Effect of Swirl and Injection Pressure on Performance and Emissions of JP-8 Fueled High Speed Single Cylinder Diesel Engine

JP-8 is being closely watched as a suitable fuel for the “One fuel policy” by US Army. Some of the main targets of Army in the battle are the fuel economy and smoke/soot emissions. Soot emissions can be reduced in two ways, by increasing the injection pressure or by increasing swirl. An investigation was conducted to find out the more effective way to reduce soot emissions and to evaluate the influence of the swirl motion on JP-8 fuel combustion, performance and emissions in a single cylinder diesel engine. Increasing swirl increased heat losses and produced lower temperatures during injection process. Increasing swirl improved the premixed combustion fraction and produced higher peak temperatures and in turn increased NOx emissions. Increasing swirl also increased the nano-particle emissions.

Effect of Biodiesel, Jet Propellant (JP-8) and Ultra Low Sulfur Diesel Fuel on Auto-Ignition, Combustion, Performance and Emissions in a Single Cylinder Diesel Engine

Concern about the depletion of petroleum reserves, rising prices of conventional fuels, security of supply and global warming have driven research toward the development of renewable fuels for use in diesel engines. These fuels have different physical and chemical properties that affect the diesel combustion process. This paper compares between the autoignition, combustion, performance and emissions of soy-bean derived biodiesel, Jet propellant (JP-8) and ultra low sulfur diesel (ULSD) in a high speed single-cylinder research diesel engine equipped with a common rail injection system. Tests were conducted at steady state conditions at different injection pressures ranging from 600 bar to 1200 bar. The ‘rate of heat release’ traces are analyzed to determine the effect of fuel properties on the ignition delay, premixed combustion fraction and mixing and diffusion controlled combustion fractions. Biodiesel produced the largest diffusion controlled combustion fraction at all injection pressures compared to ULSD and JP-8. At 600 bar injection pressure, the diffusion controlled combustion fraction for biodiesel was 53% whereas both JP-8 and ULSD produced 39%. In addition, the effect of fuel properties on engine performance, fuel economy, and engine-out emissions is determined. On an average JP-8 produced 3% higher thermal efficiency than ULSD. Special attention is given to the oxides of nitrogen (NOx) emissions and particulate matter characteristics. On an average biodiesel produced 37% less NOx emissions compared to ULSD and JP-8.

Effect of Biodiesel, JP-8 and Ultra Low Sulfur Diesel Fuel on Autoignition, Combustion, Performance and Emissions in a Single Cylinder Diesel Engine

Concern about the depletion of petroleum reserves, rising prices of conventional fuels, security of supply and global warming have driven research toward the development of renewable fuels for use in diesel engines. These fuels have different physical and chemical properties that affect the diesel combustion process. This paper compares between the autoignition, combustion, performance and emissions of soybean derived biodiesel, JP-8 and ultra low sulfur diesel (ULSD) in a high speed single-cylinder research diesel engine equipped with a common rail injection system. Tests were conducted at steady state conditions at different injection pressures ranging from 600 bar to 1200 bar. The ‘rate of heat release’ traces are analyzed to determine the effect of fuel properties on the ignition delay, premixed combustion fraction and mixing and diffusion controlled combustion fractions. Biodiesel produced the largest diffusion controlled combustion fraction at all injection pressures compared to ULSD and JP-8. At 600 bar injection pressure, the diffusion controlled combustion fraction for biodiesel was 53% whereas both JP-8 and ULSD produced 39%. In addition, the effect of fuel properties on engine performance, fuel economy, and engine-out emissions is determined. On an average JP-8 produced 3% higher thermal efficiency than ULSD. Special attention is given to the NOx emissions and particulate matter characteristics. On an average biodiesel produced 37% less NOx emissions compared to ULSD and JP-8.

New 14C Ages on Cellulose from Diprotodon Gut Contents: Explorations in Oxidation Chemistry and Combustion

We report radiocarbon ages on cellulose isolated from the gut contents of a Diprotodon found at Lake Callabonna, South Australia. The maximum age obtained corresponds to a minimum age of >53,400 BP for this extinct giant marsupial. This is older than, and hence consistent with, the generally accepted Australian megafauna extinction window. We argue that dichromate and other strong oxidants are less selective than chlorite for lignin destruction in wood, and our results suggest that ages approaching laboratory background can be obtained using a repeated pretreatment sequence of chlorite-alkali-acid and measurement of the sometimes discarded 330°C combustion fraction.

Tobacco as Potential Food Source and Smoke Material

Fraction I protein is the most abundant protein in tobacco and accounts for 50 % of its soluble protein. It is composed entirely of amino acids. Its specific nutritional value is comparable with milk and surpasses that of soybeans. During tobacco combustion, Fraction I protein may contribute to the formation of HCN and other undesirable nitrogenous constituents in smoke. It can be removed from harvested leaf tobacco through homogenized leaf curing (HLC) process to improve leaf quality and usability. Considering the total world tobacco production as a whole, Fraction I protein and other soluble proteins so recovered may provide enough food for millions of people. In addition, there will also be a better smoking product