The Impact of Fuel Mass, Injection Pressure, Ambient Temperature, and Swirl Ratio on the Mixture Preparation of a Pilot Injection

A two-tracer laser-induced fluorescence technique is used to quantify the effects of preferential evaporation of multicomponent fuels on the fuel component distribution. The technique is based on the simultaneous detection of the fluorescence of two aromatic tracers with complementary evaporation characteristics matched to different components of a multicomponent fuel. Relative variations in the spatial distribution of tracer distribution as a consequence of preferential evaporation are determined from the ratio of laser-induced fluorescence signals measured within two distinct spectral bands. A thermodynamic model is then used to relate the ratio map with the fuel component map. The accuracy and precision of the method are characterized from determining the laser-induced fluorescence signal ratio within two identical spectral bands. Measurements are performed in a high-pressure high-temperature vessel equipped with an eight-hole injector. The Engine Combustion Network Spray G target conditions are chosen as reference conditions at injection. The only difference with these target conditions is the use of a multicomponent surrogate fuel. Parametric variations around these target conditions are also performed in order to investigate their effect on the preferential evaporation effect. The ambient temperature is varied between 525 and 625 K and the injection pressure is reduced from 200 to 100 bar. The impact of ethanol addition is also studied with two different fuel mixtures in addition to the reference surrogate fuel: E20 and E85 which feature 20% and 85% of pure ethanol within surrogate, respectively. A significant preferential evaporation effect is observed in this condition representative of engine applications and results in a spatial segregation between low- and high-volatility fuel components, respectively, at the tail and tip of the plumes. This effect is enhanced by the addition of ethanol and the decrease in ambient temperature and injection pressure.

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The Impact of Swirl Ratio and Injection Pressure on Fuel-Air Mixing in a Light-Duty Diesel Engine

ASME 2012 Internal Combustion Engine Division Spring Technical Conference ◽

10.1115/ices2012-81234 ◽

2012 ◽

Cited By ~ 6

Author(s):

Dipankar Sahoo ◽

Benjamin R. Petersen ◽

Paul C. Miles

Keyword(s):

Diesel Engine ◽

Heat Release ◽

Mixture Distribution ◽

Injection Pressure ◽

Operating Mode ◽

Swirl Ratio ◽

Rich Mixture ◽

Light Duty ◽

Start Of Injection ◽

The Impact

Toluene fuel-tracer laser-induced fluorescence is employed to quantitatively measure the equivalence ratio distributions in the cylinder of a light-duty diesel engine operating in a low-temperature, high-EGR, and early-injection operating mode. Measurements are made in a non-combusting environment at crank angles capturing the mixture preparation period: from the start-of-injection through the onset of high-temperature heat release. Three horizontal planes are considered: within the clearance volume, the bowl rim region, and the lower bowl. Swirl ratio and injection pressure are varied independently, and the impact of these parameters on the mixture distribution is correlated to the heat release rate and the engine-out emissions. As the swirl ratio or injection pressure is increased, the amount of over-lean mixture in the upper central region of the combustion chamber, in the bowl rim region and above, also increases. Unexpectedly, increased injection pressure results in a greater quantity of over-rich mixture within the squish volume.

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Modeling the Ignitability of a Pilot Injection for a Diesel Primary Reference Fuel: Impact of Injection Pressure, Ambient Temperature and Injected Mass

SAE International Journal of Fuels and Lubricants ◽

10.4271/2014-01-1258 ◽

2014 ◽

Vol 7 (1) ◽

pp. 48-64 ◽

Cited By ~ 10

Author(s):

Federico Perini ◽

Dipankar Sahoo ◽

Paul C. Miles ◽

Rolf D. Reitz

Keyword(s):

Ambient Temperature ◽

Injection Pressure ◽

Pilot Injection ◽

Primary Reference

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Evaluation the effect of the ambient temperature on the liquid petroleum gas transportation pipeline

Chemical Product and Process Modeling ◽

10.1515/cppm-2021-0024 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Ammar Ali Abd ◽

Samah Zaki Naji ◽

Ching Thian Tye ◽

Mohd Roslee Othman

Keyword(s):

Energy Consumption ◽

Greenhouse Gases ◽

Ambient Temperature ◽

Phase Change ◽

Liquid State ◽

Pump Energy ◽

Compressible Liquid ◽

Liquefied Petroleum Gas ◽

Efficient Design ◽

The Impact

Abstract Liquefied petroleum gas (LPG) plays a major role in worldwide energy consumption as a clean source of energy with low greenhouse gases emission. LPG transportation is exhibited through networks of pipelines, maritime, and tracks. LPG transmission using pipeline is environmentally friendly owing to the low greenhouse gases emission and low energy requirements. This work is a comprehensive evaluation of transportation petroleum gas in liquid state and compressible liquid state concerning LPG density, temperature and pressure, flow velocity, and pump energy consumption under the impact of different ambient temperatures. Inevitably, the pipeline surface exchanges heat between LPG and surrounding soil owing to the temperature difference and change in elevation. To prevent phase change, it is important to pay attention for several parameters such as ambient temperature, thermal conductivity of pipeline materials, soil type, and change in elevation for safe, reliable, and economic transportation. Transporting LPG at high pressure requests smaller pipeline size and consumes less energy for pumps due to its higher density. Also, LPG transportation under moderate or low pressure is more likely exposed to phase change, thus more thermal insulation and pressure boosting stations required to maintain the phase envelope. The models developed in this work aim to advance the existing knowledge and serve as a guide for efficient design by underling the importance of the mentioned parameters.

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A novel mouse model of heatstroke accounting for ambient temperature and relative humidity

Journal of Intensive Care ◽

10.1186/s40560-021-00546-8 ◽

2021 ◽

Vol 9 (1) ◽

Author(s):

Kazuyuki Miyamoto ◽

Keisuke Suzuki ◽

Hirokazu Ohtaki ◽

Motoyasu Nakamura ◽

Hiroki Yamaga ◽

...

Keyword(s):

Gene Expression ◽

Body Temperature ◽

Relative Humidity ◽

Ambient Temperature ◽

Core Body Temperature ◽

Heat Exposure ◽

Organ Damage ◽

Core Body ◽

The Impact ◽

Treatment Water

Abstract Background Heatstroke is associated with exposure to high ambient temperature (AT) and relative humidity (RH), and an increased risk of organ damage or death. Previously proposed animal models of heatstroke disregard the impact of RH. Therefore, we aimed to establish and validate an animal model of heatstroke considering RH. To validate our model, we also examined the effect of hydration and investigated gene expression of cotransporter proteins in the intestinal membranes after heat exposure. Methods Mildly dehydrated adult male C57/BL6J mice were subjected to three AT conditions (37 °C, 41 °C, or 43 °C) at RH > 99% and monitored with WetBulb globe temperature (WBGT) for 1 h. The survival rate, body weight, core body temperature, blood parameters, and histologically confirmed tissue damage were evaluated to establish a mouse heatstroke model. Then, the mice received no treatment, water, or oral rehydration solution (ORS) before and after heat exposure; subsequent organ damage was compared using our model. Thereafter, we investigated cotransporter protein gene expressions in the intestinal membranes of mice that received no treatment, water, or ORS. Results The survival rates of mice exposed to ATs of 37 °C, 41 °C, and 43 °C were 100%, 83.3%, and 0%, respectively. From this result, we excluded AT43. Mice in the AT 41 °C group appeared to be more dehydrated than those in the AT 37 °C group. WBGT in the AT 41 °C group was > 44 °C; core body temperature in this group reached 41.3 ± 0.08 °C during heat exposure and decreased to 34.0 ± 0.18 °C, returning to baseline after 8 h which showed a biphasic thermal dysregulation response. The AT 41 °C group presented with greater hepatic, renal, and musculoskeletal damage than did the other groups. The impact of ORS on recovery was greater than that of water or no treatment. The administration of ORS with heat exposure increased cotransporter gene expression in the intestines and reduced heatstroke-related damage. Conclusions We developed a novel mouse heatstroke model that considered AT and RH. We found that ORS administration improved inadequate circulation and reduced tissue injury by increasing cotransporter gene expression in the intestines.

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Detailed Injection Strategy Analysis of a Heavy-Duty Diesel Engine Running on Rape Methyl Ester

Energies ◽

10.3390/en14133717 ◽

2021 ◽

Vol 14 (13) ◽

pp. 3717

Author(s):

Nikita Zuev ◽

Andrey Kozlov ◽

Alexey Terenchenko ◽

Kirill Karpukhin ◽

Ulugbek Azimov

Keyword(s):

Fuel Injection ◽

Combustion Process ◽

Pressure Rise ◽

Base Case ◽

Biodiesel Fuel ◽

Pilot Injection ◽

Post Injection ◽

Heavy Duty ◽

Injection Strategy ◽

Fuel Mass

Using biodiesel fuel in diesel engines for heavy-duty transport is important to meet the stringent emission regulations. Biodiesel is an oxygenated fuel and its physical and chemical properties are close to diesel fuel, yet there is still a need to analyze and tune the fuel injection parameters to optimize the combustion process and emissions. A four-injections strategy was used: two pilots, one main and one post injection. A highly advanced SOI decreases the NOx and the compression work but makes the combustion process less efficient. The pilot injection fuel mass influences the combustion only at injection close to the top dead center during the compression stroke. The post injection has no influence on the compression work, only on the emissions and the indicated work. An optimal injection strategy was found to be: pilot SOI 19.2 CAD BTDC, pilot injection fuel mass 25.4%; main SOI 3.7 CAD BTDC, main injection fuel mass 67.3% mg; post SOI 2 CAD ATDC, post injection fuel mass 7.3% (the injection fuel mass is given as a percentage of the total fuel mass injected). This allows the indicated work near the base case level to be maintained, the pressure rise rate to decrease by 20% and NOx emissions to decrease by 10%, but leads to a 5% increase in PM emissions.

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Silane Functionalized Ethylene/Diene Copolymer Modifiers in Composites of Heterophasic Polypropylene and Microsilica

Polymers and Polymer Composites ◽

10.1177/096739110701500501 ◽

2007 ◽

Vol 15 (5) ◽

pp. 343-355 ◽

Cited By ~ 1

Author(s):

S. Lipponen ◽

P. Pietikäinen ◽

U. Vainio ◽

R. Serimaa ◽

J.V. Seppälä

Keyword(s):

Glass Transition ◽

Transition Temperature ◽

Glass Transition Temperature ◽

Impact Strength ◽

Ambient Temperature ◽

Metallocene Catalyst ◽

The Poor ◽

Rubber Toughened ◽

Rubbery Phase ◽

The Impact

Ethylene/1,7-octadiene copolymer was polymerised with metallocene catalyst and hydrosilylated to form silane functionalised polyethylenes (PE-co-SiX, X=Cl, OEt, Ph). The functionalised species were tested as modifiers in composites of rubber toughened polypropylene (heterophasic PP, hPP) and microsilica filler (μSi). A metallocene-based functionalised PE (PE-co-SiF) produced earlier in our laboratory and three commercial grades of functionalised polyolefins (one PE- and two PP-based) were used as reference modifiers. Major differences were seen in the toughness of the composites both above and below the glass transition temperature (Tg) of PP. In addition to increasing the stiffness, the microsilica filler enhanced the toughness of the heterophasic polypropylene by over 200% at ambient temperature. Below the Tg of PP (at −20 °C), the influence of μSi was the opposite and the impact strength of the hPP/μSi composite was below that of unfilled hPP. With the addition of just 2 wt% of functionalised polyethylene, the poor cold toughness of hPP/μSi composite was improved by nearly 100%. With the same addition, the toughness of the composites at ambient temperature was improved by 50 to 100% compared with the unfilled hPP. This behaviour was explained by significant changes in the fracture mechanism. Addition of functionalised PE increased the concentration of microsilica in the rubbery phase, allowing the crack to enter that phase. The rubbery phase was also able to absorb a large amount of impact energy below the glass transition temperature of PP.

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Impacts of multiple pilot diesel injections on the premixed combustion of ethanol fuel

Proceedings of the Institution of Mechanical Engineers Part D Journal of Automobile Engineering ◽

10.1177/0954407017706858 ◽

2017 ◽

Vol 232 (6) ◽

pp. 738-754 ◽

Cited By ~ 1

Author(s):

Tongyang Gao ◽

Shui Yu ◽

Tie Li ◽

Ming Zheng

Keyword(s):

Direct Injection ◽

Pressure Rise ◽

Pilot Injection ◽

Moderate Pressure ◽

Ethanol Fuel ◽

Injection Process ◽

Rise Rate ◽

Efficient Combustion ◽

Gas Recirculation ◽

The Impact

Engine experiments were carried out to study the impact of multiple pilot injections of a diesel fuel on dual-fuel combustion with a premixed ethanol fuel, using compression ignition. Because of the contrasting volatility and the reactivity characteristics of the two fuels, the appropropriate scheduling of pilot diesel injections in a high-pressure direct-injection process is found to be effective for improving the clean and efficient combustion of ethanol which is premixed with air using a low-pressure port injection. The timing and duration of each of the multiple pilot injections were investigated, in conjunction with the use of exhaust gas recirculation and intake air boosting to accommodate the variations in the engine load. For correct fuel and air management, an early pilot injection of fuel acted effectively as the reactivity improver to the background ethanol, whereas a late pilot injection acted deterministically to initiate combustion. The experimental results further revealed a set of pilot injection strategies which resulted in an increased ethanol ratio, thereby reducing the emission reductions while retaining a moderate pressure rise rate during combustion.

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