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A mobile and dispersed power system is necessary for an advanced technological-industrial society. Today's petroleum-based system discharges waste products and heat and is growing exponentially. Energy resource commitment has already intersected “ultimate” low-cost petroleum supplies in the United States and will do so for the world before 2000; this portends major changes and cost increases. The twenty-first century system for mobile-dispersed power will reflect the energy source selected to replace petroleum-for example, coal, solar insolation, or uranium. It will incorporate a fuel intermediate such as methanol, ammonia, or hydrogen, and a suitably matched “engine.” The complete change will require more than 25 years because of the magnitude, fragmentation, structural gaps, complexity, and variety of the mobile-dispersed power system.

Although in-cylinder optical diagnostics have provided significant understanding of conventional diesel combustion, most alternative combustion strategies have not yet been explored to the same extent. In an effort to build the knowledge base for alternative low-temperature combustion strategies, this paper presents a comparison of three alternative low-temperature combustion strategies to two high-temperature conventional diesel combustion conditions. The baseline conditions, representative of conventional high-temperature diesel combustion, have either a short or a long ignition delay. The other three conditions are representative of some alternative combustion strategies, employing significant charge-gas dilution along with either early or late fuel injection, or a combination of both (double-injection).

Methanol fuel was tested in a prototype 2-cycle ceramic heat insulated engine with a swirl chamber. It was found that the 2-cycle ceramic heat insulated engine with a compression ratio of 18:1 could ignite methanol without an auxiliary ignition system and emissions were substantially reduced in the whole load range.

Cross-sectional distributions of the liquid phase temperatures in fuel sprays were measured using a laser-induced fluorescence technique. The liquid fuel (n-hexadecane or squalane) was doped with pyrene(C16H10). The fluorescence intensity ratios of the pyrene monomer and excimer emissions has temperature dependence, and were used to determine the liquid phase temperatures in the fuel sprays. The measurements were performed on two kinds of sprays. One was performed on pre-heated fuel sprays injected into surrounding gas at atmospheric conditions. The other was performed on fuel sprays exposed to hot gas flow. The spray was excited by laser radiation at 266nm, and the resulting fluorescence was imaged by an intensified CCD camera. The cross-sectional distribution of the liquid phase temperature was estimated from the fluorescence image by the temperature dependence of the intensity ratio.

The Ultimate GD&T Pocket Guide explains the most common rules, symbols, and concepts used in geometric dimensioning and tolerancing. ...This one-of-a-kind reference guide includes over 100 detailed drawings to illustrate concepts, more than 40 charts for quick reference, explanations of each GD&T symbol and modifier and much more...Written by standards expert Alex Krulikowski, this valuable on-the-job reference clarifies how to interpret standard-compliant technical drawings that use ASME Y14.5-2009.

On January 14, 2004 President George W Bush outlined a new vision for NASA that has humans venturing back to the moon by 2020. With this ambitious goal, new tools and models have been developed to help define and predict the amount of space radiation astronauts will be exposed to during transit and habitation on the moon. A representative scenario is used that includes a trajectory from LEO to a Lunar Base, and simplified CAD models for the transit and habitat structures. For this study galactic cosmic rays, solar proton events, and trapped electron and proton environments are simulated using new dynamic environment models to generate energetic electron, and light and heavy ion fluences. Detailed calculations are presented to assess the human exposure for transit segments and surface stays.

A lightning mapping system has been developed that locates the sources of VHF radiation from lightning discharges in three spatial dimensions and time. The system consists of several VHF receivers distributed over an area of about 100 km diameter. The system locates VHF radiation sources over the array with an accuracy of about 100 m. The system locates sources out to 250 km from the center of the array with reduced accuracy. The observations are found to reflect the basic charge structure of electrified storms.

The vehicle Heating, Ventilation and Air conditioning (HVAC) system is designed to meet both the safety and thermal comfort requirements of the passengers inside the cabin. The thermal comfort requirement, however, is highly subjective and is usually met objectively by carrying out time dependent mapping of parameters like the velocity and temperature at various in-cabin locations. These target parameters are simulated for the vehicle interior for a case of hot soaking and its subsequent cool-down to test the efficacy of the AC system. Typically, AC performance is judged by air temperature at passenger locations, thermal comfort estimation along with time to reach comfortable condition for human. Simulating long transient vehicle cabin for thermal comfort evaluation is computationally expensive and involves complex cabin material modelling.

This SAE Aerospace Information Report (AIR) describes field-level procedures to determine if 400 Hz electrical connections for external power may have been subjected to excessive wear, which may result in inadequate disengagement forces.

This paper presents a discussion of the component evaluation and design development work performed in developing a 4300 F reentry vehicle nose cap temperature sensor. Material compatabilities, insulation resistance, and atmospheric pressure effects on bare wire calibration data are discussed in some detail. The final design is outlined and the application problems discussed. The probe utilizes: a sintered iridium high temperature sheath (4300 F) and platinum 20% rhodium as the low temperature sheath (3000 F); beryllia as insulation -- hard fired at 4300 F and compacted powder at 3000 F; tungsten versus tungsten 26% rhenium as the thermocouple pair.

The new small and lightweight 2-cylinder liquid-cooled OHC gasoline engines were developed. These new engines are featuring high output, low vibration and noise radiation and so able to improve the comfortableness and amenity of applied utility machines. In this paper, the features of the new engines and the process to realize development targets are introduced. The basic structure adopted on the new engines is a liquid-cooled, inline 2-cyilinder layout with 360-degree firing intervals, twin balancer shafts, and an overhead camshaft that is driven by a cogged belt. Also various parts made of aluminum alloy and plastics could make the engine lighter. By these measures, the new engines could satisfy their hardest development targets, and realize their easy installation, higher versatility, and have the excellent features such as compact size, lightweight, high output, low exhaust gas emission and low vibration and noise radiation.

Triggered explosions are increasingly becoming common in the world today leading to the loss of precious lives under the most unexpected circumstances. In most scenarios, ordinary citizens are the targets of such attacks, making it essential to design countermeasures in open areas as well as in mobility systems to minimize the destructive effects of such explosive-induced blasts. It would be rather difficult and to an extent risky to carry out physical experiments mimicking blasts in real world scenarios. In terms of mechanics, the problem is essentially one of fluid-structure interaction in which pressure waves in the surrounding air are generated by detonating an explosive charge which then have the potential to cause severe damage to any obstacle on the path of these high-energy waves.

A 3D-CFD model with detailed chemical kinetics was developed to investigate the combustion characteristics of HCCI engines, especially those fueled with hydrogen and n-heptane. The effects of changes in some of the key important variables that included compression ratio and chamber surface temperature on the combustion processes were investigated. Particular attention was given, while using a finer 3-D mesh, to the development of combustion within the chamber crevices between the piston top-land and cylinder wall. It is shown that changes in the combustion chamber wall surface temperature values influence greatly the autoignition timing and location of its first occurrence within the chamber. With high chamber wall temperatures, autoignition takes place first at regions near the cylinder wall while with low surface temperatures; autoignition takes place closer to the central region of the mixture charge.

This paper presents a computational technique using Boundary Element method for the prediction of sound radiated by axisymmetric bodies with arbitrary boundary conditions. By taking the advantage of the axisymmetric property of the body the three dimensional integral formulation is reduced to one dimensional integral along the generator of the body. The arbitrary boundary conditions is expanded in Fourier series with a period of 2π. The integral equation is solved using superposition principle involving each term of the series. By adding the result associated with each term the final solution is obtained. A numerical procedure is implemented using curvilinear isoparametric element representatation. Examples are given involving an oscillating sphere and a half vibrating sphere. The results are compared with the analytical solution in which good agreement has been obtained.

As humans move into outer space, need for air, clean water and food require that green plants be grown within all planetary colonies. The complexities of ecosystems require a sophisticated understanding of the interactions between the atmosphere, all nutrients, and life forms. While many experiments must be done to find the relationships between mass flows and chemical/energy transformations, it seems necessary to develop generalized models to understand the limitations of plant growth. Therefore, it is critical to have a robust modelling capability to provide insight into potential problems as well as to direct efficient experimentation. Last year we reported on a simple leaf model which focused upon the mass transfer of gases, radiation/heat balances, and the production of photosynthetically produced carbohydrate. That model indicated some of the plant processes which had to be understood in order to obtain parameters specific for each species.

A hydrogen economy is an increasingly popular solution to lower global carbon dioxide emissions. Previous research has been focused on the economic conditions necessary for hydrogen to be cost competitive, which tends to neglect the effectiveness of greenhouse gas mitigation for the very solutions proposed. The holistic carbon footprint assessment of hydrogen production, distribution, and utilization methods, otherwise known as “well-to-wheels” carbon intensity, is critical to ensure the new hydrogen strategies proposed are effective in reducing global carbon emissions. When looking at these total carbon intensities, however, there is no single clear consensus regarding the pathway forward. When comparing the two fundamental technologies of steam methane reforming and electrolysis, there are different scenarios where either technology has a “greener” outcome.

Road noise and speech intelligibility are becoming ever more important, irrespective of the vehicle size, due to vehicle refinement as well as connectivity with mobile communication equipment. With better aerodynamic designs, development of refined powertrains, and a tectonic shift from I.C. engine to electric motors, road noise and wind noise will become more apparent to the customer and hence will become a priority for automakers to refine their vehicles. This paper describes the efforts undertaken to identify the road noise paths and develop countermeasures for a compact SUV vehicle. A hybrid test/CAE approach was followed to improve road noise performance of this vehicle. This effort involved developing tire CAE models from physical hardware and creating synthesized road-load input from data taken on roads.