Search results for "COMBUSTION"
showing 10 items of 232 documents
Detailed Combustion Analysis of a Supercharged Double-Fueled Spark Ignition Engine
2021
The main goal of researches in the field of automotive engineering is to obtain a large-scale implementation of low- or zero-emissions vehicles in order to substantially reduce air pollution in urban areas. A fundamental step toward this green transition is represented by the improvement of current internal combustion (IC) engines in terms of fuel economy and pollutant emissions. The spark ignition (SI) engines of modern light-duty vehicles are supercharged, down-sized, and equipped with direct injection. Gaseous fuels, such as liquefied petroleum gas (LPG) or natural gas (NG), proved to be a valid alternative to gasoline in order to reduce pollutant emissions and increase fuel economy. In …
Kardar–Parisi–Zhang scaling in kinetic roughening of fire fronts
1999
Abstract We show that the roughening of fire fronts in slow combustion of paper [7] follows the scaling predictions of the Kardar–Parisi–Zhang equation with thermal noise. By improved experimental accuracy it is now possible to observe the short-time and short-range correlations of the interfaces. These do not adhere to any standard picture, and in particular, do not seem to be related to any of the existing models of front propagation in the presence of quenched disorder.
Hybrid Energy Storage for Underground Mining EV
2021
One of the main concerns when it comes to contributions to the carbon footprint is the consumption of fuel by vehicles, more specifically that of mining vehicles. One solution to this problem is replacing the combustion engine vehicles with electric vehicles. This also poses the problem of low power density. This paper proposes a solution of using supercapacitors and hybrid capacitors with the aim of investigating how they can affect the performance of electric vehicles. For this purpose, a background of fuel consumption and alternative solutions to the problem are discussed, a prototype was designed and built. It was found that when supercapacitors and hybrid capacitors were used in combin…
In-Cylinder Heat Transfer Determination Using Impulse Response Method with a Two-Dimensional Characterization of the Eroding Surface Thermocouple
2021
Heat transfer from the cylinder of internal combustion engines has been studied for decades, both in motored and fired configurations. Its understanding remains fundamental to the optimization of engine structures and sub-systems due to its direct effect on reliability, thermal efficiency and gaseous emissions. Experimental measurements are usually conducted using fast response surface thermometers, which give the instantaneous cylinder surface temperature. The transient component of heat flux through the cylinder wall was traditionally obtained from a spectral analysis of the surface temperature fluctuation, whereas the steady-state component was obtained from Fourier's law of conduction. …
Fluidized Bed Combustion and Gasification of Fossil and Renewable Slurry Fuels
2021
This article provides a comprehensive review of the state of the art and more recent developments of the thermochemical treatments of slurry fuels in fluidized beds (FB). The review focuses on FB combustion and gasification of slurry fuels based on coal, biomass, sludge, and wastes from industry, agriculture, and the civil sector. The investigations at research and industrial levels over the last decades are presented and discussed, highlighting the adopted technological solutions, the results in terms of feasibility and efficiency, and the perspectives of future development. The different behavior between bubbling and circulating beds was addressed, in particular the optimal choice dependi…
Modelling the Interaction between Air Pollutant Emissions and Their Key Sources in Poland
2021
The main purpose of this study is to investigate the relationships between key sources of air pollutant emissions (sources of energy production, factories which are particularly harmful to the environment, the fleets of cars, environmental protection expenditure) and the main environmental air pollution (SO2, NOx, CO and PM) in Poland. Models based on MLP neural networks were used as predictive models. Global sensitivity analysis was used to demonstrate the significant impact of individual network input variables on the output variable. To verify the effectiveness of the models created, the actual data were compared with the data obtained through modelling. Projected courses of changes in t…
Electric Mobility in Portugal: Current Situation and Forecasts for Fuel Cell Vehicles
2021
In recent years, the growing concern for air quality has led to the development of sustainable vehicles to replace conventional internal combustion engine (ICE) vehicles. Currently, the most widespread technology in Europe and Portugal is that of Battery Electric Vehicles (BEV) or plug‐in HEV (PHEV) electric cars, but hydrogen‐based transport has also shown significant growth in the commercialization of Fuel Cell Electric Vehicles (FCEV) and in the development of new infrastructural schemes. In the current panorama of EV, particular attention should be paid to hydrogen technology, i.e., FCEVs, which is potentially a valid alternative to BEVs and can also be hybrid (FCHEV) and plug‐in hybrid…
Active colloidal suspensions: Clustering and phase behavior
2014
We review recent experimental, numerical, and analytical results on active suspensions of self-propelled colloidal beads moving in (quasi) two dimensions. Active colloids form part of the larger theme of active matter, which is noted for the emergence of collective dynamic phenomena away from thermal equilibrium. Both in experiments and computer simulations, a separation into dense aggregates, i.e., clusters, and a dilute gas phase has been reported even when attractive interactions and an alignment mechanism are absent. Here, we describe three experimental setups, discuss the different propelling mechanisms, and summarize the evidence for phase separation. We then compare experimental obse…
Reprocessed polylactide: Studies of thermo-oxidative decomposition
2012
The combustion process of virgin and reprocessed polylactide (PLA) was simulated by multi-rate linear non-isothermal thermogravimetric experiments under O2. A complete methodology that accounted on the thermal stability and emission of gases was thoroughly developed. A new model, Thermal Decomposition Behavior, and novel parameters, the Zero-Decomposition Temperatures, were used to test the thermal stability of the materials under any linear heating rate. The release of gases was monitored by Evolved Gas Analysis with in-line FT-IR analysis. In addition, a kinetic analysis methodology that accounted for variable activation parameters showed that the decomposition process could be driven by …
Upgrade of citrus waste as a biofuel via slow pyrolysis
2015
Abstract Slow pyrolysis (200–650 °C) experiments on citrus residues (orange peel waste “OP” and lemon peel waste “LP”) were carried out in lab scale fixed bed batch reactor. Bio-oil and bio-char obtained by thermal degradation are more stable, more homogeneous and higher energy content fuels when compared to the parent feedstock. Thermogravimetric analysis (TGA) showed higher stability of LP waste, which appears related to the higher lignin content . Mass and energy yields of solid and liquid products (i.e., char and oil) were measured to determine the effects of peak temperature on feedstock. A linear correlation between Gross Calorific Value (GCV), peak temperatures and mass loss (ML) all…