Meta-heuristic algorithms in car engine design: a literature survey

Meta-heuristic algorithms are often inspired by natural phenomena, including the evolution of species in Darwinian natural selection theory, ant behaviors in biology, flock behaviors of some birds, and annealing in metallurgy. Due to their great potential in solving difficult optimization problems, meta-heuristic algorithms have found their way into automobile engine design. There are different optimization problems arising in different areas of car engine management including calibration, control system, fault diagnosis, and modeling. In this paper we review the state-of-the-art applications of different meta-heuristic algorithms in engine management systems. The review covers a wide range of research, including the application of meta-heuristic algorithms in engine calibration, optimizing engine control systems, engine fault diagnosis, and optimizing different parts of engines and modeling. The meta-heuristic algorithms reviewed in this paper include evolutionary algorithms, evolution strategy, evolutionary programming, genetic programming, differential evolution, estimation of distribution algorithm, ant colony optimization, particle swarm optimization, memetic algorithms, and artificial immune system

The global carbon budget 1959-2011

Accurate assessments of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere is important to better understand the global carbon cycle, support the climate policy process, and project future climate change. Present-day analysis requires the combination of a range of data, algorithms, statistics and model estimates and their interpretation by a broad scientific community. Here we describe datasets and a methodology developed by the global carbon cycle science community to quantify all major components of the global carbon budget, including their uncertainties. We discuss changes compared to previous estimates, consistency within and among components, and methodology and data limitations. CO2 emissions from fossil fuel combustion and cement production (EFF) are based on energy statistics, while emissions from Land-Use Change (ELUC), including deforestation, are based on combined evidence from land cover change data, fire activity in regions undergoing deforestation, and models. The global atmospheric CO2 concentration is measured directly and its rate of growth (GATM) is computed from the concentration. The mean ocean CO2 sink (SOCEAN) is based on observations from the 1990s, while the annual anomalies and trends are estimated with ocean models. Finally, the global residual terrestrial CO2 sink (SLAND) is estimated by the difference of the other terms. For the last decade available (2002–2011), EFF was 8.3 ± 0.4 PgC yr−1, ELUC 1.0 ± 0.5 PgC yr−1, GATM 4.3 ± 0.1PgC yr−1, SOCEAN 2.5 ± 0.5 PgC yr−1, and SLAND 2.6 ± 0.8 PgC yr−1. For year 2011 alone, EFF was 9.5 ± 0.5 PgC yr−1, 3.0 percent above 2010, reflecting a continued trend in these emissions; ELUC was 0.9 ± 0.5 PgC yr−1, approximately constant throughout the decade; GATM was 3.6 ± 0.2 PgC yr−1, SOCEAN was 2.7 ± 0.5 PgC yr−1, and SLAND was 4.1 ± 0.9 PgC yr−1. GATM was low in 2011 compared to the 2002–2011 average because of a high uptake by the land probably in response to natural climate variability associated to La Niña conditions in the Pacific Ocean. The global atmospheric CO2 concentration reached 391.31 ± 0.13 ppm at the end of year 2011. We estimate that EFF will have increased by 2.6% (1.9–3.5%) in 2012 based on projections of gross world product and recent changes in the carbon intensity of the economy. All uncertainties are reported as ±1 sigma (68% confidence assuming Gaussian error distributions that the real value lies within the given interval), reflecting the current capacity to characterise the annual estimates of each component of the global carbon budget. This paper is intended to provide a baseline to keep track of annual carbon budgets in the future

Risk Assessments for Chemical Stockpile Incinerators: Is the Supporting Guidance Adequate

The author identifies potential deficiencies in guidance used in the United States for risk assessments of chemical weapons incinerators

Nonlinear Unsteady Motions and NOx Production in Gas Turbine Combustors

Chiefly for improved efficiency, the trend to increasing use of gas turbine engines in stationary powerplants has been firmly established. The requirement for minimum NOx production has motivated operation as close as practically possible near the lean flammability limit, to reduce flame temperatures and consequently reduce formation of nitrogen oxides via the Zeldovich thermal mechanism. However, experience has shown that under these conditions, stability of the chamber is compromised, often leading to the presence of sustained oscillations in the combustor. That possibility raises the problem of the influence of oscillatory motions on the production of nitrogen oxides. Numerically calculating these influences for a complex geometry gas turbine combustor is too computationally expensive at this ?me. Nonlinear analytical methods making use of these influences are a promising direction for simplei ways to design and develop operational gas turbine combustors. However, this analysis needs results on which to base unsteady models of the interaction between nonlinear oscillations and species production within a gas turbine combustor. In this paper, two methods are explored briefly as an initial step. The first is based on a configuration of perfectly stirred and plug flow reactors to approximate the flow in a combustion chamber. A complete representation of the chemical processes is accommodated, but the geometry is simplified. The second is a full numerical simulation for a realistic geometry, but at this stage the chemistry is simplified

A High-Definition Spatially Explicit Modeling Approach for National Greenhouse Gas Emissions from Industrial Processes: Reducing the Errors and Uncertainties in Global Emission Modeling

Spatially-explicit (gridded) emission inventories (EIs) should allow us to analyse sectoral emissions patterns to estimate potential impacts of emission policies and support decisions on reducing emissions. However, such EIs are often based on simple downscaling of national level emissions estimate and the changes in subnational emissions distributions are not necessarily reflecting the actual changes driven by the local emissions drivers. This article presents a high definition,100m resolution bottom-up inventory of greenhouse gas (GHG) emissions from the industrial processes (fuel combustion activities in energy and manufacturing industry, fugitive emissions, mineral products, chemical industry, metal production, food and drink) that is exemplified on data for Poland. We propose an improved emission disaggregation algorithmthat fully utilizes a collection of activity data available at national/provincial level to the level of individual point and diffused (area) emission sources. To ensure the accuracy of the resulting 100m emission fields, the geospatial data used for mapping emission sources (point source geolocation and land cover classification) were subject to thorough human visual inspection.The resulting 100m emission field even hold cadastres of emissions separately for each industrial emission category, while we start with IPCC-compliant national sectoral GHG estimates that we made using Polish official statistics. We aggregated the resulting emissions to the level of administrative units such as municipalities, districts and provinces. We also compiled cadastres in regular grids and then compared them with EDGAR results. Quantitative analysis of discrepancies between both results revealed quite frequent misallocations of point sources used in the EDGAR compilation that considerably deteriorates high resolution inventories. We also propose a Monte-Carlo method-based uncertainty assessment that yields a detailed estimation of the GHG emission uncertainty in the main categories of the analysed processes. We found that the above mentioned geographical coordinates and patterns used for emission disaggregation have the greatest impact on overall uncertainty of GHG inventoriesfrom the industrial processes

Outside the Cap: Opportunities and Limitations of Greenhouse Gas Offsets

Explains the role of carbon offsets in providing flexibility and containing costs in a cap-and-trade program to limit greenhouse gas emissions. Recommends rigorous quantification, verification, and enforcement criteria to ensure the caps' integrity

Controlled autoignition of hydrogen in a direct-injection optical engine

Research into novel internal combustion engines requires consideration of the diversity in future fuels in an attempt to reduce drastically CO2 emissions from vehicles and promote energy sustainability. Hydrogen has been proposed as a possible fuel for future internal combustion engines and can be produced from renewable sources. Hydrogen’s wide flammability range allows higher engine efficiency than conventional fuels with both reduced toxic emissions and no CO2 gases. Most previous work on hydrogen engines has focused on spark-ignition operation. The current paper presents results from an optical study of controlled autoignition (or homogeneous charge compression ignition) of hydrogen in an engine of latest spark-ignition pentroof combustion chamber geometry with direct injection of hydrogen (100 bar). This was achieved by a combination of inlet air preheating in the range 200–400 °C and residual gas recirculated internally by negative valve overlap. Hydrogen fuelling was set to various values of equivalence ratio, typically in the range ϕ = 0.40–0.63. Crank-angle resolved flame chemiluminescence images were acquired for a series of consecutive cycles at 1000 RPM in order to calculate in-cylinder rates of flame expansion and motion. Planar Laser Induced Fluorescence (LIF) of OH was also applied to record more detailed features of the autoignition pattern. Single and double (i.e. ‘split’ per cycle) hydrogen injection strategies were employed in order to identify the effect of mixture preparation on autoignition’s timing and spatial development. An attempt was also made to review relevant in-cylinder phenomena from the limited literature on hydrogen-fuelled spark-ignition optical engines and make comparisons were appropriate

The European Carbon Market in Action: Lessons from the First Trading Period Interim Report

Abstract and PDF report are also available on the MIT Joint Program on the Science and Policy of Global Change website (http://globalchange.mit.edu/).The European Union Emissions Trading Scheme (EU ETS) is the largest greenhouse gas market ever established. The European Union is leading the world's first effort to mobilize market forces to tackle climate change. A precise analysis of the EU ETS's performance is essential to its success, as well as to that of future trading programs. The research program "The European Carbon Market in Action: Lessons from the First Trading Period," aims to provide such an analysis. It was launched at the end of 2006 by an international team led by Frank Convery, Christian De Perthuis and Denny Ellerman. This interim report presents the researchers' findings to date. It was prepared after the research program's second workshop, held in Washington DC in January 2008. The first workshop was held in Paris in April 2007. Two additional workshops will be held in Prague in June 2008 and in Paris in September 2008. The researchers' complete analysis will be published at the beginning of 2009.The research program “The European Carbon Market in Action: Lessons from the First Trading Period” has been made possible thanks to the support of: Doris Duke Charitable Foundation, BlueNext, EDF, Euronext, Orbeo, Suez, Total, Veolia

Characterisation of flame development with ethanol, butanol, iso-octane, gasoline and methane in a direct-injection spark-ignition engine

Research into novel internal combustion engines requires consideration of the diversity in future fuels that may contain significant quantities of bio-components in an attempt to reduce CO2 emissions from vehicles and contribute to energy sustainability. However, most biofuels have different chemical and physical properties to those of typical hydrocarbons; these can lead to different mechanisms of mixture preparation and combustion. The current paper presents results from an optical study of combustion in a direct-injection spark-ignition research engine with gasoline, iso-octane, ethanol and butanol fuels injected from a centrally located multi-hole injector. Methane was also employed by injecting it into the inlet plenum of the engine to provide a benchmark case for well-mixed ‘homogeneous’ charge preparation. Crank-angle resolved flame chemiluminescence images were acquired and post-processed for a series of consecutive cycles for each fuel, in order to calculate in-cylinder rates of flame growth and motion. In-cylinder pressure traces were used for heat release analysis and for comparison with the image-processing results. All tests were performed at 1500 RPM with 0.5 bar intake plenum pressure. Stoichiometric (ϕ = 1.0) and lean (ϕ = 0.83) conditions were considered. The combustion characteristics were analysed with respect to laminar and turbulent burning velocities obtained from combustion bombs in the literature and from traditional combustion diagrams in order to bring all data into the context of current theories and allow insights by making comparisons were appropriate