Cylinderpressure is one ofthe main parameters ofdiesel engine combustion affecting several changes in exhaust gas emission composition and amount as well as engine useful power, specifically when alternative fuels are used. One among other alternative fuels for diesel engine is hydrogen that can be used as fumigated reagent with air prior to intake to engine in order to substitute the main fossil diesel. In this study, experimental investigation was accomplished using a single cylinderdiesel engine for agriculture running on different ratios ofhydrogen-to-diesel. Cylinderpressure traces corresponding to the crank angle positions were indicated and analyzed for maximum cylinderpressure and their coefficient of variation. The regression analysis is used to find the correlations between hydrogen percentage and the maximum cylinderpressure as well as its coefficient of variation. When higher hydrogen percentages were added, thecombustion shifted toward later crank angles with the maximum cylinderpressure decreased and eminent effects at higher load and speed. The plots ofhydrogen percentage against the coefficient of variation ofthe maximum cylinderpressure (COV Pmax ) show the increase in variation of maximum cylinder
Figure 11 indicates the concentrations of NOx emissions for the engine operated with single mode and dual-fuelcombustion modes. In Figure 11, with increase in engine load, the NOx concentrations of all test conditions are increased steeply. However, the NOx emissions emitted under thedual-fuel operation for both pilot fuels were lower compared to the single mode at all test ranges, In the case ofthe single mode, biodiesel combustion produced higher concentrations of NOx emissions at all engine loads, compared to dieselfuel. This is due to oxygen content, faster injection and early ignition characteristics of biodiesel. This resulted in a slightly higher maximum combustionpressure and temperature, which enhance the formation of NOx emissions. Again in case ofdual-fuel operations, the concentrations of NOx emissions were significantly lower at all engine loads, on average about 60% below the levels measured in single mode combustion. This is because of low combustion rate ofthe gaseous fuel in the presence of CO 2 in biogas. The CO 2 of biogas dilutes the oxygen concentration ofthe intake fluid. It has
from the intake port through the open intake valve into thecombustion chamber, where it causes effects of turbulence and charge stratification particularly at engine part load operations. The system is able to diminish the cyclic variations and to expand the limit of lean operation ofthe engine. The flexibility of gas pulse timing offers the potential advantage of lower emissions and fuel consumption. With three types of port injectors available on the market, Czerwinski  were compared for stationary and transient engine operation. There are several advantages of port injection, e.g., better possibility to equalize the air-fuel ratio ofthe cylinders, optimization ofthe gas injection timing and ofthe gas pressure for different operating conditions. The port injection has an injector for each cylinder, so the injectors can be placed in close proximity to the cylinder's intake port. It also enables fuel to be delivered precisely as required to each individual cylinder (called sequential) and enables more sophisticated technologies such as skip-firing to be used. Skip-firing is when only some ofthe cylinders are operating (the other cylinders are being skipped). This enables even more efficient use ofthefuel at low loads, further lowering fuel consumption and unburned hydrocarbon.
A relatively complete procedure for high cycle fatigue life assess- ment ofthe engine components is outlined in the present paper. The piston is examined as a typical component ofthe engine. In this regard, combustion process and transient heat transfer simu- lations, determination ofthe instantaneous variationsofthe pres- sure and temperature in thecombustion chamber, kinematic and dynamic analyses ofthe moving parts ofthe engine, thermoelastic stress analyses, and fatigue life analyses are accomplished. Results ofthe simulation are compared with the test data to verify the results. The heat transfer results are validated by the experi- mental results measured by the Templugs. The nonlinear mul- tipoint contact constraints are modeled accurately. Results ofthe more accurate available fatigue criteria are compared with those of a fatigue criterion recently proposed by the first author. These results are also evaluated by comparing them with the experi- mental durability tests. The presented procedure may be used, e.g., to decide whether it is suitable to convert a gasoline-based engine to a bi-fuel one. Results ofthe various thermomechanical fatigue analyses performed reveal that the piston life decreases considerably when natural gas is used instead of gasoline.
This work intends to contribute to the development of polymer coatings by utilizing the thermal spray of recycled PET for the im- provement ofthe tribological behavior of carbon steel piping. Here, we describe a study ofthe influences of thermal spraying parameters on the tribological properties of polymeric coatings. Measurement of wear resistance, friction, and Knoop microhardness of these coat- ings are presented. The results were analyzed using the statistical technique design of experiments (DOE) 11 . High-wear resistance
Unlike gasoline or diesel engines, the CAE technology does not use any form of internal combustion. Compressed air (or other gases or combination of gases) is used as energy carrier and storage medium. The air is stored at pressureof around 200bar in compressed air storage cylinders. For energy carrying purpose, thepressureofthe compressed air is reduced to around 10 bar or less using pressure regulator connected in front ofcylinder valve. The air with reduced pressure is carried by poly-Teflon hose. The hose is then connected to the solenoid valve using barbed fitting. The air inlet timing and duration is controlled by the Solenoid valve. A small magnet is attached on the flywheel and a sensor is fitted very close the flywheel. After each revolution ofthe flywheel, the sensor gets activated by the magnetic field ofthe magnet passing nearby and sends signal to solenoid valve. The air is fed through an air injector to the engine and flows into which air expands. The air pushing down on the piston moves the crankshaft, which gives the vehicle power. The flywheel stores some energy to provide it back during the upstroke.
To investigate a possible change of phase composition upon hydrogenation, samples were quenched after 20 minutes and 20 hours under H 2 pressure. “Quenching” was done by closing the sample valve to thehydrogen gas source, retracting the heating unit from the sample holder area and cooling the sample holder down to room temperature in a few seconds using a cold water bath. As MgH 2 and Mg 2 FeH 6 are both highly stable hydrides, the change of phase composition and hydrogen density are minimal upon quenching. Thus, the X-ray powder diffraction patterns of quenched samples truly relect the crystal structure during the reaction ofhydrogen absorption. Figure 4 shows the X-ray powder diffraction patterns ofthe 2Mg-Fe samples quenched after 20 minutes (Figure 4a) and 20 hours (Figure 4b) at 350 °C under 20 and 30 bar of H 2 . By comparing Figures 4a, b, it is clear that even if thehydrogen capacity increased only slightly between 20 minutes and 20 hours the phase composition drastically changed. In Figure 4a, β-MgH 2 and α-Fe are the main phases in the sample hydrogenated for 20 minutes under 20 bar. Mg 2 FeH 6 and Mg diffraction peaks are barely seen
The use of microreactors for in-situ and on- demand chemical processing is gaining increasing importance in the chemical industry. Microreactors have characteristic properties, like a high surface to volume ratio, the use of small amounts of chemicals, high heat and mass transfer rates, and short residence times that make these devices a research topic of high interest. Microreactors have been proposed for various applications, such as intrinsic kinetic studies, catalyst screening, fine-chemical synthesis, and in launching fuel cells systems for portable power generation (Hu et al., 2003; Löwe and Ehrfeld, 1999; Wörz et al., 2001). The microreformer fuel cell combination has the advantage of avoiding the tedious charging cycles needed by conventional rechargeable lithium-ion batteries. Also, the energy storage density per unit weight of this system is higher than that of batteries (Palo et al., 2002; Pattekar et al., 2001; Terazaki et al., 2005). Thus, less frequent recharging in terms of refilling with ethanol fuel is necessary. Membrane microreactors are an important class of microreactors that combine reaction and separation in one single device. Thus, for example, a thin palladium membrane can be included which separates hydrogen from the reformate gas mixture (Alfadhel and Kothare, 2005; Assaf et al., 1998; Karnik et al., 2003). Assaf et al. (1998) modeled the methane steam reforming in an isothermal membrane reactor and concluded that the membrane reactor, besides providing purified hydrogen still presents a higher methane conversion yield than the conventional fixed-bed reactor. This work presents a two-dimensional mathematical model of an isothermal membrane microreactor operating under steady-state conditions for use as a source of pure hydrogen for a PEM fuel cell from ethanol steam reforming catalyzed by Ni/Al 2 O 3 . The
In the present studies physiological aspect ofthe blood flow has been modeled with a view to estimate the physiological flow parameters such as pressure, against adverse conditions. The study is basically aims at as an advisory and precautionary mode. Efforts have been made to compare the results with practical situations available in the literature with respect to myocardial infarction [heart attack]. Blood flow modeling has paved the way for understanding the intricacy ofthe fluid flow pattern in the human body[1,2].The importance of blood flow in Cardiovascular system has been highlighted by Young. Later the models have been refined by accounting it for pulsatile aspect  and the effects of blood cells [5-6] by using micro-continuum theories [7-9].Effects of body acceleration and magnetism have also been studied on the blood flows [10-12]. In the present model, blood is assumed to be represented by a couple stress fluids  and the model has been developed for the straight tube [Figure1].
Spark plug location on cylinder head of a spark ignition engine plays an important role on combustion characteristics. In this paper an attempt has been made to simulate the effect of eccentricity of spark plug on various combustion parameters such as the maximum temperature ofthe burned and unburned gas, maximum cylinderpressure and normalized flame front area and normalized flame front volume for different values of clearance height, spark advance and crank angle with the help of a two zone combustion model. The simulated results have been compared for a given value of eccentricity with Blizard and Keck  turbulent entrainment model and it shows reasonably good agreement.
Abstract –The reversible fuel cell can be used to produce hydrogen. Thehydrogen is further the chemical energy source to produce electrical energy using thefuel cell. The ambient temperature will influence the parameters ofthehydrogenfuel cell.
As the multinomial model is non-linear, the marginal effect ofthe treatment in a DID model is not the marginal impact ofthe interaction between time and treatment, but the difference ofthe cross-differences, as described by Puhani (2012). The results of Table 7 (in terms of marginal effects) show that the BVJ has a significant effect on the probability studying and working at the same time, but not on the other outcome variables. The estimated marginal effects mean that the probability of a youngster studying and working increases by 4.2 percentage points with the BVJ, compared with a baseline of 30% in the control group in 2006. The estimated coefficients for the categories ‘studying only’ and ‘working only’ were negative but not statistically significant. It seems, therefore, that treated adolescents do not quit their jobs to study because ofthe program, but do both activities at the same time. This raises questions about the long run impacts ofthe program, since the quality ofthe night classes is notoriously low in Brazil.
Putaud, J.-P., Raes, F., Van Dingenen, R., Bruggemann, E., Facchini, M. C., Decesari, S., Fuzzi, S., Gehrig, R., Huglin, C., Laj, P., Lorbeer, G., Maenhaut, W., Mihalopoulos, N., Muller, K., Querol, X., Rodriguez, S., Schneider, J., Spindler, G., Brink, H. T., Torseth, K., and Wiedensohler, A.: A European aerosol phenomenology – 2: chemical characteristics of particulate matter at kerbside, urban, rural and background sites in Europe, Atmos. Environ.,
tion.2) it is also found that intake valve lifts with 60 o manifold inclination, maximum turbulence ki- netic energy is highest compared to all other mani- fold inclination. Benny Paul et.al (2010) studied on the effect of helical, spiral, and helical-spiral com- bustion manifold configuration on air motion and turbulence inside thecylinderof direct injection diesel engine. The flow characteristics of these en- gine manifolds are examined under transient condi- tions using CFD code STAR-CD. After the analysis of different manifolds Benny et.al concluded that; 1) swirl ratio inside thecylinder and turbulence kinetic energy is higher for spiral manifold. B) Volumetric efficiency for spiral- helical combined manifold is 105 higher than that of spiral manifold. Baby X et al., have carried out an experimental investigation on in-cylinder motion, during the intake and com- pression strokes of a multi valve engine. Experi- ments were conducted on a single cylinder four valve research engine. The engine was attached with several optical accesses on cylinder liner and cy- linder head. Effects of different piston bowl shapes on turbulence, flow variations and tumble distortion were analyzed. Kuleshov et al., has developed a model that deals with thediesel sprays and combus- tion. Submodels that are capable to predict the emissions like NO and soot have been implemented in the model. The model was used to handle the parameters like injection strategies, injection dura- tion, droplet size and the bowl shape. Heywood has stated that in medium and small DI engines swirl is used to attain adequate fuel-air mixing rates. Air swirl is generated by adopting suitable changes in the design of inlet port. Friction at thecylinder wall surfaces and the turbulent dissipation ofthe fluid tries to reduce the angular momentum ofthe air entering during induction and the same is continued while the compression process is in progress. Swirl velocity can be increases by adopting suitable changes in thecombustion chamber design.
dois óleos crus utilizando TG e DSC, em atmosferas de nitrogênio e ar. Quando o óleo foi aquecido em atmosfera de nitrogênio, observa- ram-se duas regiões de perda de massa, a primeira referente à desti- lação e a segunda envolvendo degradação e craqueamento térmico. Nos ensaios envolvendo atmosfera oxidante (ar), três diferentes re- giões foram identificadas para ambos os óleos, oxidação à baixa temperatura (LTO – “low temperature oxidation”), depósito de com- bustível (FD – “fuel deposit”) e oxidação à alta temperatura (HTO – “high temperature oxidation”). Para a região de HTO, os estudos cinéticos indicaram valores de energia de ativação de 128,3 e 142,3 kJ mol -1 para os dois óleos avaliados. Observaram também que à
O.Badr, N.Alsayed and M. Manaf  Presents the experimental results of a parametric study on lean operational limits of Ricardo E6 Engine using propane and LPG as a fuel. The result had shown that the spark timing have a significant influence on engine lean limit, the research has taken out the results for only first misfire criteria for two speeds only. They had not measured the exhaust emissions and certain other parameter. Tolga Topgul, Huseyin Serdar Yucesu Carried out the performance and exhaust emission investigation on Hydra single cylinder, four stroke S.I engine using unleaded gasoline (E0) and unleaded gasoline ethanol blends (E10, E20 E40 and E60). By varying the compression ratio (8:1, 9:1 and 10:1) and ignition timing at a constant speed of 2000 rpm at wide open throttle (WOT). The experimental results showed that blending slightly increased the brake torque and decreased carbon monoxide (CO) and hydrocarbon (HC) emissions.
Karanja based bio-diesel is a non-edible, biodegradable fuel suitable for diesel engines. Karanja biodiesel has been prepared by transesterification method. Biodiesel-diesel blends have been prepared on volume basis. Physical properties of Karanja biodiesel, diesel and its blends have been determined. An experimental investigation has been carried out to analyze combustion characteristics of a single cylinder, VCR diesel engine fuelled with Karanja biodiesel and its blends (10%, 20%, 30%, 50% and 75%) with neat diesel. A series of engine tests, with CR 16.5, 17.5 and 18.5 have been conducted using each ofthe above blends for comparative evaluation. Combustion parameters such as ignition delay, peak pressure development, heat release rate analysis of engine have been studied. The results ofthe experiment in each case have been compared with baseline data of neat diesel. Ignition delays of bio-diesel blends are lower than that ofdiesel; peak pressure takes place definitely after TDC for safe and efficient operation. Comparable rate ofpressure rise obtained is indicative of stable and noise free operation of CI engines with karanja biodiesel blends. B10 is suitable alternative fuel for diesel at slightly higher CR can be used without any engine modifications.
There were interventions in the engine so we could establish the configuration factor ofthe air and fuel supply system; initially, the tractor’s engine was assessed in its original manufacturing configuration (C1: Aspirated). Later on, with the help of a specialized technician, the injection pump was regulated in a test bench, where theDiesel flow or load of this device went from 67ml at 800rpm ofthe injection pump to 74ml, that is, there was an increase of 10% of injected Diesel, and that determined the second configuration (C2: Aspirated + Service). To evaluate the effects ofthe turbocharger in the engine performance, it was necessary to install a kit to supercharge the air made by Master Power, model APL 240, that has an air intake pressureof 1.0bar, and it was installed after the service at the injection pump (C3: Turbocharged + Service). After the turbocharger was installed, for the last configuration evaluated, again the original flow ofthe injection pump was used (C4: Turbocharged).
During the cleaning of syngas, any particulate such as mercury, sulphur, trace contaminants and foreign matter are removed. Then, the syngas reacts with steam by a process called water gas shift reaction to produce more hydrogen and carbon dioxide as ﬁnal product as in Fig. 16. Thehydrogen then can be used as a vehicle fuel or to generate electricity for other purposes such as power plant and industry. Meanwhile, as carbon dioxide has also been produced at the end, a technology is needed to decrease or at least sustain the amount of carbon dioxide emissions in the atmosphere. Nowadays, carbon dioxide emissions can be reduced near to zero when applying carbon capture storage and seques- trations technologies [82,83]. By increasing the efﬁciency of operation in the gasiﬁcation process, the pollutants can also be reduced signiﬁcantly.