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Measurement and Evaluation of Aerodynamic Noise

Nissan Motor Co.,Ltd-Nozomi Iida
Published 1999-03-04 by SAE International in United States
Recently, aerodynamic noise which originates in the flow of the body surroundings is actualized as a main cause of an automobile interior noise when running at high speed, because engine, power train and tire noise have been greatly decreased. Along with it, the measurement technology for the phenomenon elucidation and the evaluation has been demanded to decrease aerodynamic noise.In this paper, typical measurement examples of aerodynamic noise are introduced. These measurement technologies can be classified, and arranged to four types of measurements, which are flow, external noise, transmission psth and interior noise. This paper presents how the advancement of these measurement technologies has contributed to the aerodynamic noise elucidation. Moreover, the latest evaluation method of aerodynamic noise and the trend in the future to the demand of customer's many topics are introduced.
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On-board Hydrogen Generation for PEM Fuel Cells in Automotive Applications

Johnson Matthey-Ian Carpenter, Neil Edwards, Sue Ellis, Jack Frost, Stan Golunski, Nick van Keulen, Mike Petch, John Pignon, Jessica Reinkingh
Published 1999-03-04 by SAE International in United States
In the search for clean and efficient power, PEM fuel cells have been identified as the technology that can meet our future needs for transport applications. Hydrogen-powered PEM fuel cell vehicles are perceived to give the ultimate advantage, but the complications involved with hydrogen storage and refuelling, as well as the lack of infrastructure call for a different solution. In the near term, this is almost certain to be the on-board generation of hydrogen from a readily available fuel.At Johnson Matthey, a novel modular reformer (HotSpot™) has been developed for methanol, and has been demonstrated to have many of the qualities that are required for automotive applications. Auxiliary technologies for CO removal (Demonox) and aftertreatment have also been developed, and integrated with the reformer to form 20 kWe processor, which is currently undergoing brass-board testing. Although not designed for multi-fuel operation, HotSpot is versatile, and can be adapted for other fuels apart from methanol. A 5 kWe natural-gas processor has recently been demons-trated, in tests that have included successful coupling with a PEM fuel cell.
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Timken: From Missouri to Mars – The History of the Future

The Timken Company-Thomas W. Strouble
Published 1999-03-02 by SAE International in United States
The 100-year saga of The Timken Company is a testament to the enduring power of innovation, grit and periodic self-renewal. It is the story of a quest to solve one of industry's oldest, most limiting and expensive challenges: friction. Today's Timken combines materials science with bearing technology to produce products that range from a half ounce to nine tons and help power and control applications that span disk drives, drilling rigs, dental drills and rolling mills. Today's automotive bearing is less than half the size and 90 percent lighter than its ancestor - and carries twice the load.
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Light Turbocharger Compressor Wheels from Aluminium and Magnesium Investment Casting

Fraunhofer-Institut for Operational Strength of Structures (LBF)-Cetin Morris Sonsino, Heinz Kaufmann
Kühnle, Kopp, Kausch AG (KKK)-Rudolf Keiper
Published 1999-03-01 by SAE International in United States
Within the scope of a team work between Kühnle, Kopp & Kausch AG (KKK), Volkswagen AG, Sterling International Technologies Ltd. and the Fraunhofer Institute for Strength of Structures under Operational Conditions (LBF) compressor wheels of aluminium and magnesium investment casting were developed and investigated. Strength and fatigue tests, overspeed and field tests as well as metallographic checks were made in addition to the finite element calculations to optimize the stress under centrifugal forces in an appropriate way for the materials involved. The results and the knowledge gathered are to clarify whether magnesium alloys are an appropriate replacement for the proven standard aluminium alloy for turbochargers.
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ULSAS - Improving Performance Through Light Weight Automotive Suspension Systems: Phase 1 - Benchmarking and Initial Design Concepts

Lotus Engineering-Nicholas J. Sampson, David A. Thomas
ULSAS Programme Director-Peter Rawlinson
Published 1999-03-01 by SAE International in United States
A Consortium of steel producing organizations has been working to reduce the mass of automobiles. An initiative identified as ULSAS (UltraLight Steel Automotive Suspension) is in progress which considers automotive rear suspension systems. The programme has evaluated and established the current status of material and process technology utilization and its application to rear suspension systems. Extensive studies have generated over fifty five design ideas which provide an indication of the potential opportunities for performance improvement that could be realised through the focused application of steel technologies. Work is in progress developing these ideas and quantifying the performance improvements.
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An Assumed Modes Method Approach to Disc Brake Squeal Analysis

A/S Roulands Fabriker, Odense, Denmark-John Flint
Chalmers University of Technology, Göteborg, Sweden-Johan Hultén
Published 1999-03-01 by SAE International in United States
Disc brake squeal is a widespread cause for discomfort. The purpose of the work is to gain insight into the disc brake squeal problem and to investigate the mechanisms that generate instabilities that leads to audible noise. This paper presents a mathematical model for high frequency disc brake noise. Information of the flexible properties of the components is used to generate a small yet appropriate model. By using the technique of “Assumed Modes Method”, a model incorporating the flexible properties of a continuous disc can be accomplished resulting in only a limited number of degrees of freedom. Knowledge of the modal properties of disc and pads are used to select assumed modes for the model components. The basic concept of mode coupling is the starting point: Two orthogonal modes are present in a disc at the same frequency owing to it's rotational symmetry. When the pad-disc contact is established, this external disturbance causes the pairs of modes to split-up and they will coexist at different frequencies. Non-conservative effects, such as the friction forces, will tend…
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European Side-markers Effect on Traffic Safety

TNO-Human Factors Research Institute/ Netherlands-Jan Theeuwes, Johan W.A.M. Alferdinck
Volvo Car Corporation-Albert Roelfsema
Published 1999-03-01 by SAE International in United States
In 1993 new European legislation regarding side-markers for passenger cars became effective.Volvo requested the TNO-Human Factors Research Institute (HFRI) to investigate the possible safety benefit of this European side-markers configuration. A test panel at TNO- HFRI was used to determine the difference in response time and detection error of drivers, confronted with slides of vehicles with and without the mentioned new vehicle side-marker configuration in several visibility conditions, crossing illumination and different vehicle approach angles. The investigation showed a significant faster vehicle recognition with less detection errors in case the approaching car was equipped with the bright amber side-markers. This improved vehicle conspicuity can be a benefit in crash avoidance, especially when the driver approaches a crossing with complex light environment and reduced visibility.Allowing the bright amber European side-markers in US legislation could be the start of better crash avoidance worldwide.
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Thermodynamic and Cycle Models for a Low-Pressure CO2 Refrigeration Cycle

Ford Motor Co.-Michael L. Greenfield, George Mozurkewich, William F. Schneider
Visteon Automotive Systems-Gary D. Bramos, David C. Zietlow
Published 1999-03-01 by SAE International in United States
Carbon dioxide (CO2)-based refrigeration systems have been proposed as environmentally benign alternatives to current automotive air conditioners. The CO2 vapor-compression system requires very high operating pressures and complicated control strategies. Recent experimental results indicate that operating pressures comparable to those of current automotive air conditioners can be attained by the inclusion of a secondary carrier fluid (a “co-fluid”), with solution and desolution of the CO2 from the co-fluid substituting for condensation and vaporization of pure CO2.In this work, modeling tools have been developed to optimize the CO2/co-fluid cycle, including the selection of a co-fluid, the CO2/co-fluid ratio (the “loading”), and the operating conditions. The modeling tools are based on thermodynamic functions (e.g. enthalpy and entropy), which are shown to depend on the heat capacities, densities, and isothermal compressibilities of pure CO2 and of the co-fluid, as well as on the heat of solution of the two. The methodology is demonstrated for a CO2/N-methyl-2 pyrrolidone (NMP) mixture.An ideal refrigeration cycle model was constructed for the CO2/co-fluid system, using the thermodynamic functions as inputs. The optimal cycles…
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Numerical Modelling of Tailored Blank Applications for Autobody Components

Thyssen Krupp Stahl AG-Klaus W. Blümel, Peter Ufermann
Thyssen Steel Group-John Graham
Published 1999-03-01 by SAE International in United States
Tailored Blank applications have become more and more important for the advanced light weight and cost effective steel automobile body. During the last decade, the production of Tailored Blanks with a straight weldline has been constantly increasing because their technical and economical advantages are well accepted by automobile manufacturers /1, 2, 3, 4/. But, now the body engineers prefer to have an even more flexible product with specific weldline design, according to the engineering design needs. Thyssen Krupp Stahl AG reacted quickly on this demand and now offers the new product called, Thyssen Engineered Blanks (TEB®s), which meets almost all the needs for the design of components concerning weld-line geometry and weld-line positioning. With our new production line, both single and multiple steel sheets can now be joined together with linear weld-lines, angled weld-lines and curved laser beam weld-lines, Figure 1. To optimize the application of this new technology, the TEB® parts development process needs to be intensively supported by numerical modeling for feasibility reasons. Given the difficulty to analyze the stamping of sheet steel…
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Isolating Hydraulic Noise from Mechanical Noise in Power Rack & Pinion Steering Systems

Delphi Automotive Systems-Michael R. Long
Published 1999-03-01 by SAE International in United States
The purpose of this report is to quantify the methodology for evaluating and isolating rattle noises in power rack & pinion steering systems. In today's ever changing market of vehicle body & suspension changes, it's very important that the correct process be used to identify the correct noise source. The results of this evaluation procedure will help sort out the difference between hydraulic generated noises and mechanical generated noises.The process used in sorting the hydraulic noise from the mechanical noise is through the use of a “standpipe”, which dampens the hydraulic reaction pulse in the hydraulic steering system. We refer to this hydraulic pulse as “hydraulic rattle”, and is often confused with mechanical rattle during vehicle evaluations. The concept of the standpipe is similar to that used in household plumbing, which reduces the effects of hydraulic hammering in the water pipes.
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