The Impact of Spark Discharge Pattern on Flame Initiation in a Turbulent Lean and Dilute Mixture in a Pressurized Combustion Vessel

2013 ◽  
Vol 6 (1) ◽  
pp. 435-446 ◽  
Author(s):  
Anqi Zhang ◽  
Khanh Cung ◽  
Seong-Young Lee ◽  
Jeffrey Naber ◽  
Garlan Huberts ◽  
...  
Keyword(s):  
Spark Discharge ◽  
Discharge Pattern ◽  
Pressurized Combustion ◽  
The Impact ◽  
Dilute Mixture ◽  
Combustion Vessel

scholarly journals The influence of impurities on the operation of selected fuel ignition systems in combustion engines

2016 ◽  
Vol 65 (2) ◽  
pp. 349-360 ◽  
Author(s):  
Sebastian Różowicz ◽  
Szymon Tofil
Keyword(s):  
Spark Discharge ◽  
Combustion Engines ◽  
Discharge Energy ◽  
Ignition System ◽  
System A ◽  
Spark Plug ◽  
Different Types ◽  
The Impact ◽  
Influence Of Impurities

Abstract The paper attempts to determine the impact of fuel impurities on the spark discharge energy and the wear of the spark plug electrode. Spark plugs were analyzed in two typical configurations of the ignition system. A number of tests were conducted to determine the wear of the spark plug electrode exposed to different types of impurities. The spark discharge energy for new and worn spark plugs was determined through calculation.

Experimental and Numerical Study of Flame Kernel Formation Processes of Propane-Air Mixture in a Pressurized Combustion Vessel

2016 ◽  
Vol 9 (3) ◽  
pp. 1494-1511 ◽  
Author(s):  
Xiucheng Zhu ◽  
Lorenzo Sforza ◽  
Tejas Ranadive ◽  
Anqi Zhang ◽  
Seong-Young Lee ◽  
...  
Keyword(s):  
Numerical Study ◽  
Formation Processes ◽  
Flame Kernel ◽  
Pressurized Combustion ◽  
Combustion Vessel

Evaluation of a Spark Discharge Particulate Matter Sensor in a Turbocharged Diesel Engine

2007 ◽  
Author(s):  
David P. Gardiner ◽  
William D. Allan ◽  
Marc LaViolette
Keyword(s):  
Particulate Matter ◽  
Diesel Engine ◽  
Oxygen Sensor ◽  
Spark Discharge ◽  
Exhaust Pipe ◽  
Engine Exhaust ◽  
Exhaust Temperature ◽  
Sensor Temperature ◽  
Diagnostic Applications ◽  
The Impact

This paper describes an experimental study of a Particulate Matter (PM) sensor that is intended for on-board control and diagnostic applications in diesel engines. The sensor measures the exhaust PM concentration based upon changes in the voltage waveform of a repetitive, low energy spark discharge. The sensor is electrically heated to prevent carbon fouling from diesel soot and to control its operating temperature. Earlier versions of the sensor were installed directly in the engine exhaust pipe like an Exhaust Gas Oxygen sensor. It was determined that the output of the PM sensor was sensitive to temperature as well as PM concentration, and variations in exhaust temperature made it difficult to maintain the sensor at a constant temperature. In the present study, the sensor was mounted in an electrically heated chamber and a portion of the engine exhaust was bypassed through the chamber. This made it possible to improve the stability of the sensor temperature, thereby reducing the sensitivity of the PM indication to changes in exhaust temperature as the engine load was varied. The PM sensor has been evaluated using a Caterpillar Model 3126 turbocharged 6-cylinder medium duty diesel engine. Small changes in load were used to create minor variations in exhaust PM levels. The PM levels were measured using an AVL 415S smoke meter. Experimental results are presented showing the correlation between the PM sensor signal and the reference PM measurements and the impact of speed and load variations on the correlation.

scholarly journals Effect of changes in climate variables on hydrological regime of Chenab basin, western Himalaya

2021 ◽  
Author(s):  
Sonia Grover ◽  
Shresth Tayal ◽  
Richa Sharma ◽  
Stein Beldring
Keyword(s):  
Climate Change ◽  
River Discharge ◽  
Hydrological Regime ◽  
Western Himalaya ◽  
Discharge Pattern ◽  
Ice Melt ◽  
Rcp 8.5 ◽  
Basin Water ◽  
Seasonal Discharge ◽  
The Impact

Abstract In high altitude, scarcely gauged basins, climate change impact assessment on river discharge is important for sustainable management of water resources. These basins are sources for irrigation, hydropower generation in the region. Expected changes in precipitation and temperature can affect the basin's hydrological regime which will have consequential impacts on the dependent sectors. For quantifying the impacts of major climatic variables on hydrological processes, this paper examined bias-corrected GCM outputs coupled with a hydrological model – HBV for Chenab basin. Trend analysis shows that precipitation would decrease after the short-term period and temperature is expected to increase throughout the century. Simulated river discharge is expected to increase throughout the 21st century under both RCP 4.5 and RCP 8.5 scenarios. It is also observed that there would be a shift in seasonal discharge pattern with increased pre- and post-monsoon contributions. Increase in snow and ice melt contribution to the overall discharge is also expected and would range between 50 and 59% until 2100. This study concluded that expected increase in discharge volume coupled with shift in seasonal discharge pattern would impact the basin water management and thus it is important to consider the impact of climate change on hydrological regime of basins.

Formation of Lunar Craters and Bright Rays as a Result of Meteorite Impacts

1962 ◽  
Vol 14 ◽  
pp. 415-418
Author(s):  
K. P. Stanyukovich ◽  
V. A. Bronshten
Keyword(s):  
Explosive Charge ◽  
The Moon ◽  
Meteorite Impacts ◽  
The Earth ◽  
Lunar Craters ◽  
The Impact

The phenomena accompanying the impact of large meteorites on the surface of the Moon or of the Earth can be examined on the basis of the theory of explosive phenomena if we assume that, instead of an exploding meteorite moving inside the rock, we have an explosive charge (equivalent in energy), situated at a certain distance under the surface.

The Geosciences Applied to Lunar Exploration

1962 ◽  
Vol 14 ◽  
pp. 169-257 ◽  
Author(s):  
J. Green
Keyword(s):  
Lunar Surface ◽  
Probable Mechanism ◽  
Point Of View ◽  
Lunar Exploration ◽  
Geological Model ◽  
Apply Geophysics ◽  
Surface Features ◽  
The Impact

The term geo-sciences has been used here to include the disciplines geology, geophysics and geochemistry. However, in order to apply geophysics and geochemistry effectively one must begin with a geological model. Therefore, the science of geology should be used as the basis for lunar exploration. From an astronomical point of view, a lunar terrain heavily impacted with meteors appears the more reasonable; although from a geological standpoint, volcanism seems the more probable mechanism. A surface liberally marked with volcanic features has been advocated by such geologists as Bülow, Dana, Suess, von Wolff, Shaler, Spurr, and Kuno. In this paper, both the impact and volcanic hypotheses are considered in the application of the geo-sciences to manned lunar exploration. However, more emphasis is placed on the volcanic, or more correctly the defluidization, hypothesis to account for lunar surface features.

Asteroid and Comet Impact Speeds upon Mars: Significance for Panspermia and the Supply of Organics

1997 ◽  
Vol 161 ◽  
pp. 197-201 ◽  
Author(s):  
Duncan Steel
Keyword(s):  
Probability Distributions ◽  
Regions Of Interest ◽  
Significant Fraction ◽  
Organic Chemicals ◽  
Impact Speed ◽  
The Mean ◽  
The Impact

AbstractWhilst lithopanspermia depends upon massive impacts occurring at a speed above some limit, the intact delivery of organic chemicals or other volatiles to a planet requires the impact speed to be below some other limit such that a significant fraction of that material escapes destruction. Thus the two opposite ends of the impact speed distributions are the regions of interest in the bioastronomical context, whereas much modelling work on impacts delivers, or makes use of, only the mean speed. Here the probability distributions of impact speeds upon Mars are calculated for (i) the orbital distribution of known asteroids; and (ii) the expected distribution of near-parabolic cometary orbits. It is found that cometary impacts are far more likely to eject rocks from Mars (over 99 percent of the cometary impacts are at speeds above 20 km/sec, but at most 5 percent of the asteroidal impacts); paradoxically, the objects impacting at speeds low enough to make organic/volatile survival possible (the asteroids) are those which are depleted in such species.

Organic Syntheses During the Impact of a Comet with a Gaseous Planet

1997 ◽  
Vol 161 ◽  
pp. 189-195
Author(s):  
Cesare Guaita ◽  
Roberto Crippa ◽  
Federico Manzini
Keyword(s):  
Polymeric Material ◽  
Molecular Form ◽  
Parent Compound ◽  
Blue Filter ◽  
Organic Syntheses ◽  
The Impact

AbstractA large amount of CO has been detected above many SL9/Jupiter impacts. This gas was never detected before the collision. So, in our opinion, CO was released from a parent compound during the collision. We identify this compound as POM (polyoxymethylene), a formaldehyde (HCHO) polymer that, when suddenly heated, reformes monomeric HCHO. At temperatures higher than 1200°K HCHO cannot exist in molecular form and the most probable result of its decomposition is the formation of CO. At lower temperatures, HCHO can react with NH3 and/or HCN to form high UV-absorbing polymeric material. In our opinion, this kind of material has also to be taken in to account to explain the complex evolution of some SL9 impacts that we observed in CCD images taken with a blue filter.

Hydrogen Cyanide Polymers from the Impact of Comet P/Shoemaker-Levy 9 on Jupiter

1997 ◽  
Vol 161 ◽  
pp. 179-187
Author(s):  
Clifford N. Matthews ◽  
Rose A. Pesce-Rodriguez ◽  
Shirley A. Liebman
Keyword(s):  
Amino Acids ◽  
Solar System ◽  
Hydrogen Cyanide ◽  
Nitrogen Heterocycles ◽  
Laboratory Studies ◽  
Heterogeneous Solids ◽  
The Many ◽  
Comet Halley ◽  
The Impact ◽  
By Products

AbstractHydrogen cyanide polymers – heterogeneous solids ranging in color from yellow to orange to brown to black – may be among the organic macromolecules most readily formed within the Solar System. The non-volatile black crust of comet Halley, for example, as well as the extensive orangebrown streaks in the atmosphere of Jupiter, might consist largely of such polymers synthesized from HCN formed by photolysis of methane and ammonia, the color observed depending on the concentration of HCN involved. Laboratory studies of these ubiquitous compounds point to the presence of polyamidine structures synthesized directly from hydrogen cyanide. These would be converted by water to polypeptides which can be further hydrolyzed to α-amino acids. Black polymers and multimers with conjugated ladder structures derived from HCN could also be formed and might well be the source of the many nitrogen heterocycles, adenine included, observed after pyrolysis. The dark brown color arising from the impacts of comet P/Shoemaker-Levy 9 on Jupiter might therefore be mainly caused by the presence of HCN polymers, whether originally present, deposited by the impactor or synthesized directly from HCN. Spectroscopic detection of these predicted macromolecules and their hydrolytic and pyrolytic by-products would strengthen significantly the hypothesis that cyanide polymerization is a preferred pathway for prebiotic and extraterrestrial chemistry.

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