CERN Document Server

We analyze the driven resonantly coupled Jaynes-Cummings model in terms of a quasienergy approach by switching to a frame rotating with the external modulation frequency and by using the dressed atom picture. A quasienergy surface in phase space emerges whose level spacing is governed by a rescaled effective Planck constant. Moreover, the well-known multiphoton transitions can be reinterpreted as resonant tunneling transitions from the local maximum of the quasienergy surface. Most importantly, the driving defines a quasienergy well which is nonperturbative in nature. The quantum mechanical quasienergy state localized at its bottom is squeezed. In the Purcell limited regime, the potential well is metastable and the effective local temperature close to its minimum is uniquely determined by the squeezing factor. The activation occurs in this case via dressed spin flip transitions rather than via quantum activation as in other driven nonlinear quantum systems such as ...

Energy Technology Data Exchange (ETDEWEB)

This work demonstrate the gasoline volatility influence, at T 10%, T 50% and T 90% distillation points, on the dynamic performance of Otto cycle engines equipped with fuel sequential electronic injection system, by using test standard procedures in dynamometer. For each distillation points three value ranges were established, giving the rise of 27 different gasoline mixtures. The effects of variation in each point on consumption, power and acceleration were verified.

CERN Document Server

By using a laser and maser in tandem, it is possible to obtain laser action in the hot exhaust gases involved in heat engine operation. Such a "quantum afterburner" involves the internal quantum states of working gas atoms or molecules as well as the techniques of cavity quantum electrodynamics and is therefore in the domain of quantum thermodynamics. As an example, it is shown that Otto cycle engine performance can be improved beyond that of the "ideal" Otto heat engine.

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This paper presents an investigation into the feasibility and potential advantages of a small scale Miller cycle natural gas engine for applications such as domestic combined heat and power systems. The Miller cycle engine is compared to a standard Otto cycle engine using cycle analyses and multidimensional simulation, and basic engine design implications are discussed. It is found that the Miller cycle engine has a potential for improved fuel efficiency, but at the cost of a reduced power to weight ratio. A fuel efficiency advantage of 5{yields}10% compared to a standard Otto cycle engine appears possible, however it is stated that further investigations, in particular into the topic of engine friction, are required in order to validate the findings. (author)

Energy Technology Data Exchange (ETDEWEB)

The increase of the compression ratio of Otto carburator engines up to epsilon = 14 was investigated by Audi in its research department at Neckarsulm. The results are presented in three partial reports. Part one describes the Audi fuel method and demonstrates the effects of the main parameters. Part two shows the influence of the current on the combustion by the help of a new measuring method developed by the Institut fuer Physikalische Elektronik at Stuttgart University. Part three provides a theoretical analysis of the data gained in the investigations.

British Library Electronic Table of Contents (United Kingdom)

An Otto cycle engine with internal and external irreversibilities of friction and heat leakage, in which the heat transfer between the working fluid and the environment obeys linear phenomenological heat transfer law [q ?? ?(T ?1)], is studied in this paper. The optimal piston motion trajectory for maximizing the work output per cycle is derived for the fixed total cycle time and fuel consumed per cycle. Optimal control theory is applied to determine the optimal piston trajectories for the cases of with and without piston acceleration constraint on each stroke and the optimal distribution of the total cycle time among the strokes. The optimal piston motion with acceleration constraint for each stroke consists of three segments, including initial maximum acceleration and final maximum decel...

Energy Technology Data Exchange (ETDEWEB)

The majority of Brazilian big cities served by conventional railroad systems with routes starting in the center of the URBIS, destinate them the long distances transport of passengers and cargo. Actually, these systems are being transformed to become commuter trains which join a great capacity of transportation to a much lower costs of implantation than subway ones. The most important characteristic of this train, when talking about energy consumption, is the possibility of using different kinds of explosion engines from three cycles: Diesel, mixed (Diesel + Natural Gas), and Otto moved by natural gas, besides the traditional electric traction. The use of natural gas in Otto cycle engines shows itself competitive from the point of view of investments, operational costs and environmental preservation. (author). 10 refs., 1 fig

Energy Technology Data Exchange (ETDEWEB)

Equations are derived to permit calculation of the work required for the isentropic compression of a two phase fuel-air mixture. Methanol evaporation during compression is shown to substantially reduce compression work and thereby improve cycle efficiency and maximum power. Effects of evaporative cooling in the intake manifold are calculated. 14 refs.

Energy Technology Data Exchange (ETDEWEB)

Various engine concepts that are in the race to be the dominant bus-engine type five years from now were reviewed. Three types of engines, the Otto cycle (CNG and propane), diesel and DME (dimethyl ether) received most of the attention. Emission standards, engine size and reliability are the main demands on bus engines. Each of these engine concepts were reviewed against these criteria. In terms of emission standards (as measured by the EEV emission limits) Otto cycle engines have the advantage since they are currently in production. Advanced diesel technology is on the prototype level, but not yet in production. DME-engines are still on the testbed, not in the demonstration stage and much less in the production stage. Otto cycle engines also have the most experience with EEV emission limits. Among the Otto-cycle engines, propane-fuelled engines appear to have the upper hand since propane is very ...

Energy Technology Data Exchange (ETDEWEB)

Propane and Butane are the main components of LPG as an automotive fuel in the eighties. The worldwide supply of gas will expand, the infrastructure necessary for the transport, storage and distribution of the extra quantities will be supplied. A percentage of 5-10% of the total German gasoline consumption is propable. LPG is an excellent fuel for Otto-cycle-engines, not only from an environmental point of view. Experience gathered with LPG in car engines will be reported on as well as on developments concerning the application field.

Energy Technology Data Exchange (ETDEWEB)

The FIAT company in Brazil tested the use of biogas for combustion in otto cycle engines, both stationary and Not stationary, and proved that technically it is a good option in substitution of gasoline. The work presents the changes in the motor for biogas use and compares it with alcohol motors for power and consumption. 18 figs.

Energy Technology Data Exchange (ETDEWEB)

A methanol car means a car driven with a fuel that has part of or the whole of the gasoline or kerosene replaced with methanol. Fuel methanol is abundantly available, relatively easy to transport and store and has few environmental pollutants in its exhaust gas. Its octane value is high, but ignitionability is not good due to its low cetane value. It is good for Otto cycle engines, but not adequate for diesel cycle engines. As a technological problem, the point is ignitionability and development of Otto type methanol engines ahead of that of diesel type methanol engines. Evaluation of methanol cars is internationally high and its development is done vigorously, but there are also problems including a short continuous travel distance due to the low heating value of methanol. Although methanol cars are deemed to be most promising for commercialization among cars using alternative fuel, it is necessary to cope systematically and collectively in ...

Energy Technology Data Exchange (ETDEWEB)

This paper describes a system for biogas conversion to electric power and heat by using a micro turbine and three Otto cycle engines. The benefit of the energy from a treatment process residue aims the improvement of the global performance of the system, reducing the the emission of the greenhouse gases and contributing to the global energetic efficiency of the sewage treatment station and the basic sanitation in Brazil.

Energy Technology Data Exchange (ETDEWEB)

Using gasoline as an example of additives for cold start improvement, fuel vapor composition of methanol-gasoline mixtures, fuel evaporation rate in consideration of temperature drop due to heat of fuel evaporation, air fuel ratio, stoichiometric air fuel ratio and excess air ratio of fuel vapor were calculated. The mixture formation of methanol-gasoline mixtures at low temperature in otto cycle engines was studied. Van Laar's empirical formula was used to estimate the partial pressure of high-percentage methanol blends. It was found that the most part of fuel vapor is occupied by gasoline, even when a small amount of gasoline is added to methanol resulting to an extremely small excess air ratio. It is obvious that this vapor pressure adjustment using gasoline is the dominant factor for improvement in cold startability. (10 figs, 1 tab, 10 refs)

British Library Electronic Table of Contents (United Kingdom)

Oxygenated fuels increase fuel consumption due to their low enthalpy of combustion; however, their high antiknock index renders them suitable for use in engines with a high compression rate, increasing their thermal yield. This study evaluated the performance of biorenewable oxygenated fuels (ethanol and isoamyl alcohol) and partially renewable fuels (ETBE: ethyl tert-butyl ether, TAEE: tert-amyl ethyl ether and di-TAE: di-tert-amyl ether) with high degree of purity and in mixtures with automotive gasoline, based on tests with Otto cycle engines. Among the oxygenated fuels evaluated here, di-TAE was found to present the best characteristics of performance, both individually and in mixtures with gasoline.

CERN Document Server

The unavoidable irreversible losses of power in a heat engine are found to be of quantum origin. Following thermodynamic tradition a model quantum heat engine operating by the Otto cycle is analyzed. The working medium of the model is composed of an ensemble of harmonic oscillators. A link is established between the quantum observables and thermodynamical variables based on the concept of canonical invariance. These quantum variables are sufficient to determine the state of the system and with it all thermodynamical variables. Conditions for optimal work, power and entropy production show that maximum power is a compromise between the quasistatic limit of adiabatic following on the compression and expansion branches and a sudden limit of very short time allocation to these branches. At high temperatures and quasistatic operating conditions the efficiency at maximum power coincides with the endoreversible result. The optimal compression ratio varies from the square ...

Energy Technology Data Exchange (ETDEWEB)

Fhe ECOTRONIC system developed by Bosch und Pierburg System oHG is an electronic system for mixture formation for Otto-cycle engines complying with high operational requirements. Engineers incorporated electronic control of the quantity of mixture and mixture enrichment for supplementary functions into a reliable, low-cost system, which will also comply with future requirements concerning fuel consumption, emissions and driveability. The author of the present article reduces the carburetor down to its basic systems, explains how supplementary functions were converted from mechanical to either open or closed-loop electronic control, and describes the newly developed actuators, the control unit making use of digital technology, and the results achieved.

Energy Technology Data Exchange (ETDEWEB)

In the 80's, because of the oil crisis, the Natural Gas (NG) appeared as a fuel with a great potential for Diesel replacement in Heavy Duty Vehicles. At that time, PETROBRAS with other companies have developed partial conversion technologies from Diesel to NG, known as 'Dual Fuel'. Engine dynamometer and vehicle bus tests have been developed to verify its technical and economical viability. Because of several factors, the Dual Fuel Program did not advance and the experience was interrupted. At the same time, other experiences using NG Otto Cycle bus engines, manufactured in Brazil, have been conducted, mainly at Sao Paulo, nevertheless, without expansion. Currently, factors as increase of the NG converted light vehicles fleet; the NG excess in the National Market, which has contributed to the NG distribution net expansion; the Environmental Legislature in vigor, that continuously determine lower emission limits; the government interest in ...

International Nuclear Information System (INIS)

This guide explained the requirements for Off-Road Compression Ignition Engine Emission Regulations established under the Canadian Environmental Protection Act. The regulations are enforced by Environment Canada, which authorizes and monitors the use of the national emissions mark. The regulations prescribe standards for off-road engines that operate as reciprocating, internal combustion engines, other than those that operate under characteristics similar to the Otto combustion cycle and that use a spark plug or other sparking device. The regulations apply to engines that are typically diesel-fuelled and found in construction, mining, farming and forestry machines such as tractors, excavators and log skidders. Four different types of persons are potentially affected by the regulations: Canadian engine manufacturers; distributors of Canadian engines or machines containing Canadian engines; importers of engines or machines for the purpose of sale; and persons not in ...

Energy Technology Data Exchange (ETDEWEB)

The object of this report is to assemble information on and describe the situation for the development of hybrid vehicles and various alternatives within this field of development. In the report the description is concentrated mainly on the combination of combustion engine and electric battery, which is the most common combination in present day hybrid vehicles. In order to take a glimpse into the future even the combination of fuel cells and electric battery is described. The light duty electric hybrid vehicles which have been developed up to now are mainly parallel hybrids. If the development of hybrid systems takes place it will most certainly concern light duty vehicles which will come to be parallel hybrids equipped with an Otto or a diesel engine, depending on what the manufacturers wish to back. In the report the use of series hybrid vehicles is estimated to be limited to heavy-duty hybrid vehicles. Hybrids will not be likely to be relevant for heavy-duty ...

Energy Technology Data Exchange (ETDEWEB)

The proceedings of a workship of researchers and potential users of decomposed method fuel for Otto cycle engines are presented. The purpose of the meeting was to review the state-of-the-art. Proponents for its use state that by using exhaust waste heat to decompose the methanol, the resulting gaseous fuel constituents have more energy content than that in the original liquid. The drawbacks include the unapplicability during engine warmup and the fraction of automobile duty cycle related thereto, the reduced volumetric efficiency associated with any gaseous fuel, and the tradeoffs between improved thermal efficiency and reduced power output with lean fuel mixtures. There has always been a dilemma as to whether a decomposed methanol system is a variation on the application of methanol, of hydrogen, or both. However, the more immediate issue is whether use of methanol is liquid, decomposed or dual form is the most cost effective and energy efficient way to use it. ...

Energy Technology Data Exchange (ETDEWEB)

A procedure is described for modeling the choices made in urban American households among personal vehicles on the bases of cost, passenger capacity, and engine technology, and it projects those preferences to the year 1990 and 2000. The results of this disaggregate technique are used by the other predictive research tasks undertaken by Argonne National Laboratory in a project entitled Technology Assessment of Productive Conservation in Urban Transportation (TAPCUT). The vehicle preferences reported here furnish data for the overall TAPCUT objective of forecasting the probable effects of energy conservation policies in transportation. In our projections, vehicles with standard spark-ignition (Otto-cycle) engines continue to dominate automobile holdings and new car purchases in either of two socioeconomic scenarios under any of three settings (an existing policy set and two alternative conservation strategies). From 1990, small cars (seating four or fewer ...

Energy Technology Data Exchange (ETDEWEB)

This proceedings volume comprises 17 papers on the following subjects: Methane hydrates, compounds of gas and water; Compressed air stroage gas turbine power plants / Scheduled application for load levelling between varying wind power production and power demand; Modern pumped storage power stations in the GW range - the PSW Goldisthal example; Lead batteries - new developments and future applications; Alkaline battery systems for hybrid electric road vehicles; Lighium systems and their applications; Zinc/air cells; Hydrogen storage - metal hydride storage, compressed gas storage, LNG storage; Carbon nanofibres for hydrogen storage; Double-layer condensers - technology, cost, perslpectives; Supercondensers in motor vehicles; Superconducting magnetic energy stores; Flywheel storage - status report; Decentralized energy storage in the European integrated supply grid - the EU project DISPOWER; Intercontinental integration of power supply - perspectives of full-scale power supply on the ...