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1
Haddad, S. D. "Piston Motion and Thermal Loading Analyses of Two-Stroke and Four-Stroke Cycle Engines for Locomotives." Journal of Engineering for Gas Turbines and Power 111, no. 3 (July 1, 1989): 536–42. http://dx.doi.org/10.1115/1.3240288.
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Two-stroke cycle and four-stroke cycle diesel engines are in use in rail traction, with the four-stroke cycle design dominating the field. Cycle simulations using computer programs have shown that the conventional two-stroke cycle is somewhat inferior to its four-stroke cycle counterpart in combustion efficiency and thermal loading. Research at Sulzer concluded that the conventional two-stroke cycle engine is not very suitable for locomotive application. A survey by Ricardos, based on an investigation of engines in current production for traction application, suggested that there are potentials in two-stroke cycle design. This paper presents a summary of the results of a research project concerned with comparison of two well-proven typical locomotive diesel engines, one with a two-stroke cycle and the other with a four-stroke cycle. Performance, mechanical loading, thermal loading, and vibration were chosen as parameters to be investigated to provide information on the status of the two cycles in relation to power range, fuel consumption, reliability, and durability, with a view to assisting the users of locomotive engines to make the correct choice.
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MITIANIEC, Władyslaw, and Konrad BUCZEK. "Modification of four-stroke engine for operation in two-stroke cycle for automotive application." Combustion Engines 162, no. 3 (August 1, 2015): 3–12. http://dx.doi.org/10.19206/ce-116860.
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The main disadvantages of two-stroke engines such a big fuel consumption and big emission of hydrocarbons or carbon monoxide can be reduced by new proposal of design of two stroke engine based on four stroke engines. The paper describes the operation of high supercharged spark ignition overhead poppet valve two-stroke engine, which enables to achieve higher total efficiency and exhaust gas emission comparable to four-stroke engines. The work of such engines is possible by proper choice of valve timings, geometrical parameters of inlet and outlet ducts and charge pressure. The engine has to be equipped with direct fuel injection system enabling lower emission of pollutants. The work is based on theoretical considerations and engine parameters are determined on the simulation process by use GT-Power program and CFD program for different engine configurations. The initial results included in the paper show influence of valve timing on engine work parameters and predicted exhaust gas emission. The simulation results show that the nitrogen oxides are considerably reduced in comparison to four-stroke engines because of higher internal exhaust gas recirculation. The innovation of this proposal is applying of variable valve timing with turbocharging system in the two-stroke engine and obtaining a significant downsizing effect. The conclusions shows the possibilities of applying two-stroke poppet valve engine as a power unit for transportation means with higher total efficiency than traditional engines with possible change of engine operation in two modes: two- and four stroke cycles. The main disadvantages of two-stroke engines such a big fuel consumption and big emission of hydrocarbons or carbon monoxide can be reduced by new proposal of design of two stroke engine based on four stroke engines. The paper describes the operation of high supercharged spark ignition overhead poppet valve two-stroke engine, which enables to achieve higher total efficiency and exhaust gas emission comparable to four-stroke engines. The work of such engines is possible by proper choice of valve timings, geometrical parameters of inlet and outlet ducts and charge pressure. The engine has to be equipped with direct fuel injection system enabling lower emission of pollutants. The work is based on theoretical considerations and engine parameters are determined on the simulation process by use GT-Power program and CFD program for different engine configurations. The initial results included in the paper show influence of valve timing on engine work parameters and predicted exhaust gas emission. The simulation results show that the nitrogen oxides are considerably reduced in comparison to four-stroke engines because of higher internal exhaust gas recirculation. The innovation of this proposal is applying of variable valve timing with turbocharging system in the two-stroke engine and obtaining a significant downsizing effect. The conclusions shows the possibilities of applying two-stroke poppet valve engine as a power unit for transportation means with higher total efficiency than traditional engines with possible change of engine operation in two modes: two- and four stroke cycles.
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Shokrollahihassanbarough, Farzad, Ali Alqahtani, and Mirosław Wyszynski. "Thermodynamic simulation comparison of opposed two-stroke and conventional four-stroke engines." Combustion Engines 162, no. 3 (August 1, 2015): 78–84. http://dx.doi.org/10.19206/ce-116867.
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Today’s technology leveraging allows OP2S (Opposed Piston 2-Stroke) engine to be considered as an alternative for the conventional four-stroke (4S) engines as mechanical drive in various applications, mainly in transportation. In general, OP2S engines are suited to compete with conventional 4-stroke engines where power-to-weight ratio, power-to-bulk volume ratio and fuel efficiency are requirements. This paper does present a brief advent, as well as the renaissance of OP2S engines and the novel technologies which have been used in the new approach. Also precise thermodynamic benefits have been considered, to demonstrate the fundamental efficiency advantage of OP2S engines. Hence, simulations of two different engine configurations have been taken into consideration: a one-cylinder opposed piston engine and two-cylinder conventional piston four-stroke engine. In pursuance of fulfilling this goal, the engines have been simulated in AVL Boost™ platform which is one of the most accurate Virtual Engine Tools, to predict engine performance such as combustion optimization, emission and fuel consumption. To minimize the potential differences of friction losses, the bore and stroke per cylinder are taken as constant. The closed-cycle performance of the engine configurations is compared using a custom analysis tool that allows the sources of thermal efficiency differences to be identified and quantified. As a result, brake thermal efficiency, power and torque of OP2S engine have been improved compared to conventional engines while emission concern has been alleviated.
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Kenny, R. G. "Developments in Two-Stroke Cycle Engine Exhaust Emissions." Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 206, no. 2 (April 1992): 93–106. http://dx.doi.org/10.1243/pime_proc_1992_206_165_02.
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This paper is concerned with the exhaust emissions from two-stroke cycle spark ignition engines and the means being investigated to reduce them. The simple two-stroke engine has inherently low levels of NOx emissions and high levels of hydrocarbon emissions. The reasons for these emissions characteristics are explained by reference to the open literature. The two-stroke engine is used in a wide range of applications including low-cost, low-output mopeds and high-performance motorcycles. More recently there has been a resurgence of interest in the two-stroke as an alternative to the four-stroke engine for automotive use. A number of the recently reported approaches to emissions control are reviewed, including the use of exhaust oxidation catalysts in simple low-cost engines and direct fuel injection on more costly, multi-cylinder engines.
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Egorov, Aleksey, Natalya Lysyannikova, Yuri Kaizer, Vasiliy Tyukanov, Alexander Kuznetsov, Taalaibek Matkerimov, Helena Tsygankova, and Katharina Tretyakova. "Thermodynamic work in inline piston gasoline engines as a function of crank angle." E3S Web of Conferences 164 (2020): 03021. http://dx.doi.org/10.1051/e3sconf/202016403021.
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The purpose of this research work is to identify the laws of thermodynamic operation in the theoretical cycles of four-stroke inline piston gasoline internal combustion engines (ICE). The main results: dependence of the thermodynamic operation of the working body of ICE in theoretical cycles of four-stroke inline piston gasoline engines as a function of the angle of rotation of the crankshaft; regularities of uneven generation of positive thermodynamic operation in the theoretical cycle of four-stroke inline one-, two-, three -, five-cylinder piston gasoline ICE; regularities of the alternating character of thermodynamic operation in the theoretical cycles of inline four-stroke one -, two -, three -, four - and five-cylinder gasoline piston ICE; regularities of positive thermodynamic operation during the entire theoretical cycle of four-stroke inline six-and eight-cylinder piston gasoline ICE; conditions for uniform pulsation of thermodynamic operation during the entire theoretical cycle of four-stroke inline piston gasoline ICE - the product of the crankshaft angle by the number of cylinders must be 720o (four-cylinder inline with a crankshaft angle of 180o, six-cylinder inline with a crankshaft angle of 120o, eight-cylinder inline with a crankshaft angle of 90o).
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Weerasinghe, Rohitha, and Sandra Hounsham. "Small Engines as Bottoming Cycle Steam Expanders for Internal Combustion Engines." Journal of Combustion 2017 (2017): 1–8. http://dx.doi.org/10.1155/2017/1742138.
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Heat recovery bottoming cycles for internal combustion engines have opened new avenues for research into small steam expanders (Stobart and Weerasinghe, 2006). Dependable data for small steam expanders will allow us to predict their suitability as bottoming cycle engines and the fuel economy achieved by using them as bottoming cycles. Present paper is based on results of experiments carried out on small scale Wankel and two-stroke reciprocating engines as air expanders and as steam expanders. A test facility developed at Sussex used for measurements is comprised of a torque, power and speed measurements, electronic actuation of valves, synchronized data acquisition of pressure, and temperatures of steam and inside of the engines for steam and internal combustion cycles. Results are presented for four engine modes, namely, reciprocating engine in uniflow steam expansion mode and air expansion mode and rotary Wankel engine in steam expansion mode and air expansion mode. The air tests will provide base data for friction and motoring effects whereas steam tests will tell how effective the engines will be in this mode. Results for power, torque, and p-V diagrams are compared to determine the change in performance from air expansion mode to steam expansion mode.
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Harbach, James A., and Vito Agosta. "Effects of Emulsified Fuel on Combustion in a Four-Stroke Diesel Engine." Journal of Ship Research 35, no. 04 (December 1, 1991): 356–63. http://dx.doi.org/10.5957/jsr.1991.35.4.356.
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While the use of emulsified fuel in diesel engines has been an area of much research interest in recent years, the promising results reported in laboratories have not been easy to reproduce in commercial practice. Many of these studies have only measured external effects such as fuel consumption and exhaust emissions. A single-cylinder research engine was operated with water/diesel fuel oil and hydrous ethanol/diesel fuel oil emulsions of varying percentages. Crank angle, cylinder pressure and injector lift were recorded electronically over 50 engine cycles, permitting calculation of the mean and standard deviation of key combustion parameters. The results showed decreased fuel consumption and increased ignition delay, peak cylinder pressure and maximum cylinder pressure rise rate for emulsion operation. While the standard deviation data showed little change in cycle-to-cycle variation for wateremulsion operation, increases of over 200 percent were measured for operation at ethanol amounts over 20 percent.
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Kutlar, Osman Akin, and Fatih Malkaz. "Two-Stroke Wankel Type Rotary Engine: A New Approach for Higher Power Density." Energies 12, no. 21 (October 26, 2019): 4096. http://dx.doi.org/10.3390/en12214096.
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The Wankel engine is a rotary type of four-stroke cycle internal combustion engine. The higher specific power output is one of its strong advantages. In Wankel rotary engine, every eccentric shaft revolution corresponds to one four-stroke cycle, whereas conventional reciprocating engine fulfills four-stroke cycle in two crankshaft revolutions. This means the power stroke frequency is twice that of conventional engines. Theoretically, application of two-stroke cycle on Wankel geometry will duplicate the power stroke frequency. In this research, a single-zone thermodynamic model is developed for studying the performance characteristic of a two-stroke Wankel engine. Two different port timings were adapted from the literature. The results revealed that late opening and early closing port geometry (small opening area) with high supercharging pressure has higher performance at low speed range. However, as the rotor speed increases, the open period of the port area becomes insufficient for the gas exchange, which reduces power performance. Early opening and late closing port geometry (large opening area) with supercharging is more suitable in higher speed range. Port timing and area, charging pressure, and speed are the main factors that characterize output performance. These preliminary results show a potential for increasing power density by applying two-stroke cycle of the Wankel engine.
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Finneran, Joshua, Colin P. Garner, Michael Bassett, and Jonathan Hall. "A review of split-cycle engines." International Journal of Engine Research 21, no. 6 (July 19, 2018): 897–914. http://dx.doi.org/10.1177/1468087418789528.
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This article reviews split-cycle internal combustion engine designs. The review includes historical work, assessment of prototypes and discussion of the most recent designs. There has been an abundance of split-cycle engine designs proposed since the first in 1872. Despite this, very few prototypes exist, and no split-cycle engines are reported to be in series production. The few split-cycle prototypes that have been developed have faced practical challenges contributing to limited performance. These challenges include air flow restrictions into the expansion cylinder, late combustion, thermal management issues, and mechanical challenges with the crossover valve actuation mechanism. The main promoted advantage of split-cycle engines is the increased thermal efficiency compared to conventional internal combustion engines. However, an efficiency improvement has not thus far been demonstrated in published test data. The thermodynamic studies reviewed suggest that split-cycle engines should be more efficient than conventional four-stroke engines. Reasons why increased thermal efficiency is not realised in practice could be due to practical compromises, or due to inherent architectural split-cycle engine design limitations. It was found that the number of split-cycle engine patents has increased significantly over recent years, suggesting an increased commercial interest in the concept since the possibility of increased efficiency becomes more desirable and might outweigh the drawbacks of practical challenges.
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Amit, Mr. "Performance Study of Air Driven Engine Being Modified From Conventional Four Stroke Engine without Cam Modification." International Journal of Engineering and Advanced Technology 10, no. 2 (December 30, 2020): 250–54. http://dx.doi.org/10.35940/ijeat.b2076.1210220.
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This research presents a novel mechanism to convert a conventional100-cc four stroke driven engine into a 2 stroke compressed air driven engine without doing any modifications in the cam shaft. This allows for a faster valve operation & also helping the existing engines to be converted into air driven engines with removal of intake and exhaust manifold and also provides a platform to curb the growing menace of air pollution by using the existing old engines to be used as air driven engine. Also, cycle of operation of the Air Engine has been representedon P-V diagram and theoretical efficiency has been calculated which is a function of pressure ratio and temperature, and comes out to be around 80 percent (@ Prr. Ratio of 10& Temp of 550K). Variation of rpm with percentage valve opening is seen at different pressure ratios and the maximum speed of the engine (after doing said modifications and running through compressed air)is observed to be 1573 rpm at a pressure of 9 bar with the developed mechanism for the existing 4 stroke maestro engine.
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Herrmann, Samara, Macklini Dalla Nora, and Thompson Diordinis Metzka Lanzanova. "Development of a Two-Stroke Cycle Engine for Use in the Agricultural Aviation Sector." Journal of Aerospace Technology and Management, no. 12 (November 21, 2020): 52–61. http://dx.doi.org/10.5028/jatm.cab.1155.
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Reciprocating internal combustion engines have wide application in agricultural, recreational and experimental aircraft, resulting from their low cost and less complex maintenance compared to other engines. Thus, this work analyzed the performance of a conventional four-stroke engine operating in the two-stroke cycle by means of direct fuel injection and mechanical air supercharging. The use of a supercharger was essential in this design to provide adequate gas exchange inside the cylinder during the long valve overlap required, while direct fuel injection made it possible to reduce the short circuit of air-fuel mixture to the exhaust. Due to the double ignition frequency compared to a four-stroke engine, it was possible to obtain a large power density (40 kW/L) at a speed of 2400 rpm, also a specific fuel consumption of 270 g/kWh with gasoline and 400 g/kWh with ethanol. The use of ethanol in replacement of gasoline made it possible to operate at full load (160 Nm/L) at 800 rpm without the occurrence of knocking combustion.
12
Hernández, A. Calvo, J. M. M. Roco, A. Medina, and S. Velasco. "An irreversible and optimized four stroke cycle model for automotive engines." European Journal of Physics 17, no. 1 (January 1, 1996): 11–18. http://dx.doi.org/10.1088/0143-0807/17/1/003.
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Cao, L., H. Zhao, X. Jiang, and N. Kalian. "Mixture formation and controlled auto-ignition combustion in four-stroke gasoline engines with port and direct fuel injections." International Journal of Engine Research 6, no. 4 (August 1, 2005): 311–29. http://dx.doi.org/10.1243/146808705x30611.
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Controlled auto-ignition (CAI) combustion, also known as homogeneous charge compression ignition (HCCI) can be achieved by trapping residuals with early exhaust valve closure in both port and direct fuel injection four-stroke gasoline engines. A multi-cycle three-dimensional engine simulation program has been developed and applied to study the effect of injection on in-cylinder mixing and CAI combustion. The full engine cycle simulation, including complete gas exchange and combustion processes, was carried out over several cycles in order to obtain the stable cycle for analysis. The combustion models used in the present study are based on the Shell auto-ignition model and the characteristic-time combustion model, both of which have been modified to take the high level of residual gas into consideration. A liquid sheet break-up spray model was used for the droplet break-up processes. The analyses show that the injection timing plays an important role in affecting the in-cylinder air/fuel mixing and mixture temperature, which in turn affects the CAI combustion and engine performance. In comparison with the port fuel injection case, an early direct injection at exhaust valve closure can lead to higher load and lower fuel consumption.
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Heywood, John B. "Fluid Motion Within the Cylinder of Internal Combustion Engines—The 1986 Freeman Scholar Lecture." Journal of Fluids Engineering 109, no. 1 (March 1, 1987): 3–35. http://dx.doi.org/10.1115/1.3242612.
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The flow field within the cylinder of internal combustion engines is the most important factor controlling the combustion process. Thus it has a major impact on engine operation. This paper reviews those aspects of gas motion into, within, and out of the engine cylinder that govern the combustion characteristics and breathing capabilities of spark-ignition engines and compression-ignition or diesel engines. Necessary background information on reciprocating engine operating cycles, the primary effect of piston motion and the spark-ignition and diesel engine combustion processes is first summarized. Then the characteristics of flow through inlet and exhaust valves in four-stroke cycle engines, and through ports in the cylinder liner in two-stroke cycle engines are reviewed. These flows govern the airflow through the engine, and set up the in-cylinder flow that controls the subsequent combustion process. The essential features of common in-cylinder flows—the large scale rotating flows set up by the conical intake jet, the creation and development of swirl about the cylinder axis, the flows produced during compression due to combustion chamber shape called squish, flow during the combustion process, and two-stroke scavenging flows—are then described. The turbulence characteristics of these flows are then defined and discussed. Finally, flow phenomena which occur near the walls, which are important to heat transfer and hydrocarbon emissions phenomena, are reviewed. The primary emphasis is on developing insight regarding these important flow phemomena which occur within the cylinder. To this end, results from many different research techniques—experimental and computational, established and new—have been used as resources. It is the rapidly increasing convergence of engine flow information from these many sources that make this an exciting topic with promise of significant practical contributions.
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Caceres, D., J. R. Reisel, A. Sklyarov, and A. Poehlman. "Exhaust Emission Deterioration and Combustion Chamber Deposit Composition Over the Life Cycle of Small Utility Engines." Journal of Engineering for Gas Turbines and Power 125, no. 1 (December 27, 2002): 358–64. http://dx.doi.org/10.1115/1.1496773.
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In this study, a laboratory test procedure to mimic the life cycle of the small air-cooled engines in field operation is developed. A characterization of exhaust emissions over the life cycle of the engines is achieved with special focus given to the hydrocarbon emissions. Both Briggs and Stratton four-stroke (four-cycle) overhead-valve and side-valve engines with a nominal power output of 3.7 kW (5 hp) are used in this study. Different levels of emissions are observed for each type of engine configuration, and it is noted that the hydrocarbon emissions changed more than CO or NOx emissions. These data support the idea that combustion chamber deposits (CCD) are a significant cause of deteriorating emissions. Chemical analysis techniques are applied to the CCD, and it is found that the deposits consist primarily of polynuclear aromatic compounds and unsaturated hydrocarbons.
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Seithe, Grusche J., Alexandra Bonou, Dimitrios Giannopoulos, Chariklia A. Georgopoulou, and Maria Founti. "Maritime Transport in a Life Cycle Perspective: How Fuels, Vessel Types, and Operational Profiles Influence Energy Demand and Greenhouse Gas Emissions." Energies 13, no. 11 (May 29, 2020): 2739. http://dx.doi.org/10.3390/en13112739.
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A “Well-to-Propeller” Life Cycle Assessment of maritime transport was performed with a European geographical focus. Four typical types of vessels with specific operational profiles were assessed: a container vessel and a tanker (both with 2-stroke engines), a passenger roll-on/roll-off (Ro-Pax) and a cruise vessel (both with 4-stroke engines). All main engines were dual fuel operated with Heavy Fuel Oil (HFO) or Liquefied Natural Gas (LNG). Alternative onshore and offshore fuel supply chains were considered. Primary energy use and greenhouse gas emissions were assessed. Raw material extraction was found to be the most impactful life cycle stage (~90% of total energy use). Regarding greenhouse gases, liquefaction was the key issue. When transitioning from HFO to LNG, the systems were mainly influenced by a reduction in cargo capacity due to bunkering requirements and methane slip, which depends on the fuel supply chain (onshore has 64% more slip than offshore) and the engine type (4-stroke engines have 20% more slip than 2-stroke engines). The combination of alternative fuel supply chains and specific operational profiles allowed for a complete system assessment. The results demonstrated that multiple opposing drivers affect the environmental performance of maritime transport, a useful insight towards establishing emission abatement strategies.
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Konyukov, Vyacheslav Leontievich. "Comparative analysis of marine diesel engines by ultimate efficiency increase under direct air flow control." Vestnik of Astrakhan State Technical University. Series: Marine engineering and technologies 2021, no. 2 (May 31, 2021): 43–54. http://dx.doi.org/10.24143/2073-1574-2021-2-43-54.
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The paper presents a comparative analysis of the operational parameters and parameters of marine diesel engines obtained as a result of computational and theoretical studies with direct control of air flow using an adjustable turbocharger nozzle to ensure the maximum allowable efficiency of diesel engines. The objects under study are: two-stroke marine diesel engine, operating on the screw characteristics; marine four-stroke diesel working on the screw characteristics; marine four-stroke diesel working on the load characteristics. As a result of the rotation of the blades of the adjustable nozzle in the direction of reducing the angle of their installation the diesel engine efficiency increases. However, the maximum pressure of the cycle also increases, the pressure drop decreases during purging the cylinders, the effective angle of gas exit from the turbine nozzle decreases, and the compressor's surge stability margin changes. There has been studied the design potential of diesel engines for the maximum increase in their efficiency, which made it possible to accept the stable operation of the compressor in all the studied modes. In the course of the research, boundary values were found for the maximum pressure of the diesel cycle, the pressure drop for purging the cylinders and the effective angle of flow exit from the nozzle apparatus, beyond which the specified parameters did not go beyond all the studied modes of operation of diesels. Taking into account the limitations of the greatest potential for improving efficiency in the equity modes of loads has a four-stroke diesel engine, operating on the screw characteristics, the smallest capacity is the same petrol, but working on the load characteristics.
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Volpato, Carlos Eduardo Silva, Alexon do Prado Conde, Jackson Antonio Barbosa, and Nilson Salvador. "Performance of cycle diesel engine using Biodiesel of olive oil (B100)." Ciência e Agrotecnologia 36, no. 3 (June 2012): 348–53. http://dx.doi.org/10.1590/s1413-70542012000300011.
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Biodiesel is a renewable fuel derived from vegetable oils used in diesel engines, in any proportion with petroleum diesel, or pure. It is produced by chemical processes, usually by transesterification, in which the glycerin is removed. The objective of this study was to compare the performance of a four stroke, four cylinder diesel cycle engines using either olive (B100) biodiesel oil or diesel oil. The following parameters were analyzed: effective and reduced power, torque, specific and hourly fuel consumption, thermo-mechanical and volumetric efficiency. Analysis of variance was performed on a completely randomized design with treatments in factorial and the Tukey test applied at the level of 5%. Five rotation speeds were researched in four replications (650, 570, 490, 410, 320 and 240 rpm). The engine fed with biodiesel presented more satisfactory results for torque, reduced power and specific and hourly consumptions than that fed with fossil diesel.
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Sharke, Paul. "Otto or Not, Here it Comes." Mechanical Engineering 122, no. 06 (June 1, 2000): 62–66. http://dx.doi.org/10.1115/1.2000-jun-4.
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This article highlights the new ignition schemes for Otto cycle engines that seem to be bound for extinction. Ever since Nicolaus Otto demonstrated the first working four-stroke engine in 1876, engineers have been struggling to come up with ways to sidestep a fundamental limitation of an otherwise stellar design. The reciprocating engine is capable of generating high pressure with reliable sealing, but the volume swept out by the piston has had to remain fixed. Small engines use less internal reciprocating mass than large ones, so the energy to overcome friction decreases as size drops. Small engines are lighter than big ones, too. By recirculating exhaust gases back into the combustion chamber, however, Mitsubishi uses the exhaust to reduce NOx. Because the air-to-fuel ratio is so high, the exhaust gases, which normally hinder combustion, can be as much as 70 percent of the cylinder volume. At the same time, Mitsubishi uses a lean NOx catalytic converter.
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Mirzaei, M., S. M. Hashemi, B. Saranjam, and A. Binesh. "Two-Zone Simulation of an Axial Vane Rotary Engine Cycle." International Journal of Applied Mechanics and Engineering 26, no. 2 (June 1, 2021): 143–59. http://dx.doi.org/10.2478/ijame-2021-0024.
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Abstract An axial vane rotary engine (AVRE) is a novel type of rotary engines. The engine is a positive displacement mechanism that permits the four “stroke” action to occur in one revolution of the shaft with a minimum number of moving components in comparison to reciprocating engines. In this paper, a two-zone combustion model is developed for a spark ignition AVRE. The combustion chamber is divided into burned and unburned zones and differential equations are developed for the change in pressure and change in temperature in each zone. The modelling is based on equations for energy and mass conservation, equation of state, and burned mass fraction. The assumption is made that both zones are at the same pressure P, and the ignition temperature is the adiabatic flame temperature based on the mixture enthalpy at the onset of combustion. The developed code for engine simulation in MATLAB is applied to another engine and there is a good agreement between results of this code and results related to the engine chosen for validation, so the modelling is independent of configuration.
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Wang, Yang, Wuqiang Long, Jingchen Cui, Xin Wang, Hua Tian, and Xiangyu Meng. "Research on two-stroke compression release braking performance of a variable mode valve actuation system." International Journal of Engine Research 21, no. 9 (December 24, 2019): 1696–708. http://dx.doi.org/10.1177/1468087419894449.
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In order to enhance the braking safety and improve the fuel economy and emission of heavy-duty engines, a variable mode valve actuation system which can switch operation modes flexibly among four-stroke driving, two-stroke compression release braking, and cylinder deactivation modes on a four-stroke engine was developed in this article. The switching was controlled by the four-stroke driving module and the two-stroke braking module, both of which have two states: effective state and failure state. Besides, a full-cycle numerical model of a six-cylinder turbocharged engine was established for the performance analysis of two-stroke compression release braking mode. The orthogonal design method was introduced in the present study to obtain the optimum valve parameters which can result in high braking power and maintain the maximum cylinder pressure at a lower level at the same time. Then, the two-stroke compression release brake braking power with the optimum valve parameters was compared with four-stroke compression release braking power. Meanwhile, the two-stroke braking cam profile of the variable mode valve actuation system was designed according to the optimum valve parameters, and the two-stroke braking performance with the dynamic valve lift of the variable mode valve actuation system was validated by the numerical model including the hydraulic system. The results indicated that a higher engine speed leads to higher braking power at the same valve lift. Besides, two-stroke compression release brake braking power of the variable mode valve actuation system achieved 525.3 kW at 2600 r/min and 358.1 kW at 1900 r/min, 52.9% and 71.3% higher than four-stroke compression release braking power, respectively. Although the two-stroke compression release brake braking power with dynamic valve lift is slightly less than that with the optimum valve parameters, it is still much higher than that of the four-stroke compression release braking power. Therefore, it has a good application prospect for heavy-duty engines.
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Woodward, J. B. "Air-Standard Modelling for Closed-Cycle Diesel Engines." Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy 209, no. 2 (May 1995): 115–23. http://dx.doi.org/10.1243/pime_proc_1995_209_022_02.
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The author posits that a model constructed from ideal processes is the most desirable starting point for analysis of real power machinery, and then presents means of following this concept in the case of a closed-cycle diesel engine. The traditional air-standard limited-pressure cycle is found unsuitable for this application in that it offers only an unrealistic constant-volume cooling as the model for the processes that must occur between cylinder exhaust and cylinder intake. The present paper substitutes isentropic expansion, throttling and constant-pressure cooling as being suitable ideal models for the actual processes. Equations are presented and sample calculations are given for the cylinder-to-cylinder part of an ideal cycle representing a four-stroke naturally aspirated engine. Two alternatives are also discussed via examples: an engine with partial bypassing of untreated exhaust gas to the cylinder intake and a two-stroke engine with blower or compressor driven by an exhaust gas turbine. A closing example is given to demonstrate one way in which the analyses can be used to find the effect of external process states an engine-cycle output.
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Hooper, Peter R. "Investigation into a stepped-piston engine solution for automotive range-extender vehicles and hybrid electric vehicles to meet future green transportation objectives." Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 232, no. 3 (May 30, 2017): 305–17. http://dx.doi.org/10.1177/0954407017698304.
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Securing the objectives for future high-efficiency low-carbon-dioxide vehicles is a key target for automotive manufacturers. This paper considers a high-durability two-stroke cycle engine in terms of performance and computational modelling of the emissions characteristics for automotive range-extender or hybrid electric vehicle power plant application. The engine uses novel segregated pump charging via the application of stepped pistons, and a comparison of the engine characteristics is made with those of a comparable four-stroke cycle engine of similar expected power output (more than 60 kW/l). In the interests of cost minimisation, both engines are limited to parallel two-cylinder in-line configurations with the intention of still being able to achieve acceptably low noise, vibration and harshness characteristics. In order to achieve low engine exhaust emissions, computational modelling of direct injection is considered for the stepped-piston engine. A significant reduction in the nitrogen oxide emissions of between 31% and 55% is observed.
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Abramović, Luka, Dragan Martinović, and Davor Lenac. "Analysis of variable Inlet Valve Control in two-stage turbocharged marine four-stroke Diesel engines – Miller cycle." Pomorstvo 31, no. 1 (June 29, 2017): 67–73. http://dx.doi.org/10.31217/p.31.1.9.
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With the ever so imminent threat of climate change caused by man-made pollution, IMO introduces a new piece of legislature: IMO Annex 6 Tier III regarding air pollution. To meet new standards of exhaust air content, engineers are scrambling to find new and efficient ways to keep the shipping industry going. With the dawn of two-stage turbocharging developing high values of inlet air pressure in combination with early IVC using variable valve actuation depending on the engine load, the regulations are met. In this study the effectiveness of the previously mentioned concepts are put to the test against the conventional Diesel cycle used on board most vessels today. A detailed comparison of the two is conducted followed by a thorough analysis and argumentation.
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Pla, Benjamin, Joaquin De la Morena, Pau Bares, and Irina Jiménez. "Cycle-to-cycle combustion variability modelling in spark ignited engines for control purposes." International Journal of Engine Research 21, no. 8 (November 1, 2019): 1398–411. http://dx.doi.org/10.1177/1468087419885754.
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A control-oriented model of spark ignition combustion is presented. The model makes use of avaliable signals, such as spark advance, air mass, intake pressure, and lambda, to characterize not only the average combustion evolution but also the cycle-to-cycle variability. The conventional turbulent flame propagation model with two states, namely entrained mass and burnt mass, is improved by look-up tables at some parameters, and the cycle-to-cycle variability is estimated by propagation of an exogenous noise with a normal probabilistic distribution at the turbulent and laminar flame speed, which intends to simulate the unknowns at turbulent flow, temperature distribution, or initial kernel distribution. The model is able to estimate which is the expected variability during the combustion evolution and might be used online for characterizing the time response of closed-loop control actions or it can be used offline to improve the control strategies without large experimental test campaigns. Experimental data from a four-stroke commercial engine was used for calibration and validation purposes, demonstrating the capabilities of the model in steady and transient conditions.
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Korakianitis, T., L. Meyer, M. Boruta, and H. E. McCormick. "Introduction and Performance Prediction of a Nutating-Disk Engine." Journal of Engineering for Gas Turbines and Power 126, no. 2 (April 1, 2004): 294–99. http://dx.doi.org/10.1115/1.1635394.
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A new type of internal combustion engine and its thermodynamic cycle are introduced. The core of the engine is a nutating nonrotating disk, with the center of its hub mounted in the middle of a Z-shaped shaft. The two ends of the shaft rotate, while the disk nutates. The motion of the disk circumference prescribes a portion of a sphere. A portion of the area of the disk is used for intake and compression, a portion is used to seal against a center casing, and the remaining portion is used for expansion and exhaust. The compressed air is admitted to an external accumulator, and then into an external combustion chamber before it is admitted to the power side of the disk. The accumulator and combustion chamber are kept at constant pressures. The engine has a few analogies with piston-engine operation, but like a gas turbine it has dedicated spaces and devices for compression, burning, and expansion. The thermal efficiency is similar to that of comparably sized simple-cycle gas turbines and piston engines. For the same engine volume and weight, this engine produces less specific power than a simple-cycle gas turbine, but approximately twice the power of a two-stroke engine and four times the power of a four-stroke engine. The engine has advantages in the 10 kW to 200 kW power range. This paper introduces the geometry and thermodynamic model for the engine, presents typical performance curves, and discusses the relative advantages of this engine over its competitors.
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Olsen, D. B., J. C. Holden, G. C. Hutcherson, and B. D. Willson. "Formaldehyde Characterization Utilizing In-Cylinder Sampling in a Large Bore Natural Gas Engine." Journal of Engineering for Gas Turbines and Power 123, no. 3 (December 7, 2000): 669–76. http://dx.doi.org/10.1115/1.1363601.
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This research addresses the growing need to better understand the mechanisms through which engine-out formaldehyde is formed in two-stroke cycle large bore natural gas engines. The investigation is performed using a number of different in-cylinder sampling techniques implemented on a Cooper-Bessemer GMV-4TF four-cylinder two-stroke cycle large bore natural gas engine with a 36-cm (14-in.) bore and a 36-cm (14-in.) stroke. The development and application of various in-cylinder sampling techniques is described. Three different types of valves are utilized, (1) a large sample valve for extracting a significant fraction of the cylinder mass, (2) a fast sample valve for crank angle resolution, and (3) check valves. Formaldehyde in-cylinder sampling data are presented that show formaldehyde mole fractions at different times during the engine cycle and at different locations in the engine cylinder. The test results indicate that the latter part of the expansion process is a critical time for engine-out formaldehyde formation. The data show that significant levels of formaldehyde form during piston and end-gas compression. Additionally, formaldehyde is measured during the combustion process at mole fractions five to ten times higher than engine-out formaldehyde mole fractions. Formaldehyde is nearly completely destroyed during the final part of the combustion process. The test results provide insights that advance the current understanding and help direct future work on formaldehyde formation.
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Vera-García, Francisco, José Antonio Pagán Rubio, José Hernández Grau, and Daniel Albaladejo Hernández. "Improvements of a Failure Database for Marine Diesel Engines Using the RCM and Simulations." Energies 13, no. 1 (December 24, 2019): 104. http://dx.doi.org/10.3390/en13010104.
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Diesel engines are widely used in marine transportation as a direct connection to the propeller and as electrical principal or auxiliary generator sets. The engine is the most critical piece of equipment on a vessel platform; therefore, the engine’s reliability is paramount in order to optimize safety, life cycle costs, and energy of the boat, and hence, vessel availability. In this paper, the improvements of a failure database used for a four-stroke high-speed marine diesel engine are discussed. This type of engine is normally used in military and civil vessels as the main engine of small patrols and yachts and as an auxiliary generator set (GENSET) for larger vessels. This database was assembled by considering “failure modes, effects, and criticality analysis (FMECA),” as well as an analysis of the symptoms obtained in an engine failure simulator. The FMECA was performed following the methodology of reliability-centered maintenance (RCM), while the engine response against failures was obtained from a failure simulator based on a thermodynamic one-dimensional model created by the authors, which was adjusted and validated with experimental data. The novelty of this work is the methodology applied, which combines expert knowledge of the asset, the RCM methodology, and the failure simulation to obtain an accurate and reliable database for the prediction of failures, which serves as a key element of a diesel engine failure diagnosis system.
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Omocea, Ion. "Analysis of Compression Ignition Engine Cycle Based on Irreversible Thermodynamics." Advanced Materials Research 837 (November 2013): 446–51. http://dx.doi.org/10.4028/www.scientific.net/amr.837.446.
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We use a model that is based on the cycle behavior inlet pressure variation. This analysis revealed the two main regimes of operation marine propulsion engines. Pressure drop in the suction process can be seen from two points of view: this pressure drop is an active dissipation and at the same time is a passive dissipation, contributing to the deterioration of cycle infrastructure. Interference of the two effects is reflected by the appearance of a ψaopt=0,3...0,35, for which indicated power Pi becomes maximum in terms of given geometric and gazodynamic configurations. Respectively for a weighting of conductance gazodynamic imposed. When fuel flow is imposed, the analysis revealed that the share of shall be amended to variation of ψa, which involves the geometric and gazodynamic configuration variable. In this numerical analysis showed the existence of ψaopt=0,1...0,15, for which indicated efficiency ηi is maximum. These findings are the basis for the complex optimization cycle program for four-stroke compression ignition engine.
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Prabhakar, S., V. N. Banugopan, K. Annamalai, P. Sentilkumar, G. Devaradjane, and S. Jayaraj. "Influence of injection timing on the performance, emissions, combustion analysis and sound characteristics of Nerium biodiesel operated single cylinder four stroke cycle direct injection diesel engine." Material Science Research India 7, no. 1 (June 25, 2010): 201–7. http://dx.doi.org/10.13005/msri/070125.
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The automobile sector which is growing day to day consumes the fossil fuel more than its growth. So there is a demand for exploring new sources of fuels for existing engines. This led to the growth in bio diesels which is an alternate fuel. An alternative fuel must be technically feasible, economically competitive, environmentally acceptable, and readily available. In this project esterified Nerium oil is used as an alternate fuel. A single cylinder stationary kirloskar engine is used to compare the performance and emission characteristics between pure diesel and Nerium blends. In this project selection of suitable nerium blend and selection of optimized injection timing for the blend is done. The Nerium oil blends are in percentage of 20%, 40%, 60%, 80%, and 100% of Nerium oil to 80%, 60%, 40%, 20% & 0% of diesel. From this project it is concluded that among all nerium and diesel blends 20% of nerium and 80% of diesel blend at 30º BTDC gives better performance nearing the diesel. When comparing the emission characteristics HC, CO is reduced when compared to diesel, however NOx emission is slightly increased when compared to diesel. Hence Nerium blend can be used in existing diesel engines with minimum modification in the engine. It also describes the usage of non-edible oil to a greater extent.
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Septivani, Nike, and Byan Wahyu Riyandwita. "Spark ignition engine modeling for in-cylinder pressure and temperature prediction using simulink." MATEC Web of Conferences 204 (2018): 04001. http://dx.doi.org/10.1051/matecconf/201820404001.
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Mathematical model for four-stroke gasoline engines based on a cylinder-by-cylinder engine modeling method that incorporates physical formulas such as engine geometry and empirical formulas such as combustion duration are applied in this study. In-cylinder pressure and temperature can be calculated for gasoline four-cycle engine. Modeling is done by treating each step in the cylinder as a volume control, solving the conservation equations of energy with submodules for combustion, heat transfer and dynamic analysis. Calculations in cycles are performed at each crank angle, so that the correct angle of ignition, variations in velocity, amount of intake mass and fuel burning speed can be predicted. Adjustment for the combustion parameter such as burn duration and form factor of the Wiebe function to increase the model accuracy was performed. It is shown that the optimization of the Wiebe function parameters able to improve the sum squared error of the engine pressure estimation by 58.17% compared to the result from generalized parameter functions, and the parameter of form factor and burn duration are influential by around twice of (1.86 and 2.55 times, respectively) the efficiency factor.
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MONIETA, Jan. "Modelling of the fuel injection of medium speed marine diesel engines." Combustion Engines 170, no. 3 (August 1, 2017): 139–46. http://dx.doi.org/10.19206/ce-2017-324.
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The article presents the stages of fuel injection modeling of the four-stroke marine diesel engines as a set of functional blocks the of the fuel waves flow. The elaborated model includes the values of changing pressures in the combustion chamber and the course of changes of the pressure in spaces of the injection pump, injection pipe and the injector. Linear and local losses, as well as the conditions for the functioning were taken into account in stages of the fuel flow. The influence of different values of the engine load on the pressure course of the in individual spaces of injection apparatus and in the engine cylinder during the working cycle depending on the crank angle of rotation of the crankshaft have been simulated. The mathematical relationships were selected and the structural and experimental data are used, allowing the calculation of the parameters of interest for the simulated process.
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GNANAM, Gnanaprakash, Dale HAGGITH, and Andrzej SOBIESIAK. "A novel in-cylinder fuel reformation approach to control HCCI engine combustion on-set." Combustion Engines 138, no. 3 (July 1, 2009): 37–48. http://dx.doi.org/10.19206/ce-117179.
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Homogeneous Charge Compression Ignition (HCCI) engines have the potential to deliver high thermal efficiencies (when compared to spark ignition engines) coupled with ultra-low NOx emissions and Particulate Matter (PM) for partial-load operating regions. However, the inherent absence of Start of Combustion (SOC) or combustion on-set control has been a major obstacle for implementing this technology into production engines. In the present work, a new in-cylinder reformation strategy to control the on-set of combustion has been incorporated into a HCCI engine fuelled with lean ethanol/air mixtures. The objective of the in-cylinder reformation process is to generate hydrogen enriched gas (which includes other intermediate species) from ethanol reformation, which is then used to control the subsequent HCCI cycle combustion on-set. The experimental engine used for the study is a four-stroke, three cylinder In-Direct Injection (IDI) type compression ignition engine which was converted to single cylinder operation for HCCI combustion. A proto-type reformation chamber has been designed and fabricated with direct injection capabilities to examine the proposed in-cylinder reformation process. In order to clarify the effects of reformation products on HCCI combustion on-set, experiments were conducted with constant engine speed, initial charge temperature, and engine coolant temperature. The engine performance was evaluated based on cycle-resolved in-cylinder pressure measurements and regulated engine-out emissions. The experimental results demonstrate that the proposed in-cylinder reformation strategy is an effective method for controlling HCCI combustion on-set (SOC) and reduces the regulated engine-out emissions. Furthermore, the experimental results indicate that there is an optimal in-cylinder reformation fuelling percentage which will have a positive impact on regular HCCI combustion at given operating conditions.
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Farzaneh-Gord, Mahmood, and Hamid Hajializadeh. "Combined Simulation of Spark Ignition Internal Combustion Engines and Heat Conduction within Piston." Journal of Algorithms & Computational Technology 3, no. 3 (September 2009): 363–78. http://dx.doi.org/10.1260/174830108788251755.
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A combined thermodynamic simulation and transient conduction heat transfer through piston has been carried out in this study. In thermodynamic simulation, A computer programme has been developed to study the full operation cycle of a four stroke internal combustion engine. The simulation used to calculate the pressure and temperature field existing in realistic engine combustion chambers for various engine parameters. The one dimensional conduction heat transfer equation has been solved numerically. The results show a good agreement with previous studies where applicable.
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Omanovic, Andyn, Norbert Zsiga, Patrik Soltic, and Christopher Onder. "Increased Internal Combustion Engine Efficiency with Optimized Valve Timings in Extended Stroke Operation." Energies 14, no. 10 (May 11, 2021): 2750. http://dx.doi.org/10.3390/en14102750.
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Spark-ignited internal combustion engines are known to exhibit a decreased brake efficiency in part-load operation. Similarly to cylinder deactivation, the x-stroke operation presented in this paper is an adjustable form of skip-cycle operation. It is an effective measure to increase the efficiency of an internal combustion engine, which has to be equipped with a variable valve train to enable this feature. This paper presents an optimization procedure for the exhaust valve timings applicable to any valid stroke operation number greater than four. In the first part, the gas spring operation, during which all gas exchange valves are closed, is explained, as well as how it affects the indicated efficiency and the blow-by mass flow. In the second part, a simulation model with variable valve timings, parameterized with measurement data obtained on the engine test, is used to find the optimal valve timings. We show that in 12-stroke operation and with a cylinder load of 5 Nm, an indicated efficiency of 34.3% is achieved. Preloading the gas spring with residual gas prevents oil suction and thus helps to reduce hydrocarbon emissions. Measurements of load variations in 4-, 8-, and 12-stroke operations show that by applying an x-stroke operation, the indicated efficiency remains high and the center of combustion remains optimal in the range of significantly lower torque outputs.
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Tong, Qiang, Hui Xie, Kang Song, and Dong Zou. "A Control-Oriented Engine Torque Online Estimation Approach for Gasoline Engines Based on In-Cycle Crankshaft Speed Dynamics." Energies 12, no. 24 (December 9, 2019): 4683. http://dx.doi.org/10.3390/en12244683.
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Engine brake torque is a key feedback variable for the optimal torque split control of an engine–motor hybrid powertrain system. Due to the limitations in available sensors, however, engine torque is difficult to measure directly. For torque estimation, the unknown external load torque and the overlap of the expansion stroke between cylinders introduce a great disturbance to engine speed dynamics. This makes the conventional cycle average engine speed-based estimation approach unusable. In this article, an in-cycle crankshaft speed-based indicated torque estimation approach is proposed for a four-cylinder engine. First, a unique crankshaft angle window is selected for load torque estimation without the influence of combustion torque. Then, an in-cycle angle-domain crankshaft speed dynamic model is developed for engine indicated torque estimation. To account for the effects of model inaccuracy and unknown external disturbances, a “total disturbance” term is introduced. The total disturbance is then estimated by an adaptive observer using the engine’s historical operating data. Finally, a real-time correction method for the friction torque is proposed in the fuel cut-off scenario. Combining the aforementioned torque estimators, the brake torque can be obtained. The proposed algorithm is implemented in an in-house developed multi-core engine control unit (ECU). Experimental validation results on an engine test bench show that the algorithm’s execution time is about 3.2 ms, and the estimation error of the brake torque is within 5%. Therefore, the proposed method is a promising way to accurately estimate engine torque in real-time.
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OYAMADA, Tetsuya, Yutaro WAKURI, Yoshinori HIRAYAMA, and Hiroshi IKUTA. "Mass Estimation and Evaluation Simulating Method for Optimum Planning on Four-Stroke Cycle, Medium Speed, V-Type Diesel Engines." Transactions of the Japan Society of Mechanical Engineers Series B 68, no. 668 (2002): 1308–13. http://dx.doi.org/10.1299/kikaib.68.1308.
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Lebedevas, Sergejus, and Tomas Čepaitis. "Research of Organic Rankine Cycle Energy Characteristics at Operating Modes of Marine Diesel Engine." Journal of Marine Science and Engineering 9, no. 10 (September 23, 2021): 1049. http://dx.doi.org/10.3390/jmse9101049.
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The publication examines one of the most effective ways to decarbonize marine transport, specifically the secondary heat sources utilization in the cogeneration cycle of the main engines. The research focuses on the optimization of Organic Rankine Cycle (ORC) performance parameters by combining them with the exhaust energy potential of a medium speed four-stroke main diesel engine in ISO8178 (E3) load cycle modes. Significant advantages were not found between the evaluated Wet-, Isentropic-, and Dry-type liquids (R134a, R141b, R142b, R245fa, Isopentane) in terms of ORC energy performance with a 10% difference. The use of a variable geometry turbogenerator turbine with Dry-type (R134a) working fluid is characterized by the highest ORC energy efficiency up to 15% and an increase in power plant (including turbogenerator generated mechanical) by 6.2%. For a fixed geometry turbine, a rational control strategy of the working fluid flow (Gd.sk − πT) is determined by the priorities of the power plant in certain load modes. The influence of the overboard water temperature on the ORC energy indicators does not exceed ±1%; however, it influences the thermodynamic saturation parameters of the working fluid condensation and, in connection with that, the fluid selection.
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OYAMADA, Tetsuya, Yutaro WAKURI, Yoshinori HIRAYAMA, and Hiroshi IKUTA. "617 Mass Estimation and Evaluation Simulating Method for Optimum Planning on Four-Stroke Cycle, Medium Speed, V-Type Diesel Engines." Proceedings of Conference of Kyushu Branch 2001 (2001): 223–24. http://dx.doi.org/10.1299/jsmekyushu.2001.223.
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Liu, Ruichao, Xianghui Meng, and Yi Cui. "Influence of numerous start-ups and stops on tribological performance evolution of engine main bearings." International Journal of Engine Research 21, no. 8 (October 31, 2018): 1362–80. http://dx.doi.org/10.1177/1468087418810094.
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For main bearings of internal combustion engines, most of the wear occurs during the start-ups and stops. The popularity of the start–stop system in automobile engines, which is used to save fuel consumption during idling stage, makes the working condition of main bearings severer because more frequent starts and stops will be generated. Changes in the bearing surface caused by wear will directly affect the bearing’s working performance. So in this study a transient mixed lubrication model and a wear model are coupled to analyze the influence of numerous start-ups and stops on the tribological performance evolution of engine main bearings. Starved lubrication of bearings before the oil supply is considered. The wear process is studied on the scale of surface topography and geometry. A main bearing in a four-stroke four-cylinder gasoline engine is studied under engine start–stop cycle conditions. The effects of temperature and lubricant grade on the transient tribodynamic behavior during the start-ups and stops are first investigated. Then the evolutions of surface characteristics and tribological performance of main bearings after numerous engine start-ups and stops are simulated. Results show that the temperature and lubricant grade can significantly affect the friction and wear of bearings. Hot start–stop condition leads to more serious asperity contact friction in the early stage of start-up, while cold start–stop condition generates more friction loss. The wear process of bearing surface is faster when applying oil with lower viscosity. And the impacts of engine start-ups and stops on bearing working performance are mainly seen in contact friction.
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Wang, Xinyan, Jun Ma, and Hua Zhao. "Analysis of mixture formation process in a two-stroke boosted uniflow scavenged direct injection gasoline engine." International Journal of Engine Research 19, no. 9 (October 17, 2017): 927–40. http://dx.doi.org/10.1177/1468087417736451.
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The two-stroke engine has the great potential for aggressive engine downsizing and downspeeding because of its double firing frequency. For a given torque, it is characterized with a lower mean effective pressure and lower peak in-cylinder pressure than a four-stroke counterpart. In order to explore the potential of two-stroke cycle while avoiding the drawbacks of conventional ported two-stroke engines, a novel two-stroke boosted uniflow scavenged direct injection gasoline engine was proposed and designed. In order to achieve the stable lean-burn combustion in the boosted uniflow scavenged direct injection gasoline engine, the mixture preparation, especially the fuel stratification around the spark plug, should be accurately controlled. As the angled intake scavenge ports produce strong swirl flow motion and complex transfer between the swirl and tumble flows in the two-stroke boosted uniflow scavenged direct injection gasoline engine, the interaction between the in-cylinder flow motions and the direct injection and its impact on the charge preparation in the boosted uniflow scavenged direct injection gasoline engine are investigated in this study by three-dimensional computational fluid dynamics simulations. Both the single injection and split injections are applied and their impact on the mixture formation process is investigated. The start of injection timing and split injection ratio are adjusted accordingly to optimize the charge preparation for each injection strategy. The results show that the strong interaction between the fuel injection and in-cylinder flow motions dominates the mixture preparation in the boosted uniflow scavenged direct injection gasoline engine. Compared to the single injection, the split injection shows less impact on the large-scale flow motions. Good fuel stratification around the spark plug was obtained by the late start of injection timings at 300 °CA/320 °CA with an equal amount in each injection. However, when a higher tumble flow motion is produced by the eight scavenge ports’ design, a better fuel charge stratification can be achieved with the later single injection at start of injection of 320 °CA.
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Olsen, D. B., G. C. Hutcherson, B. D. Willson, and C. E. Mitchell. "Development of the Tracer Gas Method for Large Bore Natural Gas Engines—Part II: Measurement of Scavenging Parameters." Journal of Engineering for Gas Turbines and Power 124, no. 3 (June 19, 2002): 686–94. http://dx.doi.org/10.1115/1.1454117.
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In this work the tracer gas method using nitrous oxide as the tracer gas is implemented on a stationary two-stroke cycle, four-cylinder, fuel-injected large-bore natural gas engine. The engine is manufactured by Cooper-Bessemer, model number GMV-4TF. It is representative of the large bore natural gas stationary engine fleet currently in use by the natural gas industry for natural gas compression and power generation. Trapping efficiency measurements are carried out with the tracer gas method at various engine operating conditions, and used to evaluate the scavenging efficiency and trapped A/F ratio. Scavenging efficiency directly affects engine power and trapped A/F ratio has a dramatic impact on pollutant emissions. Engine operating conditions are altered through variations in boost pressure, speed, back pressure, and intake port restriction.
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C, Ramesh, Murugesan A, and Vijayakumar C. "Reducing the Environmental Pollution from Diesel Engine Fuelled with Eco- Friendly Biodiesel Blends." Bulletin of Scientific Research 1, no. 2 (November 16, 2019): 35–44. http://dx.doi.org/10.34256/bsr1925.
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Diesel engines are widely used for their low fuel consumption and better efficiency. Fuel conservation, efficiency and emission control are always the investigation points in the view of researchers in developing energy system. India to search for a suitable environmental friendly alternative to diesel fuel. The regulated emissions from diesel engines are carbon monoxide (CO), Hydrocarbons (HC), NOx and Particulate matter. It creates cancer, lungs problems, headaches and physical and mental problems of human. This paper focuses on the substitution of fossil fuel diesel with renewable alternatives fuel such as Biodiesel. Biodiesel is much clear than fossil diesel fuel and it can be used in any diesel engine without major modification. The experiment was conducted in a single-cylinder four-stroke water-cooled 3.4 kW direct injection compression ignition engine fueled with non-edible Pungamia oil biodiesel blends. The experimental results proved that up to 40% of Pungamia oil biodiesel blends give better results compared to diesel fuel. The AVL 444 di-gas analyzer and AVL 437 smoke meter are used to measure the exhaust emissions from the engine. The observation of results, non-edible Pongamia biodiesel blended fuels brake thermal efficiency (3.59%) is improved and harmful emissions like CO, unburned HC, CO2, Particulate matter, soot particles, NOx and smoke levels are 29.67%, 26.65%, 33.47%, 39.57%, +/- 3.5 and 41.03% is decreased respectively compared to the diesel fuel. This is due to biodiesel contains the inbuilt oxygen content, ignition quality, carbon burns fully, less sulphur content, no aromatics, complete CO2 cycle.
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Andreev, Mikhail, Yuriy Zhuravlev, Yuriy Lukyanov, and Leonid Perminov. "Autonomous Power Station Based on Rotary-Vane Engine with an External Supply of Heat." Environment. Technology. Resources. Proceedings of the International Scientific and Practical Conference 2 (August 8, 2015): 97. http://dx.doi.org/10.17770/etr2013vol2.842.
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Rotary-vane engine (RVE) with an external supply of heat is an aggregate consisting of two modules with a common output shaft, the heating device (heater) of working medium and the cooling device (cooler) of working medium, which connected with inlet and outlet ports of modules by system of pipeworks. Each module has two rotors with two vanes on each. Between the corresponding plane surfaces of the four vanes four working volumes are formed wherein thermodynamic cycle steps: ingress, compressing, heat intake, expansion stroke, discharge, outward heat transmission are going simultaneously. The angular displacement of modules relative to one another occurs pumping the working medium through the heater and cooler, which allows the conversion of thermal energy into mechanical work. Design features of the RVE with an external supply of heat allows create a closed gas-vapor cycle. The main specified advantages of the RVE with an external supply of heat are: fewer noxious emissions, multifuel capability, high motor potential (service life). Different problems of creation external combustion engines such as structural complexity of construction units, absence of adequate mathematical model of designed RVE with an external supply of heat are also pointed. The construction of the RVE with an external supply of heat developed in Pskov Polytechnic Institute (now the Pskov State University), the operation concept of the engine, the physical processes in the chamber modules RVE with an external supply of heat during each step and the mathematical model describing the physical processes proceeding in chamber RVE with an external supply of heat modules are considered.
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Shi, Yan, and Si Qin Chang. "Research on Design and Testing of a Novel Power Source for Hybrid Vehicles." Applied Mechanics and Materials 29-32 (August 2010): 2285–89. http://dx.doi.org/10.4028/www.scientific.net/amm.29-32.2285.
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In auto industry extensive use of traditional IC engines and fossil fuel as power source has lead to serious environmental problems and social issues. Development of hybrid vehicles is a hopeful technology to solve above problems. As a vital part of IC engine-electric hybrid vehicles, power source should generate electricity efficiently. Supported by National High-tech R&D Program (863 Program) a novel Internal Combustion Linear-Generator Integrated Power System (ICLG) is researched in this paper. ICLG mainly consists of four-stroke free-piston engine, linear motor, reversible electrical energy storage device, and control unit and has the potential to convert the chemical energy of fuel to electrical energy efficiently. Achievements for improving efficiency, such as minimizing the energy transmission and conversion link, movement control of piston by adjusting electromagnetic force, optimization of thermodynamic cycle, and sub-cylinder or sub-cylinders mode, are analyzed and validated by testing. Testing results show that the generating efficiency is about 32%, which can be improved by further study. ICLG is hopeful to be the new generation power source of hybrid vehicles which has the character of power saving and environmental protecting.
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Liu, Haifeng, Xichang Wang, Diping Zhang, Fang Dong, Xinlu Liu, Yong Yang, Haozhong Huang, Yang Wang, Qianlong Wang, and Zunqing Zheng. "Investigation on Blending Effects of Gasoline Fuel with N-Butanol, DMF, and Ethanol on the Fuel Consumption and Harmful Emissions in a GDI Vehicle." Energies 12, no. 10 (May 15, 2019): 1845. http://dx.doi.org/10.3390/en12101845.
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The effects of three kinds of oxygenated fuel blends—i.e., ethanol-gasoline, n-butanol-gasoline, and 2,5-dimethylfuran (DMF)-gasoline-on fuel consumption, emissions, and acceleration performance were investigated in a passenger car with a chassis dynamometer. The engine mounted in the vehicle was a four-cylinder, four-stroke, turbocharging gasoline direct injection (GDI) engine with a displacement of 1.395 L. The test fuels include ethanol-gasoline, n-butanol-gasoline, and DMF-gasoline with four blending ratios of 20%, 50%, 75%, and 100%, and pure gasoline was also tested for comparison. The original contribution of this article is to systemically study the steady-state, transient-state, cold-start, and acceleration performance of the tested fuels under a wide range of blending ratios, especially at high blending ratios. It provides new insight and knowledge of the emission alleviation technique in terms of tailoring the biofuels in GDI turbocharged engines. The results of our works showed that operation with ethanol–gasoline, n-butanol–gasoline, and DMF–gasoline at high blending ratios could be realized in the GDI vehicle without any modification to its engine and the control system at the steady state. At steady-state operation, as compared with pure gasoline, the results indicated that blending n-butanol could reduce CO2, CO, total hydrocarbon (THC), and NOX emissions, which were also decreased by employing a higher blending ratio of n-butanol. However, a high fraction of n-butanol increased the volumetric fuel consumption, and so did the DMF–gasoline and ethanol–gasoline blends. A large fraction of DMF reduced THC emissions, but increased CO2 and NOX emissions. Blending n-butanol can improve the equivalent fuel consumption. Moreover, the particle number (PN) emissions were significantly decreased when using the high blending ratios of the three kinds of oxygenated fuels. According to the results of the New European Drive Cycle (NEDC) cycle, blending 20% of n-butanol with gasoline decreased CO2 emissions by 5.7% compared with pure gasoline and simultaneously reduced CO, THC, NOX emissions, while blending ethanol only reduced NOX emissions. PN and particulate matter (PM) emissions decreased significantly in all stages of the NEDC cycle with the oxygenated fuel blends; the highest reduction ratio in PN was 72.87% upon blending 20% ethanol at the NEDC cycle. The high proportion of n-butanol and DMF improved the acceleration performance of the vehicle.
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Kouremenos, D. A., C. D. Rakopoulos, and D. Hountalas. "Thermodynamic Analysis of Indirect Injection Diesel Engines by Two-Zone Modeling of Combustion." Journal of Engineering for Gas Turbines and Power 112, no. 1 (January 1, 1990): 138–49. http://dx.doi.org/10.1115/1.2906468.
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This work presents a thermodynamic analysis of a naturally aspirated, four-stroke, diesel engine with a swirl prechamber, under firing conditions during the open and closed part of the cycle. For calculating the heat exchange between gas and walls in both the main chamber and (swirl) prechamber, the relevant characteristic velocities and lengths are calculated by setting up a zero-dimensional energy cascade turbulence model. One-dimensional, quasi-steady, compressible flow with heat transfer inside the throat passageway connecting the two chambers is used. Combustion in both the main chamber and the swirl prechamber is attacked by proposing a two-zone combustion model, and following the movement of the spray plume inside an air solid body rotation environment in the prechamber and its later progression into the main chamber through the connecting throat. To validate the analysis, an extensive experimental investigation is undertaken at the laboratory of the authors on a flexible Ricardo, single-cylinder, swirl chamber diesel engine, and evaluating its performance in a wide range of operating conditions. The experimental results are found to be in good agreement with the theoretical results obtained from the computer program implementing the analysis.
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Putintsev, S. V., S. S. Strelnikova, and S. A. Anikin. "Calculation and identification of the coordinate of oil jet ejection from the gap of a rotating connecting rod bearing." Traktory i sel'hozmashiny 1, no. 5 (2020): 25–32. http://dx.doi.org/10.31992/0321-4443-2020-5-25-32.
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The development of a modern high-speed, energy-efficient and reliable diesel engine requires high-quality lubrication of all friction parts in general and parts of the cylinder-piston group (CPG) in particular. The relevance of this research is due to the insufficient study of the process of oil jet supply of CPG parts, implemented in combined lubrication systems of modern high-speed four-stroke engines and significantly affecting the processes of friction, wear and scuffing of parts of this group. The analysis of previously performed works in this area has shown the feasibility of not only setting up an experiment, but also using computational modeling in order to increase the informa-tivity of the results obtained. The aim of the study was to determine the coordinates of the point of ejection of the oil jet from the gap of the rotating connecting rod bearing. According to the accepted working hypothesis, the point of ejection of the oil jet was the geometric place of the maximum gap in the connecting rod bearing. To calculate the angular coordinate of this point, authors used the method of composing and solving equations of plane motion of a solid body. As a result of the re-search, an analytical expression of the desired coordinate was obtained and its value was calculated during the working cycle for the conditions of the nominal operating mode of the research object – a high-speed universal air-cooled diesel engine 1CH 8.5/8.0 (TMZ-450D). Ensuring the reliability and increasing the accuracy of the results of the study is confirmed by comparison with the calculated data obtained by the method of classical dynamics of piston engines. The array of calculated values of the coordinate of the oil jet ejection point from the gap of the rotating connecting rod bearing of the diesel engine, defined in this paper, will be used for debugging the developed tool for calculating modeling of the oil jet feed process and subsequent optimization of the conditions of lubrication, friction and wear of CPG parts on this basis.
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OYAMADA, Tetsuya, Yutaro WAKURI, Yoshinori HIRAYAMA, and Hiroshi IKUTA. "Analyses of the Influence Degree of Principal Particulars on the Engine-Mass and Simplified Engine-Mass Estimation Method for Optimum Planning on the Four-Stroke Cycle, Medium Speed, V-Type Diesel Engines (Supplemental Report)." Transactions of the Japan Society of Mechanical Engineers Series B 71, no. 701 (2005): 365–72. http://dx.doi.org/10.1299/kikaib.71.365.
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Ting-Ting Zhu. "Explosive Results: Simulating a Four-Stroke Engine Cycle." IEEE Computational Science and Engineering 2, no. 3 (1995): 4. http://dx.doi.org/10.1109/mcse.1995.414868.
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