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Experimental and numerical approaches were adopted to understand flow behavior and performance of centrifugal fans in an automotive HVAC blower system. This work is directed at improving the performance of a conventional forward-curved centrifugal fan for a given small scroll casing. Recent requirements in the design of the multiblade centrifugal fan being used in automotive HVAC blowers are not only higher pressure rise and lower noise, but also better packaging in the automobile cabin. In order to meet these requirements, among various well-known design factors affecting the fan performance, principal parameters related to the rotor shape were modified and detailed flow analysis was carried out. Measurements have been made by means of a miniature five-hole probe and a pressure scanning system connected to an online data acquisition system.

The design of the newly developed Toyota AZ series 4 cylinder engine has been optimized through both simulations and experiments to improve heat transfer, cooling water flow, vibration noise and other characteristics. The AZ engine was developed to achieve good power performance and significantly reduced vibration noise. The new engine meets the LEV regulations due to the improved combustion and optimized exhaust gas flow. A major reduction in friction has resulted in a significant improvement in fuel economy compared with conventional models. It also pioneered a newly developed resin gear drive balance shaft.

Aqua-ammonia absorption refrigeration cycle and R-134a Vapor jet-ejector refrigeration cycle for automotive air-conditioning were studied and analyzed. Thermally activated refrigeration cycles would utilize combustion engine exhaust gas or engine coolant to supply heat to the generator. For the absorption system, the thermodynamic cycle was analyzed and pressures, temperatures, concentrations, enthalpies, and mass flow rates at every point were computed based on input parameters simulate practical operating conditions of vehicles. Then, heat addition to the generator, heat removal rates from absorber, condenser, and rectifying unit, and total rejection heat transfer area were all calculated. For the jet-ejector system, the optimum ejector vapor mass ratio based on similar input parameters was found by solving diffuser's conservation equations of continuity, momentum, energy, and flow through primary ejector nozzle simultaneously.

Fulfillment of SULEV standards without catalyst - this is a target engineers at IAV have been working on since the middle of the 1990s. The core of this development is an advanced steam engine with a high performance burner. This burner features extremely low raw pollutant emission. This paper describes new solutions that were found to solve the challenging tasks in the development of such an engine concept.

A thermal management system for heavy duty diesel engines is presented for maintaining acceptable and constant engine temperatures over a wide range of operational conditions. It consists of a computer controlled variable speed coolant pump, a position controlled thermostat, and a model-based control strategy. An experimentally validated, diesel engine cooling system simulation was used to demonstrate the thermal management system's capability to reduce power consumption. The controller was evaluated using a variety of operating scenarios across a wide range of loads, vehicle speeds, and ambient temperatures. Three metrics were used to assess the effects of the computer controlled system: engine temperature, energy savings, and cab temperature. The proposed control system provided very good control over the engine coolant temperatures while maintaining engine metal temperatures within a desired range.

Powder metallurgy (P/M) industry has been known for the capability of producing near-net-shape parts. Its specific characteristics have resulted in lower production costs and eliminating many secondary machining. However, more and more P/M parts do require additional operations to fulfil their complex geometry features and surface roughness. Many of the machining factors that influence the machinability of cast and wrought steel parts, such as cutting speed, feedrate, coolant, tool geometry and shape, are also considered in the machining of P/M parts. However, composition, structure, and porosity of P/M are additional factors to be considered. Porosity in the P/M structure can decrease the machinability and shorten the tool life. Different variables have been considered in the material composition. Material densities and the free-machining additive manganese sulphide (MnS) are the two main factors of material composition, which dominate the machining performance.

Due to the wide and ever increasing application of thermoplastics for the transportation and automotive industries, the performance of the under-the-hood plastic parts depend upon optimized design and processing technology and properties of polymer based materials. Nylon (polyamide) based plastics are used widely for automotive cooling fans and various under-the-hood injection molded components. For injection molding of multi-blade cooling fans and various rotating plastic parts the complex of multiple gating injection molding tools were used. Both the design of the various rotating parts (including industrial and automotive cooling fan, and the molding tool design are very important to get optimum flow patterns and to predict the locations and interaction of stress-bearing areas and knit lines (planes or inter-phases)1. The mechanical performance of the injection-molded thermoplastic components depends on the peculiarity of the part and the molding tool design.

Engineering thermoplastics were successfully utilized in the design of injection molded rotating parts such as the impellers, wheels, and cooling fans of commercial air-cooled chillers, and gas and diesel engines. Complex aerodynamic and mechanical performance of impellers and cooling fans are very important for the efficiency of integrated air-movement, climate control and cooling systems of various types of engines of vehicles, cars, heavy-duty tractors and trucks. The transportation and automotive industries have developed a culture of reliability and cost effectiveness, in which high risks and adventures are not encouraged. Due to the wide and ever increasing application of thermoplastics for the transportation and automotive industries, the performance of the under-the-hood parts depend upon optimized design and processing technology and properties of polymer based materials.

A mathematical model for a hydraulic power steering system was constructed and numerical analysis was performed for self-excited vibration caused by rapid steering in the power steering system. From the examination, the guide of the prevention against the vibration was derived, such as positioning the rather long hose at near the power steering gear in the supply line, and the mechanism of the prevention was clarified. Moreover, the mathematical model and the guide of the prevention were verified by bench tests.

The LEV II and EURO V legislation in 2007/2008 require a high conversion level for nitrogen oxides to meet the emission levels for diesel SUVs and trucks. Therefore, U.S. and European truck manufacturers are considering the introduction of urea SCR systems no later than model year 2005. The current SCR catalysts are based mainly on systems derived from stationary power plant applications. Therefore, improved washcoat based monolith catalysts were developed using standard types of formulations. These catalysts achieved high conversion levels similar to extruded systems in passenger car and truck test cycles. However, to meet further tightening of standards, a new class of catalysts was developed. These advanced type of catalytic coatings proved to be equivalent or even better than standard washcoat formulations. Results will be shown from ESC, MVEG and US-FTP 75 tests to illustrate the progress in catalyst design for urea SCR.

This paper presents the experimental work and the results obtained from the implementation of a transient fuel compensation algorithm for the 6.0-liter V12 high-performance engine that equips the Lamborghini Diablo vehicles. This activity has been carried out as part of an effort aimed at the optimization of the entire fuel injection control system. In the first part of the paper the tests for fuel film compensator identification are presented and discussed. In this phase the experimental work has been conducted in the test cell. An automatic calibration algorithm was developed to identify the well-known fuel film model X and τ parameters, so as to define their maps as a function of engine speed and intake manifold pressure. The influence of engine coolant temperature has been investigated separately; it will be soon presented together with the air dynamics compensation algorithm. In the second part of the paper, the performance of the fuel dynamics compensation algorithm is analyzed.

For years, secondary air injection Systems have been used to reduce hydrocarbon exhaust emissions for a short period after engine cold start. In the beginning, passive secondary air systems were used, with the airflow driven by the pressure pulsations in the exhaust system. Since 1990, for most applications, active secondary air systems (i. e., systems where air is injected into the hot exhaust gases by a pump) have been employed. Secondary air injection into the hot exhaust gases is realized by a d-c motor driven turbine pump, i. e. a secondary air pump, and a control valve. Numerous factors, including raw engine emissions during cold start and warm up, driveability requirements and the need to adapt to different emissions legislation, dictate the use of secondary air injection systems. The development of other exhaust aftertreatment systems, e. g., close-coupled or heated catalysts as well as packaging and cost factors will influence the market penetration of secondary air systems.

A breakthrough catalyst technology utilizing new mixed metal oxides in conjunction with Platinum Group Metals has been developed. Stable synergies are designed into the catalyst washcoat that enable high performance and durability to be achieved at low Platinum Group Metal usage. Extensive vehicle data is reported on catalysts aged using a variety of high-temperature accelerated aging cycles. Vehicle performance at the LEV, ULEV and LEV-II levels is discussed in the context of unique calibration-catalyst interactions. Conclusions concerning further areas of improvement and future applications are also reviewed.

Some engineers in the U.S. are still hesitant to change from graphite cylinder head gaskets to MLS designs due to surface finish capabilities at engine plants and in the aftermarket. Sealing these various hardware surface finishes is accomplished via a rubber on the surface. The coating's ability to conform to various surface irregularities while withstanding high temperatures, long term coolant and oil exposure, and joint shearing forces is paramount to long term sealing. This paper will explore the sealing capabilities of a highly conformable flouro-polymer rubber coating developed specifically to seal rougher surface finishes.

As a part of the FutureTruck 2000 advanced technology student vehicle competition sponsored by the US Department of Energy and General Motors, West Virginia University has converted a full-size sport utility vehicle into a high fuel efficiency, low emissions vehicle. The environmental impact of the Chevrolet Suburban SUV, in terms of both greenhouse gas emissions and exhaust emissions, was reduced through hybridization without losing any of the functionality and utility of the base vehicle. The approach taken was one of using a high efficiency, state-of-the-art direct injection, turbocharged diesel engine coupled to a high output electric traction motor for power assist and to recover regenerative braking energy. The vehicle employs a state-of-the-art combination lean NOx catalyst, oxidation catalyst and particulate filter to ensure low exhaust emissions.

The University of Maryland team converted a model year 2000 Chevrolet Suburban to an ethanol-fueled hybrid-electric vehicle (HEV) and tied for first place overall in the 2000 FutureTruck competition. Competition goals include a two-thirds reduction of greenhouse gas (GHG) emissions, a reduction of exhaust emissions to meet California ultra-low emissions vehicle (ULEV) Tier II standards, and an increase in fuel economy. These goals must be met without compromising the performance, amenities, safety, or ease of manufacture of the stock Suburban. The University of Maryland FutureTruck, Proteus, addresses the competition goals with a powertrain consisting of a General Motors 3.8-L V6 engine, a 75-kW (100 hp) SatCon electric motor, and a 336-V battery pack. Additionally, Proteus incorporates several emissions-reducing and energy-saving modifications; an advanced control strategy that is implemented through use of an on-board computer and an innovative hybrid-electric drive train.

Numerical 3-D simulations are performed for the improvement of the new direct injection gasoline engine. A solution based local grid refinement method has been developed in order to reduce the CPU time. This method has been incorporated into the CFD program (STAR-CD) with in-house spray and combustion models. Calculation results were compared with the experimental data taken by the LIF technique, and good agreement was obtained for the mixture formation and combustion processes. Some calculations were carried out for the fuel-air mixture formation process during late injection stratified combustion and the following results were obtained. The unburnt fuel has a tendency to remain in the side of the piston cavity at the latter part of the combustion period. To reduce the amount of unburnt fuel, it was shown that the combination of a thin thickness fan spray and compact cavity forms a spherical mixture, suitable for combustion.

This paper describes the motivation for developing hydrogen-fueled engines for use in hybrid electric vehicles of the future. The ultimate motivation for using hydrogen as an energy carrier is carbon management. However, air quality concerns also provide motivation for developing hydrogen-fueled vehicles. For this reason, we discuss the position of the hydrogen-powered hybrid vehicle within the California Air Resources Board requirement for Zero Emission Vehicles. We describe the expected performance of an electrical generation system powered by a four-stroke, spark-ignited, internal combustion engine for a hydrogen-powered hybrid vehicle. The data show that the engine-out emissions of NOx will allow the vehicle to operate below the Super Ultra-Low Emission Vehicle standard set by the California Air Resources Board. The engine can run on either hydrogen or blends of hydrogen and natural gas. The engine can be optimized for maximum efficiency with low emissions.

In order to match catalyst OBDII conditions the common procedure is oven aging with air, which is not suitable for complete converter systems due to mantle corrosion. The goal was, therefore, to find an alternative procedure to ensure a defined catalyst aging that would match 1,75 times the emission standard and is also good for SULEV. The new procedure currently being developed allows the aging of metal and ceramic catalysts as well as complete catalyst systems. The paper will present the aging process, emission data of fresh and aged catalysts and the feedback to the test car OBDII system.

Dual-monolith converters containing Pd-only catalysts followed by Pt/Rh three-way catalysts (TWCs) provide effective emission solutions for NLEV and Tier IIa close-coupled dual-bank V-8 applications due to optimal hydrocarbon and NOx light-off, transient NOx control, and balance of precious metal (PGM) usage. Dual-catalyst [Pd +Pt/Rh] systems on a 5.3L V-8 LEV light truck vehicle were characterized as a function of PGM loading, catalyst technology, and substrate cell density. NLEV hydrocarbon emission control of the 6500 lb vehicle was optimal using dual 1.2L converters with each containing front ceria-free Pd catalysts coupled with rear Pt/Rh TWCs. Advanced non-air prototype calibrations coupled with reduced catalyst washcoat mass on 600cpsi/4mil substrate resulted in minimal Pd usage of ∼0.02 toz/vehicle due to achieving catalyst inlet temperatures of 350-400°C in <10 sec on both banks of the V-8 engine.