Modeling of Flame Propagation and Energy Conversion Rates in SI Engines

1983 ◽  
Author(s):  
R. Maly ◽  
E. Wagner ◽  
G. Ziegler
Keyword(s):  
Energy Conversion ◽  
Flame Propagation ◽  
Conversion Rates ◽  
Si Engines

scholarly journals Non-Stoichiometric Redox Active Perovskite Materials for Solar Thermochemical Fuel Production: A Review

Catalysts ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 611 ◽  
Author(s):  
Anita Haeussler ◽  
Stéphane Abanades ◽  
Julien Jouannaux ◽  
Anne Julbe
Keyword(s):  
Carbon Dioxide ◽  
Solar Energy ◽  
Energy Conversion ◽  
Operating Conditions ◽  
Solar Fuel ◽  
Fuel Production ◽  
Concentrated Solar Energy ◽  
Redox Active ◽  
Conversion Rates ◽  
Wide Range

Due to the requirement to develop carbon-free energy, solar energy conversion into chemical energy carriers is a promising solution. Thermochemical fuel production cycles are particularly interesting because they can convert carbon dioxide or water into CO or H2 with concentrated solar energy as a high-temperature process heat source. This process further valorizes and upgrades carbon dioxide into valuable and storable fuels. Development of redox active catalysts is the key challenge for the success of thermochemical cycles for solar-driven H2O and CO2 splitting. Ultimately, the achievement of economically viable solar fuel production relies on increasing the attainable solar-to-fuel energy conversion efficiency. This necessitates the discovery of novel redox-active and thermally-stable materials able to split H2O and CO2 with both high-fuel productivities and chemical conversion rates. Perovskites have recently emerged as promising reactive materials for this application as they feature high non-stoichiometric oxygen exchange capacities and diffusion rates while maintaining their crystallographic structure during cycling over a wide range of operating conditions and reduction extents. This paper provides an overview of the best performing perovskite formulations considered in recent studies, with special focus on their non-stoichiometry extent, their ability to produce solar fuel with high yield and performance stability, and the different methods developed to study the reaction kinetics.

On the use of a tabulation approach to model auto-ignition during flame propagation in SI engines

2011 ◽  
Vol 88 (12) ◽  
pp. 4968-4979 ◽  
Author(s):  
Vincent Knop ◽  
Jean-Baptiste Michel ◽  
Olivier Colin
Keyword(s):  
Flame Propagation ◽  
Auto Ignition ◽  
Si Engines

Thermal and Electrical Energy Transport and Conversion in Nanoscale Electron Field Emission Processes

2002 ◽  
Vol 124 (5) ◽  
pp. 954-962 ◽  
Author(s):  
T. S. Fisher ◽  
D. G. Walker
Keyword(s):  
Energy Conversion ◽  
Field Emission ◽  
Energy Transport ◽  
Exchange Process ◽  
Electrical Energy ◽  
Electron Field Emission ◽  
Operational Parameters ◽  
Transfer Rates ◽  
Conversion Rates ◽  
Electron Field

This paper considers the theory of electron field emission from nanoscale emitters with particular focus on thermal and electrical energy transport. The foundational theory of field emission is explored, and a model is presented that accounts explicitly for the energy band curvature produced by nanoscale tip emitters. The results indicate that the inclusion of band curvature strongly influences the energetic distribution of electrons for emitter radii less than 50 nm. The energy exchange process between emitted and replacement electrons is shown to allow high local energy transfer rates that can be exploited in direct thermal-to-electrical energy conversion processes. The dependence of energy conversion rates on material and operational parameters is demonstrated. Throughout the paper, opportunities for further research involving nanoscale heat transfer, materials development, and modeling are highlighted.

scholarly journals Symbiosis extended: exchange of photosynthetic O2 and fungal-respired CO2 mutually power metabolism of lichen symbionts

2019 ◽  
Vol 143 (3) ◽  
pp. 287-299 ◽  
Author(s):  
Marie-Claire ten Veldhuis ◽  
Gennady Ananyev ◽  
G. Charles Dismukes
Keyword(s):  
Electron Transport ◽  
Energy Conversion ◽  
Water Oxidation ◽  
Photosynthetic Electron Transport ◽  
Fluorescence Yield ◽  
Consecutive Series ◽  
Low Light ◽  
Conversion Rates ◽  
Algal Photosynthesis ◽  
Flavoparmelia Caperata

AbstractLichens are a symbiosis between a fungus and one or more photosynthetic microorganisms that enables the symbionts to thrive in places and conditions they could not compete independently. Exchanges of water and sugars between the symbionts are the established mechanisms that support lichen symbiosis. Herein, we present a new linkage between algal photosynthesis and fungal respiration in lichen Flavoparmelia caperata that extends the physiological nature of symbiotic co-dependent metabolisms, mutually boosting energy conversion rates in both symbionts. Measurements of electron transport by oximetry show that photosynthetic O2 is consumed internally by fungal respiration. At low light intensity, very low levels of O2 are released, while photosynthetic electron transport from water oxidation is normal as shown by intrinsic chlorophyll variable fluorescence yield (period-4 oscillations in flash-induced Fv/Fm). The rate of algal O2 production increases following consecutive series of illumination periods, at low and with limited saturation at high light intensities, in contrast to light saturation in free-living algae. We attribute this effect to arise from the availability of more CO2 produced by fungal respiration of photosynthetically generated sugars. We conclude that the lichen symbionts are metabolically coupled by energy conversion through exchange of terminal electron donors and acceptors used in both photosynthesis and fungal respiration. Algal sugars and O2 are consumed by the fungal symbiont, while fungal delivered CO2 is consumed by the alga.

scholarly journals Effect of Sisal Nanoparticles on Single Cylinder Spark Ignition Engine Combustion

2020 ◽  
Vol 8 (6) ◽  
pp. 1027-1032
Keyword(s):  
Flame Propagation ◽  
Combustion Process ◽  
Fuel Mixture ◽  
Spark Ignition ◽  
Combustion Efficiency ◽  
Spark Ignition Engine ◽  
Single Cylinder ◽  
Engine Combustion ◽  
Si Engines ◽  
Propagation Velocities

Turbulence is an important parameter to be considered for effective combustion inside a cylinder. Heat transfer inside the cylinder affects the combustion process. Insufficient turbulence leads to incomplete combustion, resulting in pollution. Effective flame propagation leads to higher combustion rates in SI engines which in turn requires enough turbulence. Effective combustion efficiency can be achieved through higher flame propagation velocities. In the present work an attempt has been made to enhance the turbulence inside the cylinder of a single cylinder spark ignition engine by injecting solid nanoparticles into the air fuel mixture.

Fundamental Study on Effects of Residual Fuel Droplets on Flame Propagation in SI Engines

2003 ◽  
Author(s):  
Hiroshi Nomura ◽  
Toyohiro Hamasaki ◽  
Ikue Kawasumi ◽  
Yasushige Ujiie ◽  
Jun'ichi Sato
Keyword(s):  
Flame Propagation ◽  
Fundamental Study ◽  
Fuel Droplets ◽  
Si Engines
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