Changes In Engine Design Research Articles

Compression ignition of Hydrogen (H2) in a direct injection diesel engine Modified to operate as a Low Heat Rejection

Global pollution levels in many applications will now be at danger because of the growing need for fuel. CR hydrogen is an alternative to diesel fuel and a possible supply of unspent fuel in India. Using hydrogen as a sole fuel in a direct-injection diesel engine has been tested for its practicality. One-cylinder diesel engine with air cooling was adapted to operate as a low-heat-rejection engine. To protect the engine's combustion chamber, partially stabilized zirconia ceramic components were employed. A single-cylinder compression ratio (CR) engine with varied CR Hydrogen fuels will be studied to determine the optimal performance and emission characteristics. There was a comparison of diesel fuel performance measures such as specific fuel consumption (SFC), brake thermal efficiency (BTE), and emissions of HC, CO, Smoke, and NOx. A compression ratio of 17.5 for hydrogen fuel demonstrates higher performance and reduced emissions, which is quite similar to neat diesel fuel in terms of performance and emissions levels. Different compression ratios (15.5, 16.5, and 17.5) were tested in order to determine the optimal combination for running the engine on hydrogen mixes. Furthermore, the increase in compression ratio raises the BTE, reduces the SFC, and lowers emissions without any engine design changes

How can ports act to reduce underwater noise from shipping? Identifying effective management frameworks

This paper aims to find mechanisms to align commercial interests with underwater noise reductions from commercial shipping. Through a survey and a series of interviews with representative stakeholders, we find that while acknowledging the wide variations in ports' specificities, port actions could support the reduction in underwater noise emissions from commercial shipping through changes in hull, propeller and engine design, and through operational measures associated with reduced speed, change of route and travel in convoy. Though the impact of underwater noise emissions on marine fauna is increasingly shown to be serious and wide-spread, there is uncertainty in the mechanisms, the contexts, and the levels which should lead to action, requiring precautionary management. Vessels owners are already dealing with significant investment and operating costs to comply with fuel, ballast water, NOx and CO2 requirements. To be successful, underwater noise programs should align with these factors.Based on a multiple criteria decision making (MCDM) approach, we find a set of compromise solutions for a wide range of stakeholders. Ports could propose actions such as discounted port fees and reduced ship waiting times at ports, both depending on underwater noise performance. Cooperation between ports to scale up actions through environmental indexes and classification societies' notations, and integration with other ports' actions could help support this. However, few vessels know their underwater noise baseline as there are very few hydrophone stations, and measurement methodologies are not standardized. Costs increase and availability decreases dramatically if the vessel buyer wants to improve the noise profile. Local demands regarding airborne noise close to airports boosted global pressure on the aviation industry to adopt existing quieting technology. This experience of the aviation noise control could inform the underwater noise process.

Impact of Alumina Nanoadditives on Operation and Emission Attributes of Diesel Engine

This paper collectively report work of many researchers on engine operation and emissions of diesel engine with alumina nanoadditive in diesel blends. Fuel blending is a very common and popular practice as compared to making changes in engine design or treating the exhaust gases for hazardous emissions. Alumina nanoadditive related findings are encapsulated here to review the pros and cons of various alternative fuels for better performance and reduced harmful emissions. Many recent researches are now focussed on nanoadditive over microadditives for their high specific surface area, much better combustion characteristics than micron sized additives and shorter ignition delays. Easy dispersion and suspension in liquid fuels can be obtained by Nanoparticles. This review focus on the effect of alumina nanoadditives on the fuel efficiency, brake thermal efficiency, emissions and a summary of the observation from literature is presented here.

OZNACZENIE LEPKOŚCI KINEMATYCZNEJ I GĘSTOŚCI MIESZANINY OLEJU NAPĘDOWEGO Z ETANOLEM I DODATKIEM DODECANOLU

The most popular group of alternative fuels is that derived from renewable sources. This group of fuels includes: vegetable oils and their derivatives (for example, esters of higher carboxylic acids) alcohols (for example, ethanol and methanol) ethers (for example, methyl tert-butyl ether, ethyl tert-butyl ether) liquid biomass processing products ( synthetic fuel). Among this group, the most interesting are alcohols, especially ethanol. This is due to the fact that ethanol has better physicochemical properties than methanol. It can be produced from renewable sources and the manufacturing process is not complicated. Drinking alcohol also reduces emissions of carbon dioxide (CO2) and toxic compounds such as particulate matter and nitrogen oxides (NOx) from diesel engines. By using alternative fuels, costly engine design changes can be avoided and only regulatory changes can be made. The miscibility of ethanol with diesel is influenced by water content and temperature. At a temperature of about 10 ° C, the mixture stratifies. One additive that can be used as a stabilizer for an ethanol-diesel mixture is dodecanol (C12H26). It is obtained by reduction of methyl esters. Dodecanol is solid at a temperature of 24 ° C, insoluble in water and mixes well with diesel fuel and ethyl alcohol. In order for this type of fuel to be used to power diesel engines, it is necessary to know their physicochemical properties, since they have a significant impact on the correct operation of the internal combustion engine, operational parameters and the purity of exhaust gases into the environment. The addition of ethanol to diesel fuel affects key properties such as kinematic viscosity and density. Viscosity affects the atomization and atomization characteristics of the combustion chamber. According to Soter, a lower viscosity value leads to smaller droplet diameters, thus increasing the surface area of the droplets significantly affects the evaporation time of the droplets. Taking into account the processes occurring in the injection systems, the choice of fuel with the optimal viscosity should be a compromise option. On the one hand, the increase in viscosity is favorable due to the efficiency and pressure in the high-pressure pumps and the lubrication conditions of the moving interacting elements of the injection system, but on the other hand, it leads to an increase in energy for pumping fuel into the supply system. On the other hand, an increase in density leads to an increase in particulate emissions. Low density is associated with lower heating value. This will affect the degradation of power and torque. In such a case, in order to reduce the difference, the fuel dose should be increased, the fuel consumption will be increased and the beneficial effect of low fuel density on the reduction of particulate matter emissions will be eliminated. The article presents the results of the study of the issue substantiated the need to measure the kinematic viscosity and density of mixtures of diesel fuel with ethanol and dodecanol. The results of the viscosity measurements can be used to determine the injection parameters and the macrostructure of the atomized fuel flow. KEY WORDS: DIESEL FUEL, ALTERNATIVE FUEL, ETHYL ALCOHOL, DODECANOL, KINETIC VISCOSITY

Particle emissions of two unblended alternative jet fuels in a full scale jet engine

The emission of soot particles from aircraft jet engines is relevant due to their impact on contrail formation and local air quality in airport areas. The reduction of particle emission may be achieved by changes in jet engine design. This, however, will only affect new aircraft. Previous studies have shown that the use of alternative jet fuels feature a co-beneficial reduction of soot emission beside an improved carbon footprint. In the present study, a CFM56-5C4 engine was operated on a test rig with three different fuel types: one reference kerosene, a catalytic hydrothermolysis jet fuel (ReadiJet) and an unblended alcohol-to-jet (ATJ) fuel. Due to the absence of aromatics in the ATJ fuel, ASTM jet fuel requirements are not met, but the use of this fuel led to a reduction of 70% in particle mass compared to the reference fuel. The ReadiJet fuel has higher aromatic content, lower fuel hydrogen content and, thus, an increase in particle emission was observed. For the present engine, the highest soot reductions were observed at lower power settings. In accordance to previous studies, the soot emission showed a good correlation to the hydrogen content of the fuels and the emission reduction matches the estimations of the imFOX model. In order to compare test rig studies to field studies, transient processes must be considered because they govern take-off conditions. Four experiments with different transient thrust patterns were performed on the test rig with regular Jet A-1. If the thrust changes were not very rapid (e.g. 5 s to ~90% thrust) the results could be reproduced with a set of pseudo-stationary processes to a sufficient extend. This emphasizes the relevance of test-rig studies for real in-field measurements and local air quality studies.

Automotive Waste Heat Recovery after Engine Shutoff in Parking Lots

<div class="section abstract"><span class="label">1</span><div class="htmlview paragraph">The efficiency of internal combustion engines remains a research challenge given the mechanical friction and thermodynamic losses. Although incremental engine design changes continue to emerge, the harvesting of waste heat represents an immediate opportunity to address improved energy utilization. An external mobile thermal recovery system for gasoline and diesel engines is proposed for use in parking lots based on phase change material cartridges. Heat is extracted via a retrofitted conduction plate beneath the engine block after engine shutoff. An autonomous robot attaches the cartridge to the plate and transfers the heat from the block to the Phase Change Material (PCM) and returns later to retrieve the packet. These reusable cartridges are then driven to a Heat Extraction and Recycling Tower (HEART) facility where a heat exchanger harvests the thermal energy stored in the cartridges. A series of mathematical models are created to estimate the recoverable heat from a standard parking lot configuration. A representative case study that considered 500 cars with periodic traffic flow over a period of 16 hours can heat approximately 25 kiloliters of potable water from 15°C to 50°C. Future development will involve the creation of strategies to extract heat during engine idling at traffic stops and drive through lanes.</div></div>

Modeling and Analysis of Tier 4 Locomotives Operating in a High-Altitude Tunnel

Tunnels represent one of the most severe operating conditions for diesel engines in diesel-electric locomotive applications, specifically for nonventilated tunnels located at high elevation. High ambient air temperatures are observed in these tunnels due to heat rejected from the locomotive engines through the exhaust and engine cooling and lubrication systems. Engine protection algorithms cause the maximum allowable engine horsepower to be reduced due to these conditions leading to a reduction in train speed and occasionally train stall. A first law based model was developed to simulate the performance of a train pulled by GE diesel-electric locomotives equipped with medium speed diesel engines in a high altitude and nonventilated tunnel. The model was compared against and calibrated to actual tunnel operation data of EPA Tier 2 compliant locomotives. The model was then used to study the impact of engine design changes required for EPA Tier 4 compliant locomotives, specifically the introduction of exhaust gas recirculation (EGR), on engine, locomotive, and train performance in the tunnel. Simulations were completed to evaluate engine control strategies targeting same or better train performance than the EPA Tier 2 compliant locomotive baseline case. Simulation results show that the introduction of EGR reduces train performance in the tunnel by increasing the required reduction in engine horsepower, but is slightly offset by improved performance from other engine design changes. The targeted engine and train performance could be obtained by disabling EGR during tunnel operation.

3D Simulation Methodology for n-Butanol Combustion in an optical accessible research GDI Engine

The strict political regulations in terms of engine tailpipe emissions and reduction of fossil fuel dependency are pushing forward the study of alternative fuels; these fuels must be suitable for currently available engines, in order to allow quick and inexpensive replacement. The alternative fuel chosen for this analysis is n-Butanol; being its key physico-chemical properties similar to those of commercial Gasoline, it does not require relevant changes in engine design and operation and therefore it is suitable for currently produced units. The paper describes the modeling and characterization of spark-ignited combustion of n-Butanol in comparison with that of conventional Gasoline. The comparison is made by means of 3D CFD simulations and experimental tests, carried out on a single-cylinder optically accessible engine characterized by a flat and transparent piston. The engine is equipped with direct injection and makes use of a current production engine head. The operating conditions used in the experiments are reproduced in the CFD simulations, in order to validate the CFD model and to provide additional insight to the experimental observations. The numerical simulation outcomes replicate with a good accuracy the experimental test results and they help to better understand the behavior of the alternative fuel during the combustion process. The adopted modelling methodology can therefore be used for further investigations such as exploration of different engine operations through virtual DOE of both operating and functional parameter variations.

Biofuels, vehicle emissions, and urban air quality.

Increased biofuel content in automotive fuels impacts vehicle tailpipe emissions via two mechanisms: fuel chemistry and engine calibration. Fuel chemistry effects are generally well recognized, while engine calibration effects are not. It is important that investigations of the impact of biofuels on vehicle emissions consider the impact of engine calibration effects and are conducted using vehicles designed to operate using such fuels. We report the results of emission measurements from a Ford F-350 fueled with either fossil diesel or a biodiesel surrogate (butyl nonanoate) and demonstrate the critical influence of engine calibration on NOx emissions. Using the production calibration the emissions of NOx were higher with the biodiesel fuel. Using an adjusted calibration (maintaining equivalent exhaust oxygen concentration to that of the fossil diesel at the same conditions by adjusting injected fuel quantities) the emissions of NOx were unchanged, or lower, with biodiesel fuel. For ethanol, a review of the literature data addressing the impact of ethanol blend levels (E0-E85) on emissions from gasoline light-duty vehicles in the U.S. is presented. The available data suggest that emissions of NOx, non-methane hydrocarbons, particulate matter (PM), and mobile source air toxics (compounds known, or suspected, to cause serious health impacts) from modern gasoline and diesel vehicles are not adversely affected by increased biofuel content over the range for which the vehicles are designed to operate. Future increases in biofuel content when accomplished in concert with changes in engine design and calibration for new vehicles should not result in problematic increases in emissions impacting urban air quality and may in fact facilitate future required emissions reductions. A systems perspective (fuel and vehicle) is needed to fully understand, and optimize, the benefits of biofuels when blended into gasoline and diesel.

The history, genotoxicity, and carcinogenicity of carbon-based fuels and their emissions. Part 3: diesel and gasoline.

Within this review the genotoxicity of diesel and gasoline fuels and emissions is placed in an historical context. New technologies have changed the composition of transportation methods considerably, reducing emissions of many of the components of health concern. The similarity of modern diesel and gasoline fuels and emissions to other carbonaceous fuels and emissions is striking. Recently an International Agency for Research on Cancer (IARC) Working Group concluded that there was sufficient evidence in humans for the carcinogenicity of diesel exhaust (Group 1). In addition, the Working Group found that diesel exhaust has "a positive association (limited evidence) with an increased risk of bladder cancer." Like most other carbonaceous fuel emissions, diesel and gasoline exhausts contain toxic levels of respirable particles (PM <2.5μm) and polycyclic aromatic hydrocarbons. However, the level of toxic components in exhausts from diesel and gasoline emissions has declined in certain regions over time because of changes in engine design, the development of better aftertreatment devices (e.g., catalysts), increased fuel economy, changes in the fuels and additives used, and greater regulation. Additional research and better exposure assessments are needed so that decision makers and the public can decide to what extent diesel and gasoline engines should be replaced.

Improving fuel economy through changes in engine and transmission design

Engine design, transmission design, tractive resistance and driving style all have considerable influence on fuel economy. This paper discusses the influences of the various quantities. Considerable savings in fuel consumption can be achieved either by using a continuously variable transmission which permits current engines to run in their optimum operating condition, or by an engine for which conditions of constant fuel consumption coincide with conditions of constant power. In this case conventional gearboxes will be sufficient.

Lubrication Challenges in Shipping Industry - Reliable Lubrication of Marine Low-Speed Engines

For many decades, the marine industry has been a conservative environment with few changes in legislations and engine design. By the end of previous century, however, the demand for more engine power, followed by increased environmental awareness, triggered tremendous changes in this industry segment. Since the economic recession started several years ago, the marine industry faced an increasing need to reduce operating costs. This resulted in operational changes and triggered the need for new vessel-and engine designs. These changes also had an impact on the lubrication of low-speed marine engines. The selection of the correct cylinder oil and oil feed rate to balance these new conditions in the engine is more important than ever. Chevron has therefore developed its DOT.FAST service to accompany a full range of high quality cylinder oil grades available to guide its customers in achieving reliable and safe operation.

Determination of optimum specific thrust for civil aero gas turbine engines: a multidisciplinary design synthesis and optimisation

A systematic methodology for the determination of optimum specific thrust of civil turbofan engines is presented. The optimum is defined as the specific thrust at which the engine direct operating cost is minimised. Based on publicly available data and clean‐sheet analysis, the developed method provides a rationale for the values of specific thrust found in existing engines and the basis for future designs. The optimum specific thrust determined here complements the thermodynamic optimisation strategy for engine parameters developed in a previous publication by Guha. The process of optimisation thus involves a complex multidisciplinary methodology involving aerodynamics, thermodynamics, structures, system integration, economics, legislations, and other design and operational issues. This study utilises two models: the fixed aircraft rubber engine model which simulates the retrofitting of new engines to a current airframe, and the rubber aircraft rubber engine model which simulates the thermodynamic optimisation of the engines alongside the optimisation of the airframe dimensions. Both models demonstrate that as the design range of the aircraft increases, the optimum value of specific thrust decreases. As fuel prices rise, the optimum value of specific thrust reduces further, taking it to levels where radical changes in engine design and integration would be necessary.

The Effect of Federal Fuel Sulfur Regulations on In-Use Fleets: On-Road Heavy-Duty Source Apportionment

From 2002 to 2007 fuel sulfur content in the Minneapolis/St Paul area decreased from about 325 ppm S to <15 ppm S as a result of EPA regulations. We hypothesized that the reduction in fuel sulfur would result in a reduction of fuel specific heavy duty (HD) particle number emissions for the on-road diesel fleet. Fuel specific emissions were estimated by collecting on-road aerosol data, and exploiting the difference in the relative volumes of HD and light duty (LD) traffic on the roadway. Fuel-specific particle number emissions for HD vehicles were measured to be 9.1 +/- 6.6 x 10(15) and 3.2 +/- 2.8 x 10(15) particles/kg of fuel burned, in 2006 and 2007, respectively, a reduction of 65%. In an earlier study in 2002 particle number emissions for the in-use HD fleet were 4.2 +/- 0.6 x 10(15) particles/km compared to the current measurements of 2.8 +/- 2.1 x 10(15) and 9.9 +/- 8.7 x 10(14) particles/km in 2006 and 2007, respectively. The HD particle mass emission standard remained unchanged from 1994 through 2006 and few 2007 HD vehicles were on the road at the time of this study so the decreases in number observed emissions are more likely due to reductions in the sulfur content of the fuel than to changes in engine and aftertreatment design.

Less wear and oil consumption through helical slide honing of engines by Deutz

Within the scope of continuous development for the Deutz 2012 engines (4 l and 6 l engines) and Tier 3 emissions standards, new developments are required with regard to achieving a new maximum power requirement of 178 kW at 2100 rpm and a higher EGR rate via cooled exhaust gas recirculation. Without implementing engine design changes, the new Tier III constraints are expected to lead to higher wear in the cylinder unit (cylinder bore, piston, piston rings). Together with Deutz, Nagel found a solution for the expected cylinder unit wear on the existing engine, which not only eliminates the potential future wear problem, but also contributes to the important economic considerations of oil consumption and maintenance intervals.

Heat release model for the combustion of diesel oil emulsions in DI diesel engines

Diagnosing the combustion process in internal combustion engines using cylinder pressure, fuel delivery pressure and injector needle lift data is a well-established and widely used procedure in engine and fuel performance tests. Of the models developed, the first law single zone is the simplest and easiest tool to use for quick preliminary analysis of engine performance. It can yield valuable information about the effect of engine design changes, fuel injection system, fuel type and engine operating conditions on the combustion process and engine performance. The model described in this paper is based on a model designed for both SI and CI engines burning liquid and gaseous hydrocarbon fuels. In its current form, the model can be used for diesel engines burning water/diesel emulsions and allows for the effect of the presence of “inert” water in the combustion products on the ratio of specific heats and heating value of the fuel. The output from the model includes the apparent heat release, fraction of fuel burned, fuel burning rate, heat losses, indicated parameters and average gas temperature. Some results of analysis of the performance of a DI diesel engine burning a standard diesel fuel (referred to in the texts as certified diesel fuel CDF, or simply diesel fuel) and diesel oil emulsion (DOE) are presented.

Designing automotive gear oils for the new millennium

AbstractNew engine design changes and ever‐increasing engine requirements make the design of gear oils challenging. A proper understanding of fundamental lubrication theory and formulation knowledge is necessary to develop new gear oils. This paper provides an overview of the fundamentals of lubrication theory and the functions of each additive. Key technical issues facing gear oils are also discussed.

Processing of Nickel-Base Superalloys for Turbine Engine Disc Applications

Nickel-base superalloys used for critical rotating disc components have evolved into advanced, high performance, application-specific materials. The designs of modern turbine machinery applications have dictated a shift in material performance requirements from an emphasis solely on burst and creep strength to the addition of minimized fatigue crack growth rates and component residual stresses. Increased component performance has often resulted in material and process changes that are accompanied by subsequent manufacturing difficulties. For example, increased alloy content has pushed the primary processing route from ingot metallurgy toward powder metallurgy methods. The processing routes required in the manufacture of these materials are equally as complex as the alloys themselves and have a strong influence on the resultant properties of turbine engine discs. Challenges still lie ahead for material and process engineers working on these materials. Both turbine engine design changes and market pressures will mandate novel materials and processes that allow for cost effective solutions for the harsh environment applications these nickel-based superalloys have evolved to fill.

Automotive lubricants for the next millennium

During the first decades of the next millennium, automobile manufacturers will strive to achieve, in the USA, another twofold increase in energy efficiency and tenfold reduction in emission levels. On the way to achieving these goals, automobile manufacturers will be improving efficiency and emissions of internal combustion engines, while minimizing customer servicing requirements, as well as introducing new unconventional engine technologies and gradually changing energy sourcing from oil to gas, and possibly to hydrogen. Numerous supporting technologies, such as electronics, computers, sensors, fuels, catalysts, lubricants, etc., will be involved in contributing to engine system improvements. This paper describes expected improvements and changes in lubricant technology and points out the need for development of “breakthrough” technologies which could satisfy the near‐term requirements and eventually in the long term, in combination with novel surface technologies and engine design changes, lead to fill‐for‐life engine lubrication.

Catalysis science and technology for cleaner transportation fuels

The production of liquid transportation fuels such as gasoline, diesel and jet fuel from petroleum involves the use of a variety of catalytic processes. Although the petroleum refining industry is quite mature, fuel composition requirements continue to evolve with time in response to environmental legislation and changes in engine design. In addition, petroleum feedstocks are becoming heavier and more sour with time. New technology is emerging that allows efficient conversion of natural gas to liquid hydrocarbon fuels. Taken together, these changes pose considerable challenges to the refining industry and significant advances in catalysis are needed to meet the challenge.