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1984-04-01
Technical Paper
840775
William J. O'Halloran
This paper discusses synchronization and loading of electrical generating systems. Both traditional, as well as state-of-the-art methods, are covered. The elements of synchronization are reviewed, and synchronizing equipment is described, including synchronizers with dead-bus closing circuits. Techniques for soft-loading, derating, and percent control of loading are also discussed.
1984-04-01
Technical Paper
840850
Tim F. Lee
Electric forklifts have historically been used in military applications such as unloading ammunition from storage areas due to a regulation which prohibited use of gasoline, diesel, or liquid propane gas (LPG) powered engines. This regulation has been changed to allow diesel powered forklifts if inside ambient air quality remains within safe levels. Diesel powered trucks are preferred over electric power for many military applications due to operational and support advantages. A new requirement for exhaust emissions from diesel powered forklift trucks has been developed by the Army for use in procurement of warehouse diesel trucks in the 4000–6000 lb capacity size. Future procurement by the Army of warehouse diesel forklifts in the 4000 - 6000 lb size will require that engines meet the new requirement for hydrocarbons (HC), carbon monoxide (CO), oxides of nitrogen (NOX), smoke and particulates.
1984-04-01
Technical Paper
840799
Wayne R. Anderson, Robert V. Burton
A family of cost-effective, high performance, electro-hydraulic servovalves has been developed for mobile and industrial machinery applications. The development was motivated by cost pressures on mobile and industrial closed loop servo system applications. The servovalve consists of a closed loop, pressure control pilot stage valve mated with a unique double spool design boost stage valve. It has been configured in both a flow control version and a pressure control servovalve version. Operating principles, performance characteristics, and general application are described.
1984-04-01
Technical Paper
840800
Kishor Patel
Responding to the need for affordable microprocessor-controlled digital valves manufactured and readily available in the United States, one manufacturer has designed a pulse-width modulated, two-stage proportional flow control valve for reliable man-in-the-loop control applications such as aerial lifts. The new PWM valve features simple on/off solenoids, no spool drift due to voltage or coil resistance changes, no spool silting or static friction, low leakage of pilot stage at neutral, continuous self flushing, and ease of interface with the microprocessor.
1984-04-01
Technical Paper
840786
William C. Pohl, Frederick J. Bulger
Propelled by the need for improved agricultural and construction productivity, industry has seen continued growth in the use of laser-based systems for blade control on earthmoving equipment. This growth has been supported by advances in micro-electronic and laser technology resulting in systems which offer increased performance and lower costs. To fully utilize the capabilities and benefits of this control technology, the hydraulic, electrical and mounting interfaces between the machine and laser control system need to be more compatible. The use of closed center hydraulics and allocation of adequate cab space for controls are two areas of machine design that could simplify installation, improve system performance and reduce cost.
1984-04-01
Technical Paper
840787
Phillip L. Nine, L. Akins
The use of electronic controls in mobile hydraulics has been increasing in the past few years. The introduction and acceptance of the proportional directional control valve has been the most important advancement in this technology. The proportional valve is used to control the propel pumps and motors alone with hydraulic load sensing to assure that forces and speeds are always available in the correct ratios. Examples of proportional control and load sensing arc described for several applications in mobile earthmoving equipment. Advantages of remote proportional control are demonstrated with ease of operation, flexibility, operator safety and energy conservation foremost in interest.
1984-04-01
Technical Paper
840789
Bernard R. Baranski
Molded blades on stamped steel spiders meet today's demand for low inertia, light weight, and lower cost cooling fans for construction and other heavy duty applications. Hybrid construction also permits use of wider blades for increased efficiency. Finite element modeling and extensive laboratory testing assure predictable durability.
1984-04-01
Technical Paper
840905
Dror Kopernik
The side stand is a common means of supporting a parked motorcycle. Motorcycle riders may, on occasion, forget to retract the stand before riding. The potential of an unretracted stand hitting the ground and interfering with the rider's control during a turn has been recognized for a long time. Different designs have been tried in an effort to reduce or eliminate the problem. Laboratory and road tests show the effects of geometrical design parameters on the retractability of side stands and define those parameters having the greatest influence.
1984-04-01
Technical Paper
840899
R. P. TOLOKAN, G. P. JARRABET, J. B. BRADY
Combustion chamber insulation techniques are being developed to improve the thermal efficiency of the internal combustion engine. Strain isolated ceramic coating systems are being evaluated to apply ceramic thermal barriers to metal engine components. A thorough understanding of the engine environment and the response of the coating system to that environment is needed to design durable coatings for engine use.
1984-04-01
Technical Paper
840890
James P. Arnold, Richard T. Sale
The military operational mission imposes stringent design and performance requirements for electric power sources which are not required of commercial counterparts. Developmental thrusts and specific programs are discussed which address these unique technical factors. Technical approaches being investigated include fuel cells, solid state power conditioners, and engine driven generators powered by diesel, gas turbine, Stirling, and spark ignition engines. Developmental goals require significant improvement in reliability, maintainability, mobility, and signature suppressions (aural and infrared), as well as provisions for NBC survivability.
1984-02-01
Technical Paper
840025
Charles W. Johnson, Jeffrey C. Huston
Pedal powered vehicles have been and are being built in many sizes and shapes. Due to the wide variety of possible configurations, the potential for lateral stability problems exists. This paper develops a basic analytical result for the lateral stability of rider/cycle systems. This result is algebraic in nature and can be evaluated quickly and easily. Several examples are given demonstrating the potential problems associated with changes in the rider/cycle parameters.
1984-02-01
Technical Paper
840024
R.A. Dennis
An increase in use of bicycles for short urban trips could help in a small but significant way to alleviate some present urban traffic problems. To encourage this goal an effective network of cycle-ways is needed on which bicycles and other compatible vehicles can be safely operated. An alternative bicycle type vehicle is proposed to overcome the disadvantages which deter some people from using bicycles. In this way it is hoped to encourage a greater potential use of cycle ways. This paper discusses the specifications for the vehicle and describes the design and development of prototypes.
1984-02-01
Technical Paper
840023
Douglas F. Schwandt
This paper describes the design development of two new bicycles for individuals with lower limb disability: an arm-powered bicycle and a tandem bicycle for disabled and able-bodied individuals to ride together. The tandem is a spinoff from the design of the single rider aria-powered bicycle. Both have been developed at the Palo Alto VA Rehabilitation Research and Development Center as part of a program to provide alternative recreational vehicles and equipment for people with disability. The functional features of each vehicle, and a descriptive discussion of the bicycle dynamics are presented.
1984-02-01
Technical Paper
840022
Ronald L. Huston
Governing equations of motion for a unicycle with a rider are presented. The system is assumed to be moving on a flat horizontal surface. Two specific cases are investigated: straight-line rolling and stationary positioning. Criteria for stability are explored. It is shown that stability can be obtained through active pedal monitoring by the rider.
1984-02-01
Technical Paper
840021
David Gordon Wilson, Richard Forrestall, Derek Henden
The dominant influence of racing regulations on the history of bicycles, and particularly of recumbent bicycles, is described. A new class of racing for human-powered vehicles, set up in 1974, brought about the present enthusiasm for recumbent bicycles. The development of the AVATAR 2000, originally designed to lessen injury risks in commuting, is described, together with modifications that, as the AVATAR BLUEBELL, led to its holding the world 200-m flying-start speed championship 1982-3. Paper closes with predictions of likely future developments.
1984-02-01
Technical Paper
840004
Kenneth J. Suda
Vegetable oils provide diesel engine performance similar to that obtained with diesel fuel, and this has been documented in many prior publications. Because they are potentially interchangeable with diesel fuel, interest has focused on vegetable oils as short-range alternate fuels. However, engine durability when burning vegetable oils may be adversely affected depending on the type of combustion system employed. Laboratory and field experimental tests have identified the prechamber engine as having the greatest short-range potential for using vegetable oil fuels. Performance and durability at low engine ratings are essentially the same as expected for operation on diesel fuel. However, at high engine ratings piston ring and cylinder liner wear are greater than expected for operation on diesel fuel.
1984-02-01
Technical Paper
840005
V.K. Duggal, T.-W. Kuo, F.B. Lux
The paper reviews the literature for methods of increasing fuel flexibility in diesel engines over a range of fuel properties representing alcohols to high viscosity diesels. It was conceived that the details of fuel-charge within the engine cylinder would help evaluate the requirements for multi-fuel engine design. It is therefore, attempted to model in-cylinder flows, fuel-air mixing and fuel property effects. The preliminary results of these calculations are presented.
1984-02-01
Technical Paper
840003
Yougoro Katoh, Tomoki Shimauchi, Tsutomu Nakagaki
Solvent Refined Coal (SRC II) was evaluated for its acceptability as alternate fuel for a spark assisted multifuel diesel engine which was modified to accept a spark plug in the swirl chamber. The objective of this study was to determine the effect of the use of SRC II on performance and emissions of the spark assisted swirl chamber diesel engine in comparison with diesel fuel operation. The results showed that SRC II could be used on the spark assisted diesel engine with engine performance comparable to that with conventional diesel fuel when the engine operating condition was optimum. However at other engine operating conditions large increase of unburned hydrocarbon and particulate emissions was found when operated with SRC II.
1984-02-01
Technical Paper
840227
V. K. Duggal, T. W. Kuo, T. Mukerjee, A. J. Przekwas, A. K. Singhal
The paper presents three-dimensional simulations of the in-cylinder processes in Direct Injection (DI) Diesel Engines. First, mathematical formulation is described with emphasis on physical models used for turbulence, interphase friction, evaporation and chemical reaction. Then, the results of 3D transient calculations of the two-phase fuel-air mixing and evaporation processes are presented. Four test cases have been considered to demonstrate the effects of changes in: a) fuel injector, b) computational grid, and c) initial air swirl velocity. Computed results show that each of these parameters has significant effect on the spread and evaporation of liquid fuel spray. The results of low and high air swirl cases are in qualitative agreement with published experimental observations. Finally, a test calculation of 3D, two-phase flow with evaporation and combustion is presented for demonstration purposes.
1984-02-01
Technical Paper
840228
C. Bassoli, G. Biaggini, G. Bodritti, G.M. Cornetti
Re-entrant bowls for high compression ratio heavy-duty turbocharged DI Diesel have been studied by the utilization of a two-dimensional axisymmetric model of the air motion and spray formation inside the cylinder. The trend of the air motion and spray pattern obtained by changing combustion chamber parameters are compared with the trend of the engine performance like smoke, fuel consumption, gaseous emissions and heat release rate. The results of this study strongly support the hypothesis that with reentrant-shaped combustion chambers an optimum level of the air fuel mixing is achieved at low values of the inlet port generated swirl.
1984-02-01
Technical Paper
840412
A.C. Alkidas
This study explored the relationships among particulate and carbon concentrations, and Bosch smoke number. The experiments were made on a 0.72-L, single-cylinder, divided-chamber, diesel engine. The Bosch smoke number correlates well with the carbon concentration and, to a lesser degree, with the particulate concentration. The theoretically based correlation established in this study between carbon concentration and Bosch smoke number agrees with several past correlations obtained in large, open-chamber diesel engines. Finally, no relationship was evident between the volatile concentration of particulates and the exhaust hydrocarbon concentration.
1984-02-01
Technical Paper
840413
J.M. Perez, F. Lipari, D.E. Seizinger
The Chemical Characterization Panel of the Coordinating Research Council Air Pollution Research Advisory Committee (CRC-APRAC) In house 1-64 Project Group (CAPI 1-64) conducted an extensive study of analytical methods for measuring diesel exhaust emissions. This report details the procedures developed for three of the non-regulated emissions. The first method, solvent extraction of particulate filters, recommends soxhlet extraction with either methylene chloride or toluene-ethanol, depending on the end use of the extract fraction. The second method involves collection of gas phase aldehydes in an acetonitrile-2, 4-dinitrophenylhydrazine solution followed by HPLC-UV analysis. The third method utilizes ion chromatography for analysis of particulate sulfate content. Round-robin testing by 18 Chemical Characterization Panel participants established precision and accuracy data that define the engineering applicability of the test methods.
1984-02-01
Technical Paper
840414
W. C. Eisenberg, D. Schuetzle, R. L. Williams
Two cooperative programs to measure polycyclic aromatic hydrocarbons (PAH) in extracts from diesel particulate emissions were conducted by project groups of the Coordinating Research Council's Air Pollution Research Advisory Committee. The use of a uniform analysis method by all participating laboratories gave better precision than the use of different methods selected by each participant. Results from eight laboratories gave relative standard deviations for nine PAH which ranged from 15 to 34% using the uniform method. These results show that this method for PAH provides adequate precision for diesel fuel-and-vehicle studies as well as for health effects assessment.
1984-02-01
Technical Paper
840419
S.R. Norris-Jones, T. Hollis, C.N.F. Waterhouse
The paper describes a programme of work carried out on a swirling direct injection diesel combustion system to establish the relative contribution of fuel burning from fully evaporated, droplet and ‘off the wall’ conditions to particulate formation and emissions. The high speed combustion photography and in-cylinder sampling techniques which were used are described. Results which enabled the formation and subsequent decay of particulate matter during the combustion process to be quantified are presented.
1984-02-01
Technical Paper
840421
Itaru Fukutani, Eiichi Watanab
In order to reduce the diesel idle knock, the effects of EGR on the idling characteristics were investigated on a passenger car-equipped with an EGR Idle Knock Reduction System developed for practical use. It was found that EGR was effective not only for reducing idle knock but also for decreasing fuel consumption, smoke density, exhaust emissions and engine vibration. Moreover, the practical range and possibility of the EGR Idle Knock Reduction System were found by clarifying the relationship between EGR, injection timing, cooling water temperature, noise level and fuel consumption.
1984-02-01
Technical Paper
840415
David P. Chock, Alan M. Dunker, Sudarshan Kumar
The annual mean diesel particulate concentrations in 1979 were estimated for four urban areas -- New York, Los Angeles, Washington, DC and Denver. These values were then compared with projections for the year 2000 under three different NOx emission scenarios. The particulate emission rates chosen for the three scenarios are best engineering estimates which include the implementation of advanced technology. It was found that diesel particulate concentrations remained about the same as the 1979 levels for the high NOx scenario, but doubled or more than doubled for the low NOx scenario. The low NOx scenario will also lead to a visibility deterioration of 5% or more compared to 1979 visibility. For all scenarios, the contributions of buses and heavy duty trucks to diesel particulate concentrations are comparable for all cities except Los Angeles, with a combined contribution of 65 to 85%.
1984-02-01
Technical Paper
840416
Terry L. Ullman, Charles T. Hare, Thomas M. Baines
Diesel engines are adjusted to manufacturers' specifications when produced and placed in service, but varying degrees of maintenance and wear can cause changes in engine performance and exhaust emissions. Maladjustments were made on two heavy-duty diesel engines typically used in buses in an effort to simulate some degree of wear and/or lack of maintenance. Emissions were characterized over steady-state and transient engine operation, in both baseline and maladjusted configurations. Selected maladjustments of the Cummins VTB-903 substantially increased HC, smoke and particulate emission levels. Maladjustments of the Detroit Diesel 6V-71 coach engine resulted in lower HC and NOX emission levels, but higher CO emissions, smoke, and particulate.
1984-02-01
Technical Paper
840417
Yasuhiro Fujiwara, Shoichi Fukazawa, Shigeru Tosaka, Tadashi Murayama
To clarify the formation processes of soot particulates in the combustion chamber, we sampled the gas during combustion in a precombustion chamber and a main chamber using an electromagnetic sampling valve, and made a gas analysis by gas chromatography, examined the soot concentration, and size distribution and dispersion of soot particulates with a transmission electron microscope. The following results were obtained: (1) In the prechamber soot particulates form at the period of rapid combustion in the initial stage rather than the end of the diffusion combustion. (2) Soot particulates which were formed in the prechamber were introduced to the main chamber, and a part of the soot particulates were burned. (3) Soot particulates formed at the initial stage of the combustion process exhibited a tendency to become smaller by oxidation. (4) If the oxygen concentration in the combustion chamber is above 5%, the combustion of soot particulates take place.
1984-02-01
Technical Paper
840418
Wolfgang Cartellieri, Peter Tritthart
Particulate mass emissions (US-EPA FTP75) of a variety of light duty diesel (IDI) production vehicles have been analysed for their content of organic insoluble and organic soluble fractions. The latter was further separated into lube oil and fuel particulate fractions by a gas chromatographic method which is described in the paper. This has provided the information to establish a database on the relative contributions of organic solubles and lube oil to both total particulates and total hydrocarbon (HC) emissions. As a result a target minimum lube oil particulate emission level has been defined to act as a guide line in engine development to minimize the contribution of the lube oil to total particulate matter. Additionally, HC and the various particulate fractions of IDI and DI high speed diesel engines are compared under steady state and transient operating conditions and their relative significance indicated.
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