and NOx reduction system (DPNR) by Toyota became a traditional component of the Vienna symposium (A. Shoji, Toyota). The DPNR includes a diesel particulate filter substrate coated with a NOx adsorber/catalyst, thus providing an elegant integration of both devices into one. The system was originally developed for a passenger car. It is regenerated through a sophisticated combination of engine combustion, in-cylinder post- injection, and exhaust fuel injection methods, in close integration with the engine management system. Commercial launch of DPNR-fitted cars has been anticipated for quite some time and, according to Toyota, is expected later this year. This year's presentation discussed an adaptation of the DPNR system for a light-duty truck, powered by a 4-liter diesel engine. The DPNR was subjected to 2000 hour durability test on an engine bench using fuel of 50 ppm sulfur. The initial NOx reduction efficiency of 85% dropped to 50% after the aging. This result was deemed sufficient for meeting the JP 2005 emission standards, but the authors suggested that operating the engine using a 10 ppm S fuel would result in improved NOx reduction. ------------------------ Yahoo! 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