Low-emission Engines Research Articles

Grey-Taguchi and ANN based optimization of a better performing low-emission diesel engine fueled with biodiesel

ABSTRACT The current work applies L9 (33) Orthogonal Array (OA) of Taguchi design to obtain an optimum combination of nature of fuel, speed of engine, and load for DI- CI diesel engine that is alternatively fueled with waste cooking oil (WCO) based pure biodiesel (B100) & 20% blend of biodiesel with neat diesel (B20) with an objective to achieve maximum reduction in smoke and NOx emissions and to enhance the output parameters like engine’s heat release, cylinder pressure and brake power with the conceivable dwindling of brake specific fuel consumption of the engine at various load conditions. The optimal input parameters (nature of fuel as B100, speed as 2300 rpm and load as 100%) were specified by the grey relational analysis in such a way that the preferred output results are successfully accomplished. Furthermore, analysis of variance (ANOVA) technique showed that the nature of fuel is the major leading factor with 44.28% impact on the output parameters. The experimental and ANN simulated results at the predicted optimal combination ensured the significant improvements of output response factors, thus validating the use of Grey-Taguchi method in reducing emissions and improving combustion and performance simultaneously.

Effects of Inlet Swirl on Pressure Side Film Cooling of Neighboring Vane Surface

The lean combustion chamber of low NOx emission engines has a short distance between combustion outlet and nozzle guide vanes (NGVs), with strong swirlers located upstream of the turbine inlet to from steady circulation in the combustion region. Although the lean combustion design benefits emission control, it complicates the turbine’s aerodynamics and heat transfer. The strong swirling flow will influence the near-wall flow field where film cooling acts. This research investigates the influence of inlet swirl on the film cooling of cascades. The test cascades are a 1.95 scale model based on the GE-E3 profile, with an inlet Mach number of 0.1 and Reynolds number of 1.48 × 105. Film cooling effectiveness is measured with pressure-sensitive paint (PSP) technology, with nitrogen simulating coolant at a density ratio of near to 1.0. Two neighboring passages are investigated simultaneously, so that pressure and suction side the film cooling effectiveness can be compared. The inlet swirl is produced by a swirler placed upstream, near the inlet, with five positions along the pitchwise direction. These are as follows: blade 1 aligned, passage 1–2 aligned, blade 2 aligned, passage 2–3 aligned and blade 3 aligned. According to the experimental results, the near-hub region is strongly influenced by inlet swirl, where the averaged film cooling effectiveness can differ by up to 12% between the neighboring blades. At the spanwise location Z/Span = 0.7, when the inlet swirl is moved from blade 1 aligned (position 5) to blade 2 aligned (position 3), the film cooling effectiveness in a small area near the endwall can change by up to 100%.

Development of a Friction Welded Joint for Future Industrial Application

Ship transport continues to be the most economical intercontinental means of transportation, which is becoming more and more under observation due to increasing international environmental protection regulations. In order to protect the marine biotope, the government is introducing stricter exhaust emission regulations, which mean the further development of low-emission large engines and thus make the development of new combustion chamber components indispensable. This paper presents FE simulations of a friction welding process for two metallic materials, which are being developed as part of a BMWi joint project for the production of innovative combustion chamber components. In addition, the first results of the simulations and their comparison with real tests are presented.

The Profitability of Disposing of Vehicles Fulfilling the Older Euro Standards in Terms of CO2 Emission

Abstract The automotive market is developing very dynamically. In recent years, we can observe activities of automotive concerns in the production of new models of electric, hybrid and hydrogen vehicles, and conventional cars are supplied with increasingly economical and low-emission engines. There are also increasingly stringent standards related to exhaust emissions from the exhaust system. From September 1, 2018, passenger cars have to comply with the Euro 6d-Temp emission standard and be homologated according to the WLTP test procedure including the WLTC driving cycle and emission measurements in road traffic conditions. The exhaust components measured during the test, such as carbon oxides, nitrogen oxides or hydrocarbons, are toxic to living organisms. However, it seems that the most important issue in the long term may be the value of carbon dioxide emissions, the excess of which poses an ecological threat to the entire planet. The production of new vehicles equipped with modern complicated combustion engines, batteries, fuel cells and electronic devices is associated with a very high emission of this greenhouse gas The authors of the following article, based on their own research, sought to estimate the ecological profitability of replacing a used passenger car meeting the Euro-4 emissions standard for a new vehicle bearing in mind the value of carbon dioxide emissions during vehicle production. The analysis was to indicate how intensive the annual operation of the vehicle should be to make it profitable to recycle and replace it with a modern car with lower emissions considering the global sum of carbon dioxide emissions.

Wall Heat Transfer Analysis of Internal Combustion Engine with Free Piston Linear Motion

The manuscript should contain an abstract. The abstract should be self-contained and citation-free and should not exceed 200 words. The abstract should state the purpose, approach, results and conclusions of the work. The author should assume that the reader has some knowledge of the subject but has not read the paper. Thus, the abstract should be intelligible and complete in it-self (no numerical references); it should not cite figures, tables, or sections of the paper. The abstract should be written using third person instead of first person. Intensive researches are being carried out on the main power generator for free piston linear generator(FPLG) by both the academic and industrial research group due to its potential as a high fuel efficiency and low emission engine. The linear generator, which is a coil and a translator positioned to move linearly back and forth relative to each other. The study investigates the heat transfer data of internal combustion engine with free piston linear motion profile and compared with the conventional reciprocating engine for one cycle motion only. Engine simulation software GT-Power is employed which utilize the 1-D thermodynamic modeling. All parameters for both free-piston engine are set-up to be the same except for the piston motion profile and the injection timing. Both conventional and free piston engine models are built, simulation settings are set up, and simulations are launched in GT-ISE. Once simulation is done, results are viewed in GT-POST, the data collected was analysed and compared to investigate the dictinct effect of piston motion to heat transfer profile and data. The overall trend shows that free piston engine have a lower heat transfer rate throughout majority of the cycle. This finding agrees that due to less time of piston near top dead centre area, heat transfer losses to the wall per cycle are reduced. The heat transfer profile of the free piston also shown distinct feature compared to conventional with rapid increase and decrease of heat transfer rate, followed by a secondary peak of gradual decline of the profile.

An experimental study on the performance and emission characteristics of PCCI-DI engine fuelled with diethyl ether-biodiesel-diesel blends

The possible depletion of fossil fuels has created the need for alternate fuels worldwide and engine developers are prompted to investigate the viability of such fuels. Further, stringent emission norms have created the need for low emission engines. The objective of this work is to evaluate the effect of diethyl ether in biodiesel-diesel blends on the performance and emission characteristics in a Premixed Charge Compression Ignition-Direct Injection (PCCI-DI) engine. Biodiesel obtained from cotton seed oil is used for this study. PCCI-DI engine is operated with main injection and pilot injections with varying percentages of DEE along with 20% biodiesel blended with neat diesel. The emission characteristics show a discernible reduction in emissions (NOx, CO and HC) vis-a-vis biodiesel-diesel blends. Benefits like reduction in the quantum of smoke produced and improvement in Brake thermal efficiency are also noticed in specific cases.

Low emission engine technologies for future tier 3 legislations - options and case studies

Marine emission legislation such as the current IMO Tier II and upcoming IMO Tier III requirements within the revised Marpol Annex VI have been major drivers for performance development of marine engines during the latest years. These requirements have triggered a vast amount of research activity at the engine OEM’s in order to identify and develop the best possible technologies for fulfilling the requirements. A main objective of this research has been to identify the various options available for reducing engine SOx and NOx emissions and to clarify the main criteria engine manufacturers consider to determine the optimum technology. Another objective has been to investigate how ship-owners and operators within the various marine segments are impacted by the new emissions requirements and what key factors they need to consider when identifying the optimum engine technology. Case studies conclude that the optimum solution can vary depending on the vessel application, operating time inside ECAs, as well as prices for fuels and reduction agents. In new-building cases, gas operated engines without after-treatment systems show a strong value proposition as an alternative to liquid fuel engines that require after-treatment solutions - especially for short-haul shipping applications where tighter emission legislations are enforced to a larger extent. Overall, 2-stage turbo charging, LNG, and SCR technologies are concluded to be the most feasible technologies. Generally, lower operating costs can compensate higher capital expenditures meaning that the owner should carefully evaluate the total cost of ownership of the various alternatives, and not consider only the initial capital expenditure. The choice of best technology option depends on a variety of issues which can change over time - such as the operation profile and route of the vessel and commodity prices. Consequently the ship-owner should evaluate the alternative technologies for a wide range of possible scenarios to find a flexible solution that minimizes exposure to risks related to changing boundary conditions. With this research, the reasons why certain emission reduction technologies are preferred to others both from OEM’s and ship-owner’s point of view are quantified and the most feasible technologies for meeting the requirements are identified.

Editorial: Journal of Shipping and Trade

© L p i Journal of Shipping and Trade (JST) is an open access and multi-disciplinary academic journal that focuses both shipping business and transport related areas. Shipping is closely associated with trading activities. JST aims to promote best practices in shipping and to facilitate global trade activities. JST provides a platform for academics and policy makers in the shipping and trade related fields to disseminate research findings and to share the work with others. As a scholarly journal emphasizing shipping and trade related studies, JST is important in establishing communication links among global researchers. JST also aims to contribute to current and emerging issues in shipping and trade as raised by global and regional public bodies (e.g., AIIB, ASEAN, UNCTAD, and World Bank). The first batch of research articles publishing in JST include the inaugural article and the articles of two JST’s special issues. The inaugural article aims to examine the economic impact of transport complex economies (TCEs). TCEs comprise both upstream and downstream firms in the transport chain that conduct shipping and trade-related activities, which can be desirable locations for port users to perform their business activities. To explore TCEs, the authors build a theoretical model to illustrate the relationship between trade facilitation activities and trade costs. The economic outcomes are also examined in the theoretical model. The TCE model is empirically validated by data collected from the World Bank. The findings illustrate the importance of the development of social capital for trade facilitation. The first special issue of JST is the thematic series on “Environmental Impact of Shipping”. The Guest Editors are Thierry Vanelslander and Edwin van Hassel of the University of Antwerp. The first three papers examine emission: the first paper deals with economic impact valuation of environmental impacts of shipping emissions, the second paper looks into low-emission engine technologies in response to environmental shipping regulations, and the third paper makes an economic evaluation of operational strategies for shipping emissions. The fourth paper takes a combined macro– micro approach to compare forecast aggregate demand for LNG with company-level operational strategies. The fifth paper develops an economic model on marine dredging sediments. The final paper provides a concrete application on operational strategy by analysing the impact of slow steaming. With this combination of papers, the special issue provides a snapshot of economic analysis of shipping environmental impacts. Another special issue of JST to be published is the thematic series on “Connecting the World through Global Shipping Networks”. The editorial team members include Jan Hoffmann (United Nations Conference on Trade and development), Gordon Wilmsmeier (Economic Commission for Latin America and the Caribbean), and

Production and Application of Petroleum Oil and Its Alternatives on Internal Combustion Engines

Internal combustion engines are widely used in vehicles, ships, construction machinery, and agricultural machinery due to their reliability, durability, and high efficiency. Furthermore, they will be the main powertrains for above powerplant in the next 50 years according to the wide studies. However, the development of engines is faced with some serious challenges in the future, such as the stringent emission regulations, petroleum energy supply, and greenhouse gas emissions. Therefore, we need to develop some advanced combustion technologies to reduce the pollutant emissions. Meanwhile, to prevent global warming, we need to improve the thermal efficiencies of engines and thereby reduce CO 2 emissions and save petroleum oil. Fuel properties have remarkable effects on engine performance and emissions. High-efficiency and low-emission engines must need the cooperation of high-quality fuels. Meantime, the future advanced engines may need the improved fuel properties which are different from the current gasoline or diesel fuel. In addition, the alternative biofuels have recently gained significant political and scientific interests owing to the concerns about climate change, global energy security, and petroleum supply shortage in the foreseeable future. In this special issue, firstly, N. Li et al. from State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, present the improvement on production of petroleum oil. Secondly, C. Jin and Z.Q. Zheng from Tianjin University and B. Yang et al. from Shandong University of Technology present the need for engine fuel properties for future advanced combustionmodes such as homogeneous charge compression ignition and low temperature combustion. Finally, L. Dong et al. from Civil Aviation University of China and F. Zhang et al. from Hunan University present how to achieve high-efficiency and clean combustion based on cooperated control of fuel, oil, and engines. Finally, we hope this special issue can give you some help to understand the tight relationship between petroleum and engines and to know the future engine combustion technologies and the needs for future engine fuels and oil.

The Chances for Reduction of Vibrations in Mechanical System with Low-Emission Ships Combustion Engines

"Development of diesel engines is focused on reduction of exhaust gas emissions, increase of efficiency of the fuel mixture combustion and decrease of fuel consumption. Such engines are referred to as low-emission engines. Lowengines trends bring higher engine power outputs, torques and also increase of vibrations and noisiness level. In order to reduce these vibrations of diesel engines, it is necessary to apply different dynamical elements, which are able to increase an adverse impact of exciting amplitudes. One of the results is application of a pneumatic dual-mass flywheel. The pneumatic dual-mass flywheel is a dynamical element that consists of two masses (the primary and the secondary mass), which are jointed together by means of a flexible interconnection. This kind of the flywheel solution enables to change resonance areas of the mechanical system which consequently leads to reduction of vibrations."

205 トラップグリース由来燃料を用いた重油焚きディーゼル発電における環境負荷特性(廃棄物発電・環境マネージメント手法)

Effective utilization of waste bio-oil such as fried oil is important for development of low emission engine. Grease trap oil collected from private sewerage system is one of the waste bio-oil and is so dirty and high viscosity that direct applying to the engine is difficult. In this work, however, properties of diesel combustion using mixture of heavy oil and grease trap oil (GTO) was discussed although simply filtration of GTO was carried out. Moreover, environmental burden applying mixture of heavy oil and GTO to commercial diesel generation was investigated. Fuel supply of the mixture differed only slightly with variation of GTO composition. In case of relatively high electric load, the fuel supply decreased when the composition of GTO was more than 30 %. It is thought that the viscosity influences the characteristics of fuel injection. NOx and SO_2 emission decreased with increase in the composition of GTO. On the contrary, concentration of CO in exhaust gas also decrease. The properties of NOx emission give an indication of reduction in temperature with increase in the composition of GTO but that of CO emission shows improvement of combustion state. On the other hand, the properties of SO_2 emission were lower than estimation values calculated from sulfur contents of these fuels.

Estimation on LTO Cycle Emissions from Aircrafts at Civil Airports

A calculation method on pollutant emission inventory is established based on the standard LTO cycle of the International Civil Aviation Organization (ICAO) by analyzing the factors influencing aircraft engine emissions at civil aviation airports. For a certain airport in China, the emissions of HC, CO, NOx and SO2per hour for a whole day from the aircraft engines are calculated, and the variations of various pollutant emissions with time are analyzed based on the air traffic data, the civil aviation fleet composition, the flight detailed take-off and landing information at the airport, and ICAO engine emission data bank. It’s found that the variations of the pollutant emissions with time are different, in which, the emissions of HC and CO are significantly influenced by the frequency of flight arrival at airport, however, the emission of NOx is influenced by the frequency of flight departure from airport greatly, and the emission of SO2is influenced by the total frequency of flight arrival at and departure from airport comprehensively. For solving the problem of local high-emission time, some solutions are suggested, such as equipping aircrafts with low-emission engines or optimizing the flight schedule.

Design of Variable Valve Agency for Gasoline Engine Based on AVLBOOST

As an important technological means for engines’ low emission with high efficiency, variable valve agency is widely applied in the new-type machine’s R&D and the old-type machine’s modification. This paper applies AVL BOOST one-dimensional simulation software to the working process of the small displacement electronic control gasoline engine and proceeds with the analog simulating calculation. The data error between the calculated result and the original experiment one is less than 5%, so the calculation precision meets the requirements. As formulating simulation study programs and analyzing the valve timing parameters’ impact on the low-emission electronic control gasoline engine’s performances, this paper finds the intake duration angle, the exhaust advance angle, and the valve overlap, all receive big impacts; the original machine’s valve timing optimizes the treatment of working conditions with high speed while sacrificing the power performance of low-speed working conditions. On this basis, this paper designs the variable valve mechanism, and improves the original machine’s medium-and-low rotating speed’s torque by 10% or so.

The probabilistic nature of ignition of turbulent highly-strained lean premixed methane-air flames for low-emission engines

The probabilistic nature of ignition of turbulent highly-strained lean premixed flames has been investigated. Two flow configurations have been considered in this study; counter-flow and bluff-body flames. Different successful and non-successful ignition events in both flows have been observed directly with high-speed imaging. In addition, the flame front structure during the flame propagation following the ignition has been observed using OH-PLIF technique. Moreover, the ignition probability has been measured in both flows with different equivalence ratios and flow velocities. It has been found that high bulk velocities decrease the ignition probability in all locations and for all flames. For counter-flow flames, ignition is sometimes possible even in locations where there is negligible probability of finding flammable mixture and is sometimes impossible in locations with high probability of flammable flow. The edge flame propagation speed has also been detected in this type of flames. For bluff-body flames, the flame propagation behavior following the spark ignition depends mainly on the location of the spark in respect to the recirculation zones. Furthermore, the flame inside the side recirculation zone (SRZ) quenches soon after the whole flame lights-up. Failed ignition has been viewed close to the extinction flow conditions of the flame. Igniting the flame away from the extinction conditions results in 100% ignition probability regardless of the ignition location. However, close to extinction, ignition probability decreases gradually and achieving ignition is not possible at all outside the central recirculation zone (CRZ). The obtained ignition probability contours of both flows have been compared with the previously-studied ignition probability contours of turbulent non-premixed flames of the same burners.

Effect of Change in Fuel Compositions and Heating Value on Ignition and Performance for Siemens SGT-400 Dry Low Emission Combustion System

The influence of changes in fuel composition and heating value on the performance of an industrial gas turbine combustor was investigated. The combustor tested was a single cannular combustor for Siemens SGT-400 13.4 MW dry low emission engine. Ignition, engine starting, emissions, combustion dynamics, and flash back through burner metal temperature monitoring were among the parameters investigated to evaluate the impact of fuel flexibility on combustor performance. Lean ignition and extinction limits were measured for three fuels with different heat values in term of Wobbe Index (WI): 25, 28.9, and 45 MJ/Sm3 (natural gas). The test results show that the air fuel ratio at lean ignition/extinction limits decreases and the margin between the two limits tends to be smaller as fuel heat value decreases. Engine start tests were also performed with a lower heating value fuel and results were found to be comparable to those for engine starting with natural gas. The combustor was further tested in a high pressure air facility at real engine operating conditions with different fuels covering WIs from 17.5 to 70 MJ/Sm3. The variation in fuel composition and heating value was achieved in a gas mixing plant by blending natural gas with CO2, CO, N2, and H2 (for the fuel with WI lower than natural gas) and C3H8 (for the fuel with WI higher than natural gas). Test results show that a benefit in NOx reduction can be seen for the lower WI fuels without H2 presence in the fuel and there are no adverse impacts on combustor performance except for the requirement of higher fuel supply pressure, however, this can be easily resolved by minor modification through the fuel injection design. Test results for the H2 enriched and higher WI fuels show that NOx, combustion dynamics and flash back have been adversely affected and major change in burner design is required. For the H2 enriched fuel, the effect of CO and H2 on combustor performance was also investigated for the fuels having a fixed WI of 29 MJ/Sm3. It is found that H2 dominates the adverse impact on combustor performance. The chemical kinetic study shows that H2 has significant effect on flame speed change and CO has significant effect on flame temperature change. Although the tests were performed on the Siemens SGT-400 combustion system, the results provide general guidance for the challenge of industrial gas turbine burner design for fuel flexibility.

An Experimental Methodology for the Reconstruction of Three-Dimensional Acoustic Pressure Fields in Ducts

The claim for low emission engines, imposed by strict environmental legislation, has prompted the aeronautical industry to reduce both noise emission and pollution by using lean combustion technology. These engines are often affected by acoustic instabilities that can compromise their correct functioning. A 3D acoustic wave field investigation is increasingly relevant for a correct design and comprehension of this kind of phenomena. Numerical codes are widely used for this type of analysis but an experimental validation is still required due to the complexity of the real phenomena involved in acoustic generation and propagation. While the wall acoustic pressure can be easily measured, very few examples of radial measurement for a 3D analysis can be found in research on this subject. This paper presents an example of a radial measurement of a 3D acoustic pressure field by means of a waveguide probe based on a 1/4" pressure microphone. In particular, several probe geometries were designed and calibrated on a specialized test rig. In order to verify the adopted methodology, the acoustic 3D pressure fields of two simplified geometries were measured and compared with those from a theoretical model describing the actual conditions of the test rig.

Optimization of structure and combustion system for a low-emission light-duty diesel engine

Optimization of structure and combustion system for a low-emission light-duty diesel engine

NASA Environmentally Responsible Aviation Project Develops Next-Generation Low-Emissions Combustor Technologies (Phase I)

NASA’s Environmentally Responsible Aviation (ERA) Project is working with industry to develop the fuel flexible combustor technologies for a new generation of low-emissions engine targeted for the 2020 timeframe. These new combustors will reduce Nitrogen Oxide (NOx) emissions to half of current state-of-the-art (SOA) combustors, while simultaneously reducing noise and fuel burn. The purpose of the low NOx fuel-flexible combustor research is to advance the Technology Readiness Level (TRL) and Integration Readiness Level (IRL) of a low NOx, fuel flexible combustor to the point where it can be integrated in the next generation of aircraft. To reduce project risk and optimize research benefit NASA chose to found two Phase 1 contracts. The first Phase 1 contracts went to engine manufactures and were awarded to: General Electric Company, and Pratt & Whitney Company. The second Phase 1 contracts went to fuel injector manufactures Goodrich Corporation, Parker Hannifin Corporation, and Woodward Fuel System Technology. In 2012, two sector combustors were tested at NASA’s ASCR. The results indicated 75% NOx emission reduction below the 2004 CAEP/6 regulation level.

Piezoelectric sensors to monitor lubricant film thickness at piston–cylinder contacts in a fired engine

The contact between the piston ring and cylinder liner is the most important sealing interface in an automotive engine. Understanding the contact interactions and lubricant film formation at this interface is crucial for the development of fuel-efficient and low emission engines. This article outlines the development of an ultrasonic approach to enable non-invasive measurement of the lubricant film thickness formed between piston and cylinder wall of a fired engine. The sensor system consisted of a series of small, low cost piezoelectric elements which were bonded to the external surface of a four-stroke, single-cylinder engine. Each element could be individually energised with a short duration voltage pulse and reflections from the cylinder inner bore recorded. By using high frequency pulsing and data capture it proved possible to image individual ring and skirt contacts at full engine speeds. These captured reflections were processed to give lubricant film thickness directly and without the need for independent calibration. The results show good repeatability between cycle sets at specific running conditions. The lubricant films at each of the ring contacts can be measured at sufficient resolution such that individual rails of the oil control ring can be monitored. In addition, the film generated at the skirt was measured, the results from which, suggest the occurrence of ‘piston slap’ and highlight the potential for this ultrasonic method to enable indirect measurements of piston secondary dynamics.

A New Air-Fuel Ratio Control for a High-Efficiency and Low-Emission Engine

Accurate air-fuel ratio control is one of the subjects of low-emission technologies for gasoline engines, and can maximize the conversion efficiency of a three-way catalyst by controlling the air-f...