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Combustion Engines (combustion + engine)

Distribution by Scientific Domains

Engineering	66%
Chemistry	16%

Kinds of Combustion Engines

internal combustion engine

Selected Abstracts

Thermoeconomic modeling of micro-CHP (micro-cooling, heating, and power) for small commercial applications

INTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 9 2008
Alan Moran
Abstract The increasing demand for electrical power as well as energy for heating and cooling of residences and small commercial buildings is a growing worldwide concern. Micro-cooling, heating, and power (micro-CHP), typically designated as less than 30,kW electric, is decentralized electricity generation coupled with thermally activated components for residential and small commercial applications. The number of combinations of components and parameters in a micro-CHP system is too many to be designed through experimental work alone. Therefore, theoretical models for different micro-CHP components and complete micro-CHP systems are needed to facilitate the design of these systems and to study their performance. This paper presents a model for micro-CHP systems for residential and small commercial applications. Some of the results that can be obtained using the developed model include the cost per month of operation of using micro-CHP versus conventional technologies, the amount of fuel per month required to run micro-CHP systems, the overall efficiency of micro-CHP systems, etc. A case study is used to demonstrate differences in the system performances of micro-CHP systems driven by a natural gas internal combustion engine and a diesel engine. Some of the results show that both systems have similar performance and that system total efficiencies in cooler months of up to 80% could be obtained. Also, modeling results show that there is a limit in fuel price that economically prevents the use of CHP systems, which is $11 MBTU,1 for this specific case. Copyright © 2008 John Wiley & Sons, Ltd. [source]

Adaptive sliding mode control of air,fuel ratio in internal combustion engines

INTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL, Issue 6 2004
Jason S. Souder
Abstract A simplified model of an internal combustion engine is used to derive a sliding mode control law. Adaptive update laws are derived for two fueling parameters that describe fuel flow into the cylinders, and a third parameter that describes air flow into the cylinders. The update laws allow the sliding mode control gain, which is usually increased to overcome model uncertainty, to be reduced. This improves the tracking performance of the sliding mode controller in the presence of the feedback time delays. The parameter update laws are modified to bound the parameter values and allow all three parameter update laws to run simultaneously. The effect of the sampling rate on the adaptive sliding mode controller performance and air,fuel ratio biasing via gain selection are also addressed. Copyright © 2004 John Wiley & Sons, Ltd. [source]

Radical innovation in a small firm: a hybrid electric vehicle development project at Volvo Cars

R & D MANAGEMENT, Issue 4 2010
Hans Pohl
The potential paradigmatic shift in technology from the internal combustion engine to electric propulsion via hybrid electric vehicles (HEVs) has been addressed by most automakers, and has produced very different outcomes. This paper uses the framework of core capabilities to discuss how the small automaker, Volvo Cars, made substantial progress in its HEV development using an approach based on limited resources and a low risk. A comparison with Toyota's successful but very resource-demanding Prius project reveals some factors contributing towards rapid development in a context of limited resources, including focused project objectives, tight collaboration with suppliers of the new technologies, reuse of existing technologies and an unaggressive, bottom-up approach to change the firm's values and norms and other core capability dimensions. This paper provides an empirical illustration of how a small company in a mature industry worked with radical innovation in a development project drawing on the combination of organizational slack, entrepreneurial employees and an extensive use of external (knowledge) suppliers. [source]

Direct use of vegetable oil and animal fat as alternative fuel in internal combustion engine

BIOFUELS, BIOPRODUCTS AND BIOREFINING, Issue 2 2008
Pinaki Mondal
Abstract Gradual depletion of world petroleum reserves and the impact of environmental pollution of increasing exhaust emissions lead to the search for a suitable alternative fuels for diesel engines. The substitution of conventional fuels (gasoline, diesel) by renewable biofuels is considered a potential way to reduce pollution and to support the sustainable development of a country. Direct use of vegetable oil and animal fat is a promising alternative to solve these problems. An exhaustive review of the experiments in this area, carried out by several researchers in last three decades, is presented here. Different problems associated with the direct use of vegetable oil and animal fat and potential solutions from both public and private sectors are discussed. Some engine manufacturers have started to launch full-warranty engines with vegetable oil as fuel. It is expected that the competitive engine market will witness more intense research, resulting in the launch of more vegetable-oil engines with full warranties. The steep rise in food prices in recent years is concerning policy-makers and has raised the old ,food vs fuel' debate. It has been concluded that vegetable oil can probably only substitute small to medium portions of petroleum-based fuel due to future severe land-usage competition from food sector. This calls for intense research initiatives into the production of suitable fuel from non-edible vegetable oil, grown in wasteland. In this regard, genetic engineering may prove to be extremely effective in developing ,designer fuel'. © 2008 Society of Chemical Industry and John Wiley & Sons, Ltd [source]

Increasing business value with landfill gas-to-energy projects: Regulations and requirements for stationary internal combustion engines

ENVIRONMENTAL QUALITY MANAGEMENT, Issue 4 2009
Mario G. Cora
First page of article [source]

Numerical simulation of gaseous fuel injection: A new methodology for multi-dimensional modelling

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS, Issue 6 2010
Luca Andreassi
Abstract The use of natural gas (instead of liquid or solid fuels) is nowadays drawing an increasing interest in many applications (gas turbines, boilers, internal combustion engines), because of the greater attention to environmental issues. To facilitate the development of these applications, computer models are being developed to simulate gaseous injection, air entrainment and the ensuing combustion. This paper introduces a new method for modelling the injection process of gaseous fuels that aims to hold down grid requirements in order to allow the simulation also of other phenomena, like combustion or valve and piston motion, in reciprocating internal combustion engines. After a short overview of existing models, the transient jet model and the evaluation of inflow conditions are described in detail. Then a basic study of the grid effects on the jet evolution is presented. The model is updated and validated by comparing numerical results with available experimental data for two different operating conditions: a subsonic and a supersonic under-expanded case. The model demonstrates to be fast enough to be used in a multi-dimensional code and accurate enough to follow the real gas jet evolution. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Adaptive sliding mode control of air,fuel ratio in internal combustion engines

Greenhouse gas reduction potential of advanced traffic control

JOURNAL OF ADVANCED TRANSPORTATION, Issue 3 2000
Abdulkader Alkadry
Reducing greenhouse gas (GHG) emissions from transportation in the context of the climate change issue and the associated Kyoto Agreement of 1997 is a challenge. Since urban transportation is a major contributor to greenhouse gases, measures are required to reduce these emissions. Given that during peak periods, road vehicles propelled by petroleum fuel-based internal combustion engines produce a high level of GHG emissions due to stop and go operations, measures to improve traffic flow can play an effective mitigation role. This paper describes a simulation-based methodology and a case study for the quantification of GHG emission reduction owing to advanced traffic control systems. [source]

Functional properties of microstructured cylinder liner surfaces for internal combustion engines

LUBRICATION SCIENCE, Issue 4 2005
R. Golloch
Abstract Internal combustion engines are still of major importance as propulsion systems. To fulfil future market and legislative demands it is necessary to improve engine performance, reduce fuel consumption, and limit exhaust emissions. Mechanical and thermodynamic losses, wear, and the emissions caused by lubricating oil combustion are principally influenced by the tribological behaviour of the piston assembly. The trend towards compact engines with high power densities and increased thermomechanical loads increases the importance of this tribological system and requires new approaches. One promising possibility is the utilisation of liner surfaces with specially machined microstructures. This paper describes a comparison between a conventional liner surface and a laser-structured liner as regards their tribological behaviour. Measurements of wear as well as of oil film thickness and friction force in operation have been carried out. The results show better tribological behaviour for the laser-structured liner surface than for the conventional plateau-honed surface. This leads to lower fuel consumption and less wear. [source]

A method of measuring oil consumption by labelling with radioactive bromine

LUBRICATION SCIENCE, Issue 3 2000
H. Zellbeck
Abstract A method of determining the oil consumption rate of combustion engines is presented. It is based on labelling the individual oil fractions of engine oil with radioactive bromine isotope82 Br and on the quantitative absorption of radioactive bromine compounds in the exhaust gas in an aqueous solution of nitric acid and silver nitrate. The advantages of this method are that the oil that is consumed in the exhaust gas can be directly measured, without the fluctuating amounts of oil in the sump influencing the result, and the behaviour of the individual components of the oil in the consumption process can be determined. The test is quick, only twenty minutes being required to detect oil consumption at one operating point; and with a single labelling, the oil consumption at a great number of working engine points can be measured 82 Br has a short half-life of only 36 h, so that compliance with radiation protection measures is inexpensive and investigations can be carried out using a conventional testing device. As part of the research project, a study was made of the influence of different base oil types, with and without polymer additives, on consumption. Results showed that Noack evaporation loss correlated with oil consumption only with boiling fractions of exactly the same base oil, and not with different, in particular synthetic, base oils; that polymer additives (VI improvers) significantly reduced the rate of oil consumption; and that the polymer additive and the type of base oil both had more influence on oil consumption than viscosity. [source]

Selected ion flow tube mass spectrometry (SIFT-MS) for on-line trace gas analysis

MASS SPECTROMETRY REVIEWS, Issue 5 2005
David Smith
Abstract Selected ion flow tube mass spectrometry (SIFT-MS) is a new analytical technique for the real-time quantification of several trace gases simultaneously in air and breath. It relies on chemical ionization of the trace gas molecules in air/breath samples introduced into helium carrier gas using H3O+, NO+, and O precursor ions. Reactions between the precursor ions and trace gas molecules proceed for an accurately defined time, the precursor and product ions being detected and counted by a downstream mass spectrometer, thus effecting quantification. Absolute concentrations of trace gases in single breath exhalation can be determined by SIFT-MS down to ppb levels, obviating sample collection and calibration. Illustrative examples of SIFT-MS studies include (i) analysis of gases from combustion engines, animals and their waste, and food; (ii) breath and urinary headspace studies of metabolites, ethanol metabolism, elevated acetone during ovulation, and exogenous compounds; and (iii) urinary infection and the presence of tumors, the influence of dialysis on breath ammonia, acetone, and isoprene, and acetaldehyde released by cancer cells in vitro. Flowing afterglow mass spectrometry (FA-MS) is briefly described, which allows on-line quantification of deuterium in breath water vapor. © 2004 Wiley Periodicals, Inc., Mass Spec Rev 24:661,700, 2005 [source]