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The front bumper of a current production vehicle, which is made of hot-stamped 15B21 aluminized steel, was studied for mass and cost reductions using the Advanced High Strength Stainless Steel product NITRONIC® 30 (UNS Designation S20400) manufactured by AK Steel Corporation. This grade of stainless steel offers a combination of high ductility and strength, which was utilized to significantly modify the design of the bumper beam to incorporate geometry changes that improved its stiffness and strength. The structural performance of the bumper assembly was evaluated using LS-Dyna-based CAE simulations of the IIHS 40% Offset Full-Vehicle Impact at 40 mph with a deformable barrier, and the IIHS Full Width Centerline 6 mph Low-Speed Impact. Optimization of the bumper beam shape and gauge was performed using a combination of manual design iterations and a multi-objective optimization methodology using LS-Opt.

Most applications for Dual Phase hot rolled steel have been large components like frame members that yield significant weight savings. Difficulties in secondary forming have limited the range of parts produced. One area with good potential is noise-vibration-harshness components (NVH), since such parts tend to be heavy gauge. Significant weight reduction should be possible through thinner steel without compromising design requirements, also potentially reducing cost as well. Fatigue properties of Dual Phase also match well with these applications. We have successfully produced a multi-stage deep drawn cup for an engine mount using DP590/600 from different steel sources, demonstrating this material can be used for a new group of applications.

The potential of advanced high strength steels such as TRIP versus conventional HSLA350 steel in achieving improved durability with weight savings is explored in the case of a shock tower assembly. Through a computational approach a linear analysis and a nonlinear analysis are performed. The nonlinear analysis takes into account the effect of geometry, material and contact nonlinearities. The results from both the linear and nonlinear analysis are used to predict fatigue lives. It is shown that the advanced steel grades, in particular, TRIP steels, can offer superior resistance to fatigue loading conditions while offering an opportunity to reduce the weight of the component.

The challenges of ever increasing combustion engine complexity coupled with the introduction of new and ever more stringent emissions regulations place a unique strain on the time available during the base engine hardware development and calibration phase of the product development cycle. Considering state of the art gasoline engine architecture (dual variable valve timing, direct injection with turbocharger) it is common to have at least 12 degrees of freedom as system inputs. The understanding of interactions and inter-dependencies of these inputs is therefore key in optimising the performance of the engine. MAHLE Powertrain has developed a process using a global Design of Experiment (DoE) technique based on Gaussian processes that can be used to accurately model and optimise many aspects of an engine’s performance.

The paper deals with an application of advanced simulation methods to modeling of hydrogen fueled engines. Two models have been applied - 0-D algorithm and CFD. The 0-D model has been based on GT-Power code. The CFD model has been based on Advanced Multizone Eulerian Model representing general method of finite volume. The influence of main engine parameters, e.g. air excess, spark timing, compression ratio, on NOx formation and engine efficiency has been investigated. Both models have been calibrated with experimental data. Examples of results and comparison with experiments are shown. The means of reducing NOx formation are discussed.

This paper summarizes the results of a broad survey study of the influence on weight of future large launch vehicles through use of advanced materials. Interrelationships of results with other factors such as design criteria, design approach, types of wall construction and advanced analysis techniques are considered. Specific results are presented for both advanced metals and wall construction techniques. New, computerized techniques used in developing these results are described, and applicability to similar future studies is noted.

Results are presented for a study conducted at the NASA Langley Research Center which examined the effects of advanced technologies on the performance and size of very large, long-range subsonic transports. The study was performed using the Flight Optimization System (FLOPS), a multidisciplinary system of computer programs for conceptual and preliminary design and evaluation of advanced aircraft concepts. A four-engine, baseline configuration representative of existing transport technology was defined having a payload of 412 passengers plus baggage and a design range of 7300 nmi. New 600, 800 and 1000 passenger advanced transport concepts were then developed and compared to the baseline configuration. The technologies examined include 1995 engines, high aspect ratio supercritical wings, composite materials for the wing, fuselage and empennage, and hybrid laminar flow control (HLFC).

The future emission limits for gasoline fuelled passenger cars require more and more efficient exhaust gas aftertreatment devices - the catalytic converter being one essential part of the complex system design. The present paper summarizes the results of several basic research programs putting major emphasis on the application of highly sophisticated three-way catalyst technologies being taylored for the utilization on ultra thin-wall ceramic substrates. In the first part of the investigation the following effects were examined in detail: Different washcoat loadings at constant PGM-loadings Different volumes of catalysts for constant amounts of PGM and washcoat Similar washcoat technologies at different ratios of WC-loading to precious metal concentration in the washcoat.

A review of the structural design and material selection in the YF-17 airplane is presented. Emphasis is placed on the choice of those design concepts and materials that are unique, and the effect on these choices of the prototyping philosophy is described. Special emphasis is placed on the use of graphite materials, but the use of other nonmetallic materials and the considerations involved in the selection of metallic alloys and heat treatments are also discussed.

Topology optimization is a branch of structural optimization which solves an optimal material distribution problem. The resulting structural topology, for a given set of boundary conditions and constraints, has an optimal performance (e.g. minimum compliance). Conventional 3D topology optimization algorithms achieve quality optimized results; however, it is an extremely computationally intensive task which is, in general, impractical and computationally unachievable for real-world structural optimal design processes. Therefore, the current development of rapid topology optimization technology is experiencing a major drawback. To address the issues, a new approach is presented to utilize the powerful abilities of large deep learning models to replicate this design process for 3D structures. Adversarial models, primarily Wasserstein Generative Adversarial Networks (WGAN), are constructed which consist of 2 deep convolutional neural networks (CNN) namely, a discriminator and a generator.

Aerospace human factors captures principles and findings of human behavior and performance as they apply in the aeronautics and the space environments. While there is a significant and growing body of aeronautical human factors data, space human factors remains limited. Fortunately, the similarities between spaceflight and airflight provide space planners with a valuable means of anticipating human-based issues, of leveraging from aeronautical human factors research and experience and of shortcutting what would otherwise be a long learning curve. This paper considers some of the areas where human factors research has made, or is making, significant impact on the conduct of airflight and where, with limited additional work, spaceflight could be brought to a similar level of understanding.

A number of data analysis techniques have been developed in the aerospace field to assist in the solution of shock and vibration problems. The potential value of several of these techniques to aid in the solution of crash safety problems is discussed. Each technique is illustrated by application to acceleration measurements from passenger vehicle crash tests.

With the ever increasing desire to improve the thermal efficiency of the internal combustion engine, the combination of gasoline direct injection with engine downsizing and intake charging may offer the greatest potential for maximizing the efficiency of these engines. Although the comparative benefit of direct injection alone may be reduced when compared to the downsized and charged engine directly, the combination of the two technologies has the potential to offer substantially larger total fuel consumption reduction in automotive applications than either technology independently. The Orbital developed air-assisted spray guided combustion system has unique properties which are shown to be desirable given the increased demand of boosted engine operation. The decoupling of fuel metering and direct injection events promotes large dynamic range of fuel metering and, when combined with variable fuel metering differential pressure, results in turn down ratios in excess of 24 to 1.

The idea of long-life turbomachinery that requires no oil or servicing is immediately attractive. The concept of air-lubricated bearings provides the basis for such a design. This paper describes the advantages and problems in the application of air bearings to closed-and open-cycle machinery. It discusses the design and performance characteristics of several prototype air bearing machines. The results of extensive ground tests and thousands of hours of field experience prove that practical air bearing turbomachines for open-cycle applications are a reality.

This research paper builds onto the wealth of technical information that has been published in the past by engineers such as Flick, Radlinski, and Heusser. For this paper, the pushrod force versus chamber pressure data published by Heusser are supplemented with data taken from brake chamber types not reported on by Heusser in 1991. The utility of Heusser's braking force relationships is explored and discussed. Finally, a straightforward and robust method for calculating truck braking performance, based on the brake stroke measurements and published heavy truck braking test results, is introduced and compared to full-scale vehicle test data.

At the upstream part of the Three-Way Catalyst (TWC) an O₂ sensor (UpO₂S) is used for O₂ Feedback Control (O₂F/B) that controls the air-fuel ratio (A/F) close to the stoichiometric level. O₂ sensor has a bit of individual characteristic difference as for the switching the excess air ratios of output (λ shift). This phenomenon becomes remarkable according to the effects of unburnt elements in exhaust gas. Despite the O₂F/B implementation, A/F isn't controlled to the stoichiometric level and the conversion efficiency of the TWC could be lower. Maintaining a higher level of TWC conversion efficiency requires more accurate A/F control and corrections of the UpO₂S λ shift issue. Therefore, using an O₂ sensor at the downstream part of the TWC (DownO₂S)~where the effects of unburnt elements in exhaust gas are smaller~can be an effective way to restore these challenges.

This paper describes an air pollution control strategy that utilizes air pollutant damage functions. Air pollutant damage functions relate economic losses to man and his environment to varying levels of air pollution. The use of damage functions allows the strategist to develop an air pollution control program which considers benefits and costs of control as decision criteria. In this work, damage functions were calculated for six major pollutants. Using damage functions, benefits (reductions in damages) resulting from control of automobile exhaust in 1966-1977 are compared with the costs of control. The utility of a damage function in selecting candidates for an air pollution control program and in determining optimum level of control is illustrated. The application of damage functions to control of auto exhaust is illustrative, not definitive.

1 There is an increasing demand to improve the fuel economy of motorcycles in recent years. The lean-burn combustion is one effective means of accomplishing this. However, it is difficult to introduce the lean-burn concept while maintaining the high output and the quick response these are important for application to motorcycles. In this research, we have developed a fuel supply system that realizes both the quick response and the stable lean combustion using a conventional injector targeted for small motorcycles. This system intensifies the in-cylinder flow and helps the fuel droplet atomization, much better than conventional system due to air flow generated by the additional the passage. Therefore these improve the air-fuel mixture formation and flame propagation. As a result, it was possible to make the air-fuel mixture leaner while improving the throttle response by shortening the distance over which the fuel is carried.

The combustion and air system development of the air-to-air charge cooled two-stroke cycle diesel engine for the heavy-duty truck market is described. The conceptual modifications to the actual turbocharged-charge cooled diesel cycle are defined and supported by analytical modeling results and engine dynamometer development test results. Actual engine and vehicle performance are provided to demonstrate the significant achievement in fuel efficiency made via the optimizing scheme employed.

AN investigation of airborne radar of 5.5-cm wavelength to be used for weather mapping is discussed in this paper. Results show that radar of this wavelength paints an accurate picture of the weather, thus permitting the pilot to detour a storm area with a minimum increase in flight time or to navigate through a storm while avoiding areas of heaviest turbulence. In addition, this radar provides warning of hail shafts or tornadoes or of impending collision with terrain; its good terrain-mapping ability enables the pilot to scan an airport area to determine best possible flight paths.