Similarity motions of a gas in the case of local supply of mass and energy in a fuel mixture

1980 ◽  
Vol 14 (4) ◽  
pp. 529-535 ◽  
Author(s):  
N. S. Zakharov ◽  
V. P. Korobeinikov
Keyword(s):  
Fuel Mixture ◽  
Local Supply

Effect of Chemical Hythane Composition on Pressure in Combustion Chamber of Engine

2019 ◽  
pp. 36-42
Author(s):  
A. P. Shaikin ◽  
I. R. Galiev
Keyword(s):  
Natural Gas ◽  
Combustion Chamber ◽  
Power Plants ◽  
Engine Speed ◽  
Combustion Engine ◽  
Fuel Mixture ◽  
Maximum Pressure ◽  
Chamber Volume ◽  
Excess Air ◽  
Scientific Papers

The article analyzes the influence of chemical composition of hythane (a mixture of natural gas with hydrogen) on pressure in an engine combustion chamber. A review of the literature has showed the relevance of using hythane in transport energy industry, and also revealed a number of scientific papers devoted to studying the effect of hythane on environmental and traction-dynamic characteristics of the engine. We have studied a single-cylinder spark-ignited internal combustion engine. In the experiments, the varying factors are: engine speed (600 and 900 min-1), excess air ratio and hydrogen concentration in natural gas which are 29, 47 and 58% (volume).The article shows that at idling engine speed maximum pressure in combustion chamber depends on excess air ratio and proportion hydrogen in the air-fuel mixture – the poorer air-fuel mixture and greater addition of hydrogen is, the more intense pressure increases. The positive effect of hydrogen on pressure is explained by the fact that addition of hydrogen contributes to increase in heat of combustion fuel and rate propagation of the flame. As a result, during combustion, more heat is released, and the fuel itself burns in a smaller volume. Thus, the addition of hydrogen can ensure stable combustion of a lean air-fuel mixture without loss of engine power. Moreover, the article shows that, despite the change in engine speed, addition of hydrogen, excess air ratio, type of fuel (natural gas and gasoline), there is a power-law dependence of the maximum pressure in engine cylinder on combustion chamber volume. Processing and analysis of the results of the foreign and domestic researchers have showed that patterns we discovered are applicable to engines of different designs, operating at different speeds and using different hydrocarbon fuels. The results research presented allow us to reduce the time and material costs when creating new power plants using hythane and meeting modern requirements for power, economy and toxicity.

Hasty Pudding Versus Tasty Bread: Regional Variations in Diet and Nutrition during the Industrial Revolution

2012 ◽  
pp. 9-30 ◽  
Author(s):  
Sara Horrell ◽  
Deborah Oxley
Keyword(s):  
Dairy Products ◽  
Industrial Revolution ◽  
Local Economy ◽  
Household Level ◽  
Level Data ◽  
Other Information ◽  
Level Information ◽  
Local Supply ◽  
Key Aspects ◽  
Nutritional Score

Using parish-level information from Sir F.M. Eden's The state of the poor (1797) we can identify typical diets for the counties of England. These diets varied considerably and afforded very different standards of nutrition. We compute a nutritional score for this diet, paying attention to the presence of vitamins, minerals and micronutrients shown to be essential for health and growth in constructing this measure. Other information in the reports allows us to relate county-level nutrition to factors in the local economy. In particular we find nutrition was positively related to the availability of common land in the area and to women's remunerated work if conducted from home. Lack of common land and little local supply of dairy products also pushed households into buying white wheaten bread rather than baking their own wholemeal loaf. Replicating some of this analysis with household-level data confirms these results. Diet also maps onto stature: male convicts to Australia were significantly taller if they originated in a county with a more nutritious diet. This verifies the important impact of nutrition on stature and demonstrates the sensitivity of height as a measure of key aspects of welfare.

Framework

2018 ◽  
Author(s):  
Alan Roe ◽  
Jeffery Round
Keyword(s):  
Supply Chains ◽  
Social Impacts ◽  
Income Growth ◽  
Direct Effects ◽  
Local Supply ◽  
Multiplier Effects ◽  
Economic And Social Impacts

This chapter discusses the channels of impact of an extractives activity on an economy by describing the different routes through which the direct economic and social impacts of these activities might be enhanced. These routes include those that often have the highest political profile, namely spending of government revenues. It also discusses other channels that arguably are far more important, such as the direct effects of corporate spend in local supply chains; the immediate ‘multiplier’ effects of this; the further multipliers that follow from significant income growth; the new downstream activities that may be built on the primary extractive activity; and the externalities that may accrue from the direct boost that a large extractive investment is likely to provide.

Effects of initial temperature on ignition and flame propagation of dual-fuel mixture in mixing layer

2021 ◽  
Vol 225 ◽  
pp. 468-484
Author(s):  
Xiaojun Zhang ◽  
Chengwei Yuan ◽  
Lei Zhou ◽  
Wanhui Zhao ◽  
Zongkuan Liu ◽  
...  
Keyword(s):  
Flame Propagation ◽  
Initial Temperature ◽  
Mixing Layer ◽  
Fuel Mixture ◽  
Dual Fuel

scholarly journals Heating of the fuel mixture due to viscous stress ahead of accelerating flames in deflagration-to-detonation transition

2008 ◽  
Vol 372 (27-28) ◽  
pp. 4850-4857 ◽  
Author(s):  
Damir Valiev ◽  
Vitaly Bychkov ◽  
V'yacheslav Akkerman ◽  
Lars-Erik Eriksson ◽  
Mattias Marklund
Keyword(s):  
Fuel Mixture ◽  
Viscous Stress ◽  
Deflagration To Detonation Transition ◽  
Detonation Transition

The Public Purchase of Grain on Independent Delos

1993 ◽  
Vol 12 (2) ◽  
pp. 300-334 ◽  
Author(s):  
Gary Reger
Keyword(s):  
Local Population ◽  
Aggregate Demand ◽  
Point Of View ◽  
Third Century ◽  
The Public ◽  
Price Structure ◽  
Grain Trade ◽  
Local Supply ◽  
The Impact ◽  
Grain Prices

Earlier work has tended to view Delos as an entrepôt for the larger Hellenistic grain trade, but during the years of independence (314-167 B.C.) the island relied on the import of grain to satisfy local demand, and this was certainly the more important aspect of the trade in grain, at least from the Delians' point of view. This study explores several issues connected with the local supply of grain. From prices for grain reported in inscriptions and estimates of the local population, the aggregate annual demand for grain is estimated, and the price structure of grain derived; the ratio of wheat and barley prices on Delos is found to differ considerably from that known from Athens and Roman Egypt. The shortage of 282 B.C., assumed by earlier scholars from prices recorded for that year, is shown instead to be a period of atypically low prices. The impact of the sailing season on shipments of grain is explored, and an annual rhythm in grain prices and availability linked to the closure of the sea and the agricultural year is revealed. The Delians tried to reduce the impact of these fluctuations by the public purchase of grain on an irregular basis in the late fourth and third century, as attested through public loans; by the last quarter of the third century they had established a regular sitōnia fund to buy grain for resale at reduced prices. Comparison of funds available, grain prices, and the estimated aggregate demand suggest that the Delian sitōnia was able to cover a significant fraction of local demand; this contrasts with evidence from other cities. Some of the implications of these results for our understanding of the Hellenistic economy are briefly explored.

Dual-Location Fuel Injection Effects on Emissions and NO*/OH* Chemiluminescence in a High Intensity Combustor

2016 ◽  
Vol 138 (4) ◽  
Author(s):  
Ahmed O. Said ◽  
Ahmed E. E. Khalil ◽  
Ashwani K. Gupta
Keyword(s):  
Fuel Injection ◽  
Single Injection ◽  
Mixing Time ◽  
Fuel Mixture ◽  
Combustion Noise ◽  
Fuel Distribution ◽  
Mixture Preparation ◽  
Pollutants Emission ◽  
Fuel Mixing ◽  
Colorless Distributed Combustion

Colorless distributed combustion (CDC) has shown to provide ultra-low emissions of NO, CO, unburned hydrocarbons, and soot, with stable combustion without using any flame stabilizer. The benefits of CDC also include uniform thermal field in the entire combustion space and low combustion noise. One of the critical aspects in distributed combustion is fuel mixture preparation prior to mixture ignition. In an effort to improve fuel mixing and distribution, several schemes have been explored that includes premixed, nonpremixed, and partially premixed. In this paper, the effect of dual-location fuel injection is examined as opposed to single fuel injection into the combustor. Fuel distribution between different injection points was varied with the focus on reaction distribution and pollutants emission. The investigations were performed at different equivalence ratios (0.6–0.8), and the fuel distribution in each case was varied while maintaining constant overall thermal load. The results obtained with multi-injection of fuel using a model combustor showed lower emissions as compared to single injection of fuel using methane as the fuel under favorable fuel distribution condition. The NO emission from double injection as compared to single injection showed a reduction of 28%, 24%, and 13% at equivalence ratio of 0.6, 0.7, and 0.8, respectively. This is attributed to enhanced mixture preparation prior to the mixture ignition. OH* chemiluminescence intensity distribution within the combustor showed that under favorable fuel injection condition, the reaction zone shifted downstream, allowing for longer fuel mixing time prior to ignition. This longer mixing time resulted in better mixture preparation and lower emissions. The OH* chemiluminescence signals also revealed enhanced OH* distribution with fuel introduced through two injectors.

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