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Iron powders were warm compacted in air utilizing liquid tin as a lubricant. Liquid tin functioned effectively as a lubricant over the entire range of compacting pressures examined (207-414 MPa). Under equivalent conditions, at compacting pressures of 414 MPa (30 tsi), liquid tin was shown to have lubricity comparable to inc stearate. Liquid tin was found to be most effective as a lubricant when present in low concentrations (less than 5%, by weight) and when subjected to high compacting pressures. Lubricant removal, prior to sintering, was unnecessary since solution of tin in iron caused no apparent impairment to strength. Solution rates of tin in iron were sufficiently rapid to be capable of saturating iron with tin at 1121°C within 30 minutes. Grain growth and shrinkage during sintering were enhanced by the presence of tin.

An experimental study was carried out on visualization of liquid phase temperature distributions in high-pressure diesel sprays impinging on a heated wall. Naphthalene/TMPD-exciplex fluorescence method and pyrene-excimer fluorescence method were utilized for the thermometry. The sprays were injected into a high-pressure and high-temperature gaseous environment. The nozzle hole diameter was 0.100 mm or 0.139 mm. The results showed that cool pockets were formed at the tip and in the impinging part of the sprays. The spray for the nozzle with 0.100 mm hole was heated up faster near the nozzle than for the nozzle with 0.139 mm hole.

Propane is one alternative fuel which is already widely available. Its use as a transporation fuel has largely been confined to spark ignition engines, however. This paper reports on an investigation into liquid propane injection as a means for fueling diesel engines. A single-cylinder CFR cetane rating engine was used to carry out the experimental work. The fuel system was revised to ensure that propane remained liquified in the fuel injection pump and injector. Since propane has a very low cetane number, some means of ignition must be provided. Two means of ignition were evaluated in this investigation, diesel pilot injection and a continuously operating glow plug. Tests were carried out at compression ratios of 19:1, 22:1 and 25:1 and at engine speeds of 1200, 1500 and 1800 rpm for each of the two ignition methods. The results are similar for the same test conditions.

Experimental spray tip penetrations obtained from a large-bore medium-speed optical diesel engine were compared to CFD simulations. The optical spray results are unique as they are obtained from a running large-bore (200mm) diesel engine. The experimental spray tip penetration measurements were obtained during the early spray development period when the spray evaporation had not yet reached the quasi steady-state phase. The CFD simulations were conducted in both static chamber environment and in engine conditions. The fuel injection boundary conditions were obtained from 1-D simulations. Within the error margins associated with the experimental and computational data, relatively good accuracy was obtained between measured and simulated spray tip penetration. It was also observed that it is very important to have accurate fuel injection mass flow rate data. This was observed after a sensitivity analysis was made for the injection duration and fuel mass quantity.

A conversion to LPG of a SI engine that was originally carbureted gasoline is reported in this work. The conversion was implemented on a 1988 Skoda 120L with a 1174cc rear engine. The conversion to run on Liquefied Petroleum Gas (LPG) was carried out using a programmable Engine Control Unit (ECU) that operated a single point fuel injection system. The LPG used was a commercially available mixture of butane and propane. The fuel injection system was designed to operate with the LPG in the liquid state. A circulating pump was used to maintain availability of LPG in liquid state at the inlet to the fuel injector. This made possible the use of similar fuel injection parts as in a gasoline system. Injection of the fuel in the liquid state provided cooling to the intake air as measured during driving of the vehicle and also on chassis dynamometer runs.

Liquid and vapor envelopes of sprays from a multi-hole fuel injector operating under closely-spaced double-injection conditions were investigated using a combination of high-speed schlieren and Mie scattering imaging. The effects of mass split ratio and dwell time between injections on liquid and vapor penetration have been investigated under engine-like pressures and temperatures. For the conditions evaluated, the results indicate that closely-spaced double-injection generally reduces liquid and vapor penetration.

Air-assist fuel sprays have been investigated experimentally with exciplex laser-induced fluorescence visualization and computationally with the KIVA-3 code. The exciplex-fluorescence technique provided simultaneous but distinct cross-sectional images of the liquid and vapor fuel distributions under simulated light-load conditions in both an atmospheric-pressure test rig and in a motored two-stroke engine. The computations resolved the flow through the injector passages upstream of and around the poppet, and included the effects of aerodynamic drop breakup, drop collisions and vaporization. Both the measurements and the calculations show that the fuel initially emerges from the injector as a hollow-cone jet. This two-phase jet collapses downstream as entrainment of air produces a low-pressure region beneath the poppet.

An optically-accessible single cylinder small-bore HSDI diesel engine equipped with a Bosch common-rail injection system is used to study the effects of multiple injection. High-speed video is used to study the injector and spray behavior. Laser-induced exciplex fluorescence is used to obtain simultaneous liquid and vapor fuel distributions within the combustion chamber, with tetradecane-TMPD-naphthalene as the base fuel-dopant combination. Significant liquid impingement is seen in the single main injection case, while evidence of liquid impingement is seen only in the first stage of the multiple injection case. No appreciable liquid impingement is seen for the second stage of the multiple injection case. Vapor is seen throughout the jet cross-section regardless of the injection parameters. The majority of the vapor is confined to the bowl region in the single injection case while evidence of vapor is seen outside of the bowl for the multiple injection case.

An optically accessible single cylinder small-bore HSDI diesel engine equipped with a Bosch common-rail injection system was used to study the effects of multiple injection strategies on the in-cylinder combustion processes. The operating conditions were considered typical in the metal engine under moderate load conditions. In-cylinder pressure traces are used to analyze heat release characteristics. The combustion modes transit from the Homogeneous Charge Compression Ignition (HCCI)-like combustion mode to conventional diesel combustion by changing injection parameters. The whole cycle combustion process was visualized through a high-speed digital video camera and the combustion images clearly show the combustion mode transition. Laser-Induced Exciplex Fluorescence (LIEF) technique was used to obtain simultaneous liquid and vapor fuel distributions within the combustion chamber, with tetradecane-TMPD-naphthalene as the base fuel-dopant combination.

An optically-accessible single-cylinder compression-ignition two-stroke research engine equipped with dual-injection system, image acquisition, and control system have been designed to acquire two-dimensional images of the pilot and main diesel fuel sprays. The engine construction permits illumination of the sprays by a thin sheet of laser light from a pulsed Nd:YAG laser frequency tripled to operate at the ultraviolet wavelength of 355 nm. The liquid fuel was decane with TMPD-naphthalene dopant dispersed in it. Upon ultraviolet excitation by the pulsed laser, liquid fuel regions fluoresced with a spectrum centered at the wavelength of 380 nm, while vapor regions fluoresced with a spectrum centered at 470 nm. This approach, called Exciplex technique, was applied to permit simultaneous acquisition of the liquid and vapor fuel regions in the cup-in- head geometry of the combustion chamber.

Increased worldwide environmental pressure has made it necessary for polyurethane foam processors to eliminate chlorinated products, such as chlorofluorocarbons (CFCs) and methylene chloride, and other volatile organic compounds (VOCs) from their production atmosphere; these products have historically been utilized by the polyurethane industry to perform the vital function of expanding agents for foam. As a result, the industry has been undergoing an intensive search for viable, readily available, and safe alternatives to these products. These alternative products have been labeled ABAs (alternative blowing agents). The oldest and simplest known blowing agent for polyurethanes is carbon dioxide (CO2), a nonhazardous chemical, capable of expanding foams down to a very low density.

THIS paper gives a brief resumé of the development of the Rolls-Royce Kestrel engine and then analyzes the requirements of the high-performance engine of the future, developing at least 1500 b.hp. and operating on fuels of high knock ratings. The problems investigated include those of engine form, fuels, detonation, waste-heat disposal, cooling drag, cooling medium, and the mechanical and operational features. Conclusions deduced from the arguments are: (a) Compression ratios, charge density, and rotational speeds will need to increase and, therefore, cylinder bores and strokes will decrease; it may be necessary to adopt the sleeve-valve type. (b) The arrangement of the engine will tend to multithrow crankshafts with more than two pistons per crankpin.

Under Department of Energy sponsorship, the Los Alamos Scientific Laboratory is presently road testing a U.S. intermediate sized automobile adapted to liquid-hydrogen fuel. The overall project objective is to document a general experience base as a point of departure for future development. A semiautomatic fueling station developed by the Deutsche Forschungs- und Versuchsanstalt für Luft- und Raumfahrt (DFVLR) of the Federal Republic of Germany is being used to service (refuel) the experimental vehicle. The DFVLR also provided the 150-ℓ (39.6-gal.) cryogenic liquid-hydrogen storage tank mounted in the trunk compartment and the dashboard fuel gauging system. The V-6 turbocharged engine was converted to hydrogen operation by the Billings Energy Corporation. Both the container and the engine modifications represented state-of-the-art technology when the program began.

The maximum axial penetration distance of liquid phase fuel (i.e., the “liquid length”) in an evaporating diesel spray was investigated over a wide range of conditions using Mie-scattered light imaging. The parameters varied in the investigation included: the injection pressure, the orifice diameter and aspect ratio, the ambient gas temperature and density, and the fuel volatility and temperature. The experiments were conducted in a constant-volume combustion vessel with extensive optical access. Fuels were injected with an electronically controlled, common-rail diesel fuel injector. The dominant trends observed were: (a) Liquid length decreases linearly with orifice diameter and approaches zero as the orifice diameter approaches zero. (b) Injection pressure has no significant effect on liquid length. (c) Liquid length decreases with increasing ambient gas density or temperature, but with a declining sensitivity to each one as they increase.

During summertime, some in-vehicle components can reach very high temperatures, in particular because of solar radiation through windows. The liquid-filled double glazing (LFDGW) window permit the solar gain because of its absorbing properties and consequently permit to maintain the window temperature. The impact of such a window on in-vehicle temperatures is evaluated with the Therm_Cab® software. Results indicate that the temperatures of the in-vehicle component are reduced significantly.

A body of listening test techniques which produces consistant rankings of sound systems is presented. Sufficient detail is generated in the course of the prescribed listening evaluation to direct engineering changes to the system. A two dimensional weighting system (performance and usage) is used to determine a single-number rating.

The 1990's have witnessed widespread proliferation of inexpensive, inertia-loaded chassis dynamometers. Previously, chassis dynos were not accessible to the general public. Thanks to this proliferation, there is now a core audience of knowledgeable auto enthusiasts who have chassis dyno results for their cars, but little understanding of the difference between these results, SAE net HP and actual power delivered to ground. This audience consists of trend leaders and early adopters, the customers most sought after by the OEMs. This paper derives the loss sources present in these tests, and illustrates the difference between the different reference frames for power measurement.

Literate and illiterate drivers were compared on the basis of their driving histories and characteristics of their crashes. Illiterate drivers had significantly more crashes and convictions than the general driving public. When compared to matched control drivers, illiterate drivers still had more convictions and crashes. Their crashes tended to be in older vehicles that were more likely to have reported defects. They were also more likely to be driving trucks. Recommendations are presented for a comprehensive coordinated approach to encouraging acquisition of literacy skills which in turn may be reflected in improved driving performance.

Dual fuel operating strategy offers great opportunity to reduce emissions like particulate matter and NOx from compression ignition engine and use of clearer fuels like natural gas. Dual-fuel engines have number of potential advantages like fuel flexibility, lower emissions, higher compression ratio, better efficiency and easy conversion of existing diesel engines without major hardware modifications. In view of energy depletion and environmental pollution, dual-fuel technology has caught attention of researchers. It is an ecological and efficient combustion technology. This paper summarizes a review of recent research on dual-fuel technology and future scope of research. Paper also throws light on present limitations and drawbacks of dual-fuel engines and proposed methods to overcome these drawbacks. A parametric study of different engine-operating variables affecting performance of diesel-CNG dual-fuel engines vis-à-vis base diesel operation is also summarized here.

A literature and experimental study was done to create an overview of the behavior of gasoline combusted in a CI-engine. This paper creates a first overview of the work to be done before implementing this Gasoline Compression Ignition concept in a multi-cylinder engine. According to literature the gasoline blend will have advantages over diesel. First the shorter molecular chain of the gasoline makes it less prone to soot. Second the lower density gives the gasoline a higher nozzle exit speed resulting in better mixing capabilities. Third the lower density and higher volatility lets the spray length decrease. This lowers the chance of wall-impingement, but creates worse mixing conditions looking from a spray point of view. The CO and HC emissions tend to increase relative to operation with diesel fuel, NOx emissions largely depend on the choice of combustion strategy and could be influenced by the nitrogen bound to the EHN molecule that is used as an ignition improver.