Browse Topic: Steam engines

Items (41)
Measuring the dynamic parameters of liquid fragments generated in the near-field of atomizing sprays poses a significant challenge due to the random nature of the fragments, the instability of the spray, and the limitations of current measuring technology. Precise determination of these parameters can aid in improving the control of the atomization process, which is necessary for providing suitable spray structures with appropriate flow rates and droplet size distributions for various applications such as those used in heat engines. In piston and gas turbine engines, controlling spray characteristics such as penetration, cone angle, particle size, and droplet size distribution is crucial to improve combustion efficiency and decrease exhaust emissions. This can be accomplished by adjusting the structural and/or operating parameters of the fuel supply system. This article aims to measure the breakup length, spray cone angle, axial velocity, breakup time, and liquid sheet film thickness for a swirl air-blast atomizer used in a gas-steam engine. The measurement was conducted using a shadowgraph imaging system developed specifically for this study, consisting of a high-speed camera, a lens, and a light source. While lasers are commonly used as light sources in the literature, this study utilized a special LED high-speed pulse light generator, which is cheaper, easier to handle, and provides a more uniform background. Images were processed using a MATLAB code developed for this study. Although the breakup zone is naturally random and the breakup location significantly varies with time, the novel method developed in this study helps quantify critical parameters under different operating conditions.
Phung, Duoc V.Pham, Thin V.X. Pham, Phuong
Gustave de Ponton d'Amécourt, Gaspard Félix Tounachon and Guillaume Joseph Gabriel de La Landelle, dubbed the "Triumvirat Hélicoptèroidal" by French physicist Jacques Babinet, played indirect and subtle roles in the early history of the development of rotary-wing flight in the latter 19th century in Paris. Tournachon, adopting the professional name of 'Nadar', innovated aerial photography (from a balloon), forever changing the way people viewed the earth and significantly contributing to an enthusiasm for aviation, a term thought to have been coined by fantasy artist Gabriel de la Landelle. Landelle's appealing representations of just-possible future helicopter-ships caught the public fancy, also contributing to an awareness of such potential flight. Vicomte Gustave de Ponton d'Amécourt had begun working on a steam-powered coaxial rotary-wing design in 1853 - in the process, coining the word 'helicopter', and by 1863 a steam powered aluminum model had been produced by mechanic L. Joseph of Arras. Although the model aircraft failed, it represented the first use of aluminum in engine construction and was a milestone attempt to solve the weight/power issues necessary for manned flight that had been set forth by Sir George Caley, the "father of aerodynamics", in his 1809-10 series of papers under the collective title "On Aerial Navigation." These three, under the direction and promotion of Nadar, formed the 'Société d'Autolocomotion Aérienne' in 1862, the name of which was changed two years later to Société d'Aviation – the first organization to employ this term. These efforts resulting in a greatly increased public enthusiasm and awareness among the common people and notables of the time, and came to involve and inspire Jules Verne, who became the organization's secretary and promoter. Verne, in 1886, wrote Robur-le-Conquérant (Robur the Conqueror), known in English as The Clipper of the Clouds, the first helicopter novel, which would be read a young Russian boy and, much later, cited as a seminal inspiration – his name was Igor Sikorsky
Charnov, Bruce
Caterpillar believes that a total revamp of its track-type tractors should trim operating costs by 30 to 70%. As Caterpillar's track-type tractors enter their second century, the OEM has dramatically revamped its undercarriage technology. The company claims its SystemOne upgrades extend operating life, reduce operating costs, and improve ride characteristics. A project team created in 1999 redesigned the undercarriage from the ground up, something that Cat hadn't done since the 1970s. That effort yielded more than two dozen patents.
Costlow, Terry
Ignition and Combustion Process of a Steam Injected Diesel Engine (STID) Studied in a Constant Volume Rig2003-01-324910/27/2003
A new engine concept using direct injection of super heated steam in diesel engines is studied in a Constant Volume Bomb (CVB). The basic idea behind the Steam Injected Diesel Engine (STID) is to reduce the emissions of both particulates and NOx in addition to increasing the efficiency. By using air cooling and exhaust heat to generate the steam, the STID engine is believed to achieve an increase in the shaft efficiency and a substantial reduction of NOx and particulates emissions. This paper presents results from studies of the influence of superheated steam injection on the ignition delay. The justification for the study is the large amount of steam injected necessary for the STID engine and the need for studying the effect of superheated steam on engine operation. The background for the study is the massive steam injection necessary for the STID engine, and a detailed study is required when it comes to its effect on engine operation. Different ratios of air-to-steam mass and steam-to-fuel are selected in the range present in the Wasa 32 engine used for STID experiment at the Wärtsila factory in Finland. The pressure development is measured in these test series. The definition for ignition delay employed is the time from the triggering of the diesel injector until the pressure gradient exceeds dp/dt ≥2. The results indicate a surprisingly moderate dependence of the ignition delay on variations on both air-to-steam ratio and steam-to-fuel ratio in the Constant Volume Bomb (CVB). A small increase is found in the ignition delay as a function of the A/S-ratio. The steam tested was superheated at approximately 500 °C. This high temperature of the steam may explain the minor influence on the ignition and combustion process. Increasing the pressure and temperature inside the Constant Volume Rig at the time of diesel injection from 50 bar to 60 bar reduces the average ignition delay with 23 %.
Bysveen, MarieAlmås, Terje
Failure of materials from fatigue was not a problem before 1800. With the invention of the steam engine and the locomotives it powered, the industrial revolution started, and with it the advantages and frustrations in the use of rotating machinery. By 1850, when serious fatigue failures of locomotive axles were first experienced, a systems approach evolved for managing the interdisciplinary technologies that were required. It wasn't till about 1950 that the aircraft industry established systems management approaches for design to fatigue of aircraft structures.
Douglas, Lee
Emission Formation Characteristics of the Diesel Combustion Process and Estimated Future Development Trends7510022/1/1975
A review of the fuel consumption per capita and population trends is presented which suggests that any significant relaxation in diesel emission goals is undesirable. An analysis is then made of the chemical, thermodynamic and fluid dynamic factors which control the formation of nitric oxide, unburned hydrocarbon, carbon monoxide and exhaust smoke in diesel combustion. Based on this analysis it is hypothesized that a reduction in the quantity of fuel burned in diffusion flames and increased mixing rates of air and fuel vapor will significantly lower emission levels. It is suggested, therefore, that future trends in direct injection combustion development will need to incorporate increased fuel atomization and toroidal air motion to achieve the required favorable combustion conditions. A comparison is made of commercially acceptable, state-of-the-art diesel engines developed to meet low emission levels to allow an estimate of the potential improvements from combustion development. The comparison suggests that intense mixing and good fuel atomization, characteristic of the prechamber process, are the keys to lower emissions and can yield up to 40% reductions in HC + NO2 levels for the direct injection diesel combustion process. A forecast of future engine requirements is made and indicates that hybrid engines combining the diesel and Rankine cycles are feasible for heavy duty engine applications. The combination of the highly efficient diesel cycle and a reciprocating steam engine using diesel engine exhaust energy is a potentially efficient, low emission, socially acceptable prime mover.
Hoelzer, J. C.
The paper deals with reciprocating and rotary Rankine cycle engines using steam and organic fluids. It compares these theoretical engines to the present existing Otto cycle. The comparison considers size, torque, economy, emissions, response, maintenance, and reliability. Advantages and disadvantages of the various power systems are discussed and problem areas are identified.
Bjerklie, J. W.Sternlicht, B.
The story of Power Farming is the great saga of our times. It is a story of free enterprise, perseverance and endurance of the individual, of vision, idealism and cooperation among men, of the lightening of human toil and the release of millions of workers from farms to feed the ever hungry industrial revolution. By no means least, it is the story of producing food necessary to win two global wars, keep our allies alive and millions of the defeated enemy from starvation. FOREWARD By 1915, the Steam Traction Engine had attained its highest development. It was the forerunner, rather than the predecessor, of the farm tractor. The former was the instrument of expansion; the latter, the instrument of progress. The invention of the tractor, following by only sixteen years Otto's practical embodiment application of the Beau de Rochas power cycle to a heat engine, marked the advent of a new order - - the age of Power Farming. The pattern of progress follows that of the geometric progression; the scientist discovers, the engineer applies. Only the factor, never the formula, varies. Max Beerbaum has written “The past is a work of art, free of irrelevancies and loose ends”. This is an endeavor to write of these portentous times with the objectivity of time, rather than as a participant throughout much of the period; an effort to recreate past events after sufficient time has elapsed to recall them objectively, but not before the “irrelevancies and loose ends”, which are the price of history, have been obliterated. But the winds of change blow long and fierce. Tomorrow's greatest problem may well be that of continuing to feed those now enjoying the highest standard of living ever known and obliterate hunger and starvation from among those hundreds of millions whose abject misery threatens the very pillars of our society. At this time, absolute dates are but ripples on the oceans of time, and lose their meaning in a maze of semantics. It is not known, and is of little significance, whether recorded dates refer to invention, the completion of a pilot model, or of announced series production. In all cases, the author is governed by memory and the most credible published information.
Worthington, Wayne H.
COMPARISON of work capacity per unit mass and volume of different energy carriers shows that liquid hydrocarbons are superior to other energy sources. Solar and nuclear powerplants as well as their use in conjunction with a steam engine are examined in this paper. Suitability of an electric drive is discussed. Using a production 2-stroke diesel engine and its development forecast, a comparison is made of spark ignition, diesel, and gas turbine engines. The status of the free-piston engine turbine combination is reviewed.
Kyropoulos, Peter
GROWTH of mechanical transport since nineteenth-century days, when the steam engine was attached to ships and vehicles, is traced in this historical review. It was appropriately presented in observance of engineering achievements which have taken place during the past hundred years. The author records that development of the internal-combustion engine, replacing steam, led to the appearance of the automobile at the turn of the century. The horseless carriage increased travel speed, setting up immediate demands for more comfortable travel. Good roads, improved tires, new engine and body designs have followed without interruption for more than 50 years, ,with the supply of applied ideas never approaching public demands for still greater improvements. The author summarizes the situation as it exists today, giving many pertinent facts regarding the growth of the trucking industry, its relation to highway facilities and passenger-car travel, together with possibilities for future developments along better lines.
Bachman, B.B.
The High-Speed Diesel Engine as a Competitive Power Generator2800551/1/1928
HEREIN the author analyzes the Diesel oil-engine as a competitor of the steam engine and, more specifically, of the gasoline engine, in the stationary-power field and in the field of marine and land transportation. The two bases for judging the new as against the old are, first, suitability for the purpose, and, second, the cost of performing the required service. After reviewing other fields in which the oil-engine has shown its suitability, the author considers its suitability for automotive purposes. If it is equally suitable with the gasoline engine for motor-vehicles, that type of engine which shows lower cost for power will ultimately prevail; or, if the Diesel-engine cost is sufficiently lower, this type may be adopted for certain automotive uses even though it is somewhat inferior to the gasoline engine in suitability. The prospects of useful economic results from the automotive Diesel engine are so favorable, in the author's opinion, that almost any effort to perfect it and adapt it to the needs would be justified now. The most important reason for this conclusion is the adaptability of the engine to a great variety of liquid fuels. No reason exists for believing there will be any substantial difference in manufacturing cost if the Diesel engine is built by the same methods and in the same quantities as the gasoline engine; hence, first cost will be in proportion to weight in pounds per horsepower. Fixed charges will be in proportion for equal life and use. Experience to date indicates that the life of the Diesel engine should be equal to or longer than that of the gasoline engine, and that service costs need be no greater. In the matter of fuel consumption the oil-engine seems to be the more efficient, about in the ratio of 4 to 5; and this, with a cheaper fuel, means a large reduction in fuel expense per ton-mile. Development and adoption of the oil engine have been impeded by doubt of the ability to reduce its weight sufficiently, but, after analyzing the variables that fix the weight per horsepower, the author shows that an added weight of 30 per cent, to resist the maximum cylinder pressure for its somewhat longer period, is all the weight by which this type needs to exceed that of the gasoline engine. He even intimates that it is not beyond possibility that equality of weight may be obtained in four-cycle engines and perhaps better in the two-cycle type. Requirements as to torque, balance, flexibility and such matters are being proved by experience to be attainable, which confirms the analytical conclusion that these are only matters of engineering ingenuity and design. There remains the difficulty of metering the fuel and properly mixing it with the necessary quantity of air for proper combustion in high-speed engines. Several solutions of this problem have been advanced and there will be others. Hence it is to be expected that there will ultimately be as many automotive Diesel engines in use as there are now successful gasoline engines.
LUCKE, CHARLES EDWARD
Data regarding the condensation of water on engine-cylinder walls when running the engine at comparatively low temperatures were presented by the author in a previous paper to which he refers. These experiments showed that no water would be deposited when the cylinder-wall temperature exceeded 110 deg. fahr. but that the rate of deposition increased in direct proportion to the drop of temperature below 110 deg. fahr. His present paper describes laboratory tests of an engine equipped with a steam cooling-system, the object being to study the effect upon dilution of high cylinder-wall temperatures. The results show that a sharp reduction in dilution occurs as the boiling temperature is reached, and that the amount of dilution at temperatures of 212 deg. fahr., or more, is much less than would have been anticipated from the results obtained at temperatures below 212 deg. fahr. The author then points out that high cylinder-temperatures reduce dilution to a negligible quantity without introducing any apparent disadvantages. The fact that the elimination of dilution inevitably will produce lubrication troubles, due to the higher viscosity of oil which will prevail, is emphasized, and various methods by which oiling systems can be modified so as to approach nearer to the ideal condition are suggested.
CLAYDEN, A LUDLOW
The free, resilient, self-expanding, one-piece piston-ring is a product of strictly modern times. It belongs to the internal-combustion engine principally, although it is applicable to steam engines, air-compressors and pumps. Its present high state of perfection has been made possible only by the first-class material now available and the use of machine tools of precision. The author outlines the history of the gradual evolution of the modern piston-ring from the former piston-packing, giving illustrations, shows and comments upon the early types of steam pistons and then discusses piston-ring design. Piston-ring friction, the difficulties of producing rings that fit the cylinder perfectly and the shape of rings necessary to obtain approximately uniform radial pressure against the cylinder wall are considered at some length and illustrated by diagrams. The best material for piston-rings is stated to be cast iron; the average of 10 different analyses of satisfactory cast iron used for piston-rings is given; the piston-ring specification of one of the large motor-car manufacturers is presented; piston-ring joints and future design are considered; and a recommendation is made toward piston-ring standardization.
NILSON, L G
A new type of automotive engine should be the quest of all designing engineers. Investigation has revealed the fact that 68 per cent of all tractor engine troubles occur in magnetos, spark-plugs and carbureters, the accessories of the present-day automotive engine. Four-fifths of the fuel energy supplied is regularly wasted, yet the fuel is a liquid meeting severe requirements of volatility, etc., and is already becoming scarce and costly. In an airplane, fuel is carried by engine power. In ocean-going cargo vessels it increases available revenue space. It is at once clear that for purely practical reasons the question of fuel economy, no less than the question of the nature of the fuel, becomes momentous. What fuel will do is entirely a question of what process it is put through in the engine; in what way combustion is turned into power. In the paper the physical processes underlying the conversion of combustion energy into power are discussed, together with the various methods for producing the pressure differences needed for the operation of ordinary heat engines. The author states both the theoretical and the practically attainable energy utilizations of engines and turbines of the compressor, explosion and evaporation types. Improvements are found to be obtainable in all three types and some suggestive lines of work are pointed out. Among these the compressor engine and the steam powerplant offer interesting possibilities in competition with the work already done by the Brayton, Kraus and Armengand-Lemale engines. In connection with the investigation of electrical combustion batteries, the author asks whether it would be possible to use the combustion process with our ordinary fuels to deliver electric current in a primary battery, and what the fuel utilization of such a battery would be. It is known that from 1910 to 1912 Baur, Taitelbaum and Ehrenberg, in Germany, succeeded in combining such fuel batteries and obtaining electromotive forces close to those theoretically possible.
NORMAN, C A
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