Showing papers on "Four-stroke engine published in 2011"

Piston for an internal combustion engine and method for its production

Abstract: A piston for an internal combustion engine has a piston head, a piston skirt, and a circumferential recess configured between the piston head and the piston skirt. The piston has a piston base body and a piston ring element. The piston base body has a crown region of a combustion bowl and the piston skirt. The piston ring element has a piston crown, a wall region of the combustion bowl, a circumferential top land, and a circumferential ring belt with ring grooves. The piston ring element has a circumferential cooling channel between the wall region of the combustion bowl and the ring belt, closed with a closure element. The piston base body and the piston ring element have a circumferential joining seam in the region of the combustion bowl, by way of which seam they are non-releasably connected with one another.

Use of palm oil biodiesel blends as a fuel for compression ignition engine.

Abstract: Problem statement: The increasing awareness of the environmental haza rds and the alarming levels of air pollution have led to more r estrictive regulations on engines emission control in recent years. Approach: The dwindling resources and rising cost of crude o il had resulted in an intensified search for alternate fuels. In the pres ent study biodiesel (palm oil methyl ester) blends with diesel was investigated in a direct injection stati onary diesel engine. The stationary engine test bed used consists of a single-cylinder four stroke dies el engine, eddy current dynamometer with computer control data acquisition system and exhaust emissio ns analyzer. Results: Engine tests were conducted at constant speed using neat diesel fuel and variou s proportions of biodiesel blends. The exhaust emissions such as CO, HC and NOx were measured using exhaust gas analyzer. Performance characteristics like brake thermal efficiency and s pecific fuel consumption were recorded. The differences in the measured emissions and performance of the biodiesel-diesel fuel blends from the baseline operation of the engine, i.e., when workin g with neat diesel fuel were determined and compared. Conclusion: It is concluded that the lower blends of biodiesel increased the brake thermal efficiency and reduced the fuel consumption. Biodie sel blends produces lower engine emissions than diesel. From the result, it has been established th at 20-40% of palm oil biodiesel can be use as a substitute for diesel without any engine modificati ons.

Optimization of injection pressure for a compression ignition engine with cotton seed oil as an alternate fuel

Abstract: The major problem with the direct use of vegetable oils as fuel into CI engines is their higher viscosity. It interferes the fuel injection and atomization and contributes to incomplete combustion, nozzle clogging, excessive engine deposits, ring sticking, producing thick smoke, etc. The problem of higher viscosity of vegetable oils can be overcome to a greater extent by various techniques, such as heating of fuel lines, trans-esterification, modification of injection system, etc. In the present investigation, short term tests were conducted with the use of untreated cotton seed oil in a single cylinder, four stroke, and direct injection diesel engine. Tests were conducted with cotton seed oil and diesel. To improve the combustion characteristics of cotton seed oil in an unmodified engine, effect of increase in injection pressure was studied. The injection pressure was increased from 180 bar to 240 bar (in steps of 15 bar). The investigation revealed that the optimum pressure for cottonseed oil as 210 bar and comparison of the performance of the engine was studied in terms of brake specific fuel consumption, brake thermal efficiency, indicated thermal efficiency, mechanical efficiency and exhaust emissions. International Journal of Engineering, Science and Technology, Vol. 2, No. 6, 2010, pp. 142-149

Experimental Investigation of Coconut and Palm Oils as Lubricants in Four-Stroke Engine

Abstract: In the present work the evaluation of coconut and palm oil as lubricants in four-stroke engine was carried out and the performance was compared with commercially available engine oil. The tribological properties of oil samples collected from the engine at regular interval were evaluated by means of four ball tester. The emissions from engine were monitored by using exhaust gas analyzer. It was observed that antiwear properties of fresh vegetable base oils and engine oil were comparable at ambient conditions. The observed deviation with usage was linked to the oxidation and the absence of additives in vegetable oil. The increased wear with commercial engine oil was due to depletion of additives. Increased fuel efficiency and reduction in the concentration of oxides of carbon and nitrogen in the emission observed with vegetable oil based lubricant was linked to its high flash point.

Dynamic analysis of piston secondary motion in an internal combustion engine under non-lubricated and fully flooded lubricated conditions

Abstract: A dynamic model is presented for the internal combustion engine in which the primary motion of the pistons is determined by the gas pressure in the cylinders rather than by an assumed steady rotation of the crank, and the secondary motion of the pistons is determined by the interaction of the pistons with the cylinder walls under non-lubricated and fully flooded lubricated conditions. Results are presented for the simulation of a single-cylinder engine and show clearly the variations in the secondary translation and rotation of the piston throughout the engine cycle for the non-lubricated condition, and the significant damping of such secondary motions in the fully flooded lubricated condition.

The Effect of Prickly Poppy Methyl Ester Blends on Ci Engine Performance and Emission Characteristics

Abstract: Problem statement: The aim of this research was to investigate the effect of using Prickly poppy methyl ester as a fuel blend on Diesel engine (CI engine) performance and exhaust emission. Approach: Short-term engine performance tests were conducted to evaluate and compare the use of various diesel fuel supplements at blend rations of 60/40, 70/30, 80/20, 90/10, in a standard, fully instrumented, four stroke, Direct Injection (DI), Kirlosker comet Diesel engine located at the authors’ laboratory. The prickly poppy oil with high free fatty acid is not used as edible oil, it can be considered as a potential source of non edible oil for utilization as a feed stock vegetable oil for bio diesel production. The prickly poppy oil was subjected to esterification and transesterification processes and the Prickly Poppy Methyl Ester (PPME) obtained was tested as supplement. Results: The test showed that PPME blends with diesel could be conveniently used as a diesel substitute in a diesel engine. The test further showed increase in break thermal efficiency, brake power and reduction of specific fuel consumption for PPME and its blends with diesel generally, but the most significant conclusion from the study is that the 80 % Diesel / 20% PPME blend produced maximum values of the brake power, brake thermal efficiency and minimum values of the specific fuel consumption and also yielded minimum values of NOx, CO and HC emission. Conclusion: Using Prickly Poppy Methyl Ester (PPME) as a bio fuel blend with Diesel shows an improvement in performance and significant reduction in exhaust emission for the generation of cleaner environment.

Performance and emission characteristics of a ci engine operated on vegetable oils as alternative fuels

Abstract: An experimental analysis is done on four stroke single cylinder constant speed, water cooled diesel engine which is interfaced with Engine soft software. Performance and emission characteristics are evaluated for three non-edible vegetable oils viz. thumba, jojoba, neem and jojoba methyl ester to study the effect of injection pressures viz. 205, 220, 240 and 260 bar with variation in injection timing at 23°bTDC and 28°bTDC. The performance of jojoba methyl ester improved with increase in injection pressures, maximum brake thermal efficiency of 29.72% is obtained with lower emissions compared to other vegetable oils; the reason might be low viscosity and better combustion. Further investigations were carried out with new lubricant SAE 5W-30; which improved the performance of CI engine by 1.59%. All the above investigations were fruitful and these results are expected to lead to a substantial contribution to the development of a viable vegetable oil engine.

Impact of Methanol–Gasoline Fuel Blends on the Performance and Exhaust Emissions of a SI Engine

Abstract: In this study, the effect of Methanol (M5, M7.5, M10, M12.5, M15) on the performance and combustion characteristics of a spark ignition engine (SI) were investigated. In the experiment, an engine with four-cylinder, four stroke, multipoint injection system (Ford, Zetec-E) was used. Performance tests were conducted for brake torque, brake power, brake thermal efficiency, volumetric efficiency, equivalence air-fuel ratio, and brake specific fuel consumption and exhaust emissions (CO, CO 2 , HC, NO x ) were analyzed under wide open throttle operating conditions and variable engine speed ranging from 1500 to 5000 rpm. The experimental results showed that the performance of engine was improved with the use of methanol. It was also shown that CO and HC emissions were reduced with the increase of methanol content while CO 2 and NOx were increased.

Evaluation of Performance and Emission characteristics of Turbocharged Diesel Engine with Mullite as Thermal Barrier Coating

Abstract: Tests were performed on a single cylinder, four stroke, direct injection, diesel engine whose piston crown, cylinder head and valves were coated with a 0.5 mm thickness of 3Al2O3 .2SiO2 (mullite) (Al2O3= 60%, SiO2= 40%) over a 150 µm thickness of NiCrAlY bond coat. Tests were carried out on standard engine (uncoated) and low heat rejection (LHR) engine with and without turbocharger. This paper is intended to emphasis on energy balance and emission characteristic for standard engine (uncoated) and low heat rejection (LHR) engine with and without turbocharger. Tests were carried out at different engine load and engine speed conditions for standard and low heat rejection engine with and without turbocharger. The results showed that there was 2.18% decreasing on specific fuel consumption value of low heat rejection (LHR) engine with turbocharger compared to standard engine at full load. There was as much as 12% increasing on exhaust gas temperature of LHR engine with turbocharger compared to standard engine at full load. There was as much as 20.64% increasing on NOx emission of exhaust gas, 22.05% decreasing on CO emission of exhaust gas and 28.20% decreasing on HC emission of exhaust gas of LHR engine with turbocharger compared to standard engine at full load.

Experimental investigation on Zirconia coated high compression spark ignition engine with ethanol as fuel

Abstract: This study presents effect of coating on piston, cylinder head, and valves on the performance of a modified four stroke diesel engine using wet ethanol (5% water) as a fuel and emission characteristics of exhaust gas. Zirconia, which has low thermal conductivity, high temperature resistance, chemical inertness, high resistance to erosion, corrosion and high strength, was selected as a coating material for engine components. Ethanol was sprayed in inlet manifold and spark plug was erected on engine head to facilitate ignition. Engine’s performance was studied for both wet ethanol and diesel with and without Zirconia coating. Also, emissions values were recorded to study the engine’s behavior on emissions.

Performance analysis of a 4-stroke SI engine using CNG as an alternative fuel

Abstract: The research on alternative fuels has become essential due to depletion of petroleum products and its major contribution for pollutants. In the present work, Compressed Natural Gas (CNG) has been introduced as an alternative fuel to overcome the above problems. Of the higher compression ratio, higher octane number, the CNG is used to allow the combustion without knocking. The emission characteristics of HC and CO are better for CNG compared to petrol. In this work experimental investigations have been carried out pertaining to the engine performance and exhaust emissions of a single cylinder 4-stroke air cooled type Bajaj-Kawasaki engine

Experimental investigation on a diesel engine using neem oil and its methyl ester

Abstract: Fuel crisis and environmental concerns have led to look for alternative fuels of bio-origin sources such as vegetable oils, which can be produced from forests, vegetable oil crops and oil bearing biomass materials. Vegetable oils have energy content comparable to diesel fuel. The effect of neem oil (NeO) and its methyl ester (NOME) on a direct injected four stroke, single cylinder diesel engine combustion, performance and emission is investigated in this paper. The results show that at full load, peak cylinder pressure is higher for NOME; peak heat release rate during the premixed combustion phase is lower for neat NeO and NOME. Ignition delay is lower for neat NeO and NOME when compared with diesel at full load. The brake thermal efficiency is slightly lower for NeO at all engine loads, but in the case of NOME slightly higher at full load. It has been observed that there is a reduction in NOx emission for neem oil and its methyl ester along with an increase in CO, HC and smoke emissions.

Internal combustion engine with hydraulically-affected stroke

Abstract: An internal combustion engine may include a cylinder block defining a cylinder and a crankshaft having a crankpin. The crankshaft is rotatably received by the cylinder block and rotates along a longitudinal axis, and the crankpin defines a longitudinal axis parallel to and offset by a distance with respect to the longitudinal axis along which the crankshaft rotates. The engine may further include a piston configured to reciprocate within the cylinder and a connecting rod operably coupled to the piston and the crankpin. At least one of the piston and the connecting rod is configured such that a distance between a cross-sectional center of the crankpin and an upper surface of the piston is variable via hydraulic operation.

Gas balanced cryogenic expansion engine

Abstract: An expansion engine operating on a Brayton cycle which is part of a system for producing refrigeration at cryogenic temperatures that includes a compressor, a counter-flow heat exchanger, and a load that may be remote, which is cooled by gas circulating from the engine. The engine has a piston in a cylinder which has nearly the same pressure above and below the piston while it is moving. Low pressure on a piston drive stem provides a force imbalance to move the piston towards the warm end.

Automobile-mount diesel engine with turbocharger and method of controlling the diesel engine

Abstract: An automobile-mount diesel engine with a turbocharger is provided, which includes an engine body with the turbocharger, the engine body being mounted in the automobile and supplied with fuel containing diesel fuel as its main component, a fuel injection valve arranged in the engine body so as to be oriented toward a cylinder of the engine body and for directly injecting the fuel into the cylinder, an injection control module for controlling a mode of injecting the fuel into the cylinder through the fuel injection valve, and an EGR amount control module for adjusting an amount of EGR gas introduced into the cylinder. EGR and fuel injection are adjusted based on speed-load conditions of the engine.

Effect of Ethanol-Gasoline Blends on Fuel Properties Characteristics of Spark Ignition Engines

Abstract: This paper investigates the effect of ethanol-gasoline blends on fuel properties characteristics of variable speed spark ignition (SI) engines using standard laboratory methods. Fuel properties tests were conducted for density, API gravity, kinematic viscosity, cloud point, flash and fire point, heat value, distillation and Octane number using ethanol-gasoline blends with different percentages of ethanol. The blends selection was based on successful completion of engine standard short test carried out on a computerized four cylinders, four stroke, and variable speed SI engine with eddy current dynamometer and data logging facilities. Fuel properties test results showed that blends densities and kinematics viscosity increased continuously and linearly with increasing percentage of ethanol, while API gravity and heat value decreased with decreasing percentage of ethanol. Furthermore, cloud point, flash and fire points for blends were found to be higher than pure gasoline fuel, while distillation curves were lower. The tested blends Octane rating based on Research Octane Number (RON) increased continuously and linearly with increasing percentage of ethanol. Results from this study will be valuable on the assessment of the suitability of ethanol-gasoline blends as bio-fuel for automotive industry to cater for the country needs. Keywords : Spark ignition engine; Bio-fuel; Ethanol; Fuel properties characteristics .

A two-stroke internal combustion engine, method operating a two-stroke internal combustion engine and method of converting a two-stroke engine

Abstract: The invention relates a two-stroke internal combustion engine (10) comprising at least one cylinder (20) with a piston (24) arranged reciprocateably between its top dead center and bottom dead center, and a cylinder cover (26) defining a combustion chamber (22), oxygen containing gas inlet (18) in the lower part of the cylinder (20) to be open into the combustion chamber (22) at least while the piston is at its bottom dead center position, a gaseous fuel inlet (30) arranged in the cylinder between the oxygen containing gas inlet (18) and the cylinder cover(26), and an exhaust valve (28) arranged to the cylinder cover at a center axis of the cylinder. The cylinder cover(26) is provided with pilot ignition pre-chambers (36) opening into the combustion chamber (22) through pre-chamber ports (34). Invention relates also to method of operating a two-stroke engine (10).

Internal combustion piston engine with a compression relief engine brake

Abstract: An internal combustion piston engine based on a four-stroke process, including a crankcase in which at least one cylinder/piston assembly is arranged, the piston being guided by a connecting rod connected to a crankshaft. At least one cylinder head closes the cylinder, each of whose intake and exhaust channels are controlled by at least one intake valve and one exhaust valve ( 13, 13 a ). The intake and exhaust valves ( 13, 13 a ) are actuable by a rocker arm ( 5 ) or a finger lever driven by a camshaft ( 1 ) through intake and exhaust cams ( 2 ). The rocker arms or finger levers are guided on at least one axle ( 6 ). A brake control device is provided which includes, in the region of the base circle of the exhaust cam ( 2 ), at least one additional cam ( 1 ) for an additional opening of at least one of the exhaust valves ( 13, 13 a ). A control element ( 12, 12 a ) is installed between the rocker arm ( 5 ) or finger lever and the exhaust valve or valves ( 13, 13 a ), which control element ( 12, 12 a ) can be connected to the pressurized oil circulation system of the internal combustion piston engine and whose length can be varied, so that the additional cam ( 3 ) is active during a braking operation and inactive during a pure engine operation. The control element ( 1 2) is arranged in a bridge ( 11 ) that is associated with a plurality of exhaust valves ( 13, 13 a ).

Method for the determination of the pressure in the combustion chamber of a large diesel engine and large diesel engine

Abstract: A method is proposed for the determination of the pressure in a combustion chamber (8) of a large diesel engine having at least one cylinder (2) in which a piston (3) delimiting the combustion chamber (8) can be moved back and forth and which is connected by means of a piston rod (4) to a crosshead (5) being movable in a crosshead guide which in turn is connected to a crankshaft (7) by means of a connecting rod (6). The acceleration of the crosshead (5) is measured by means of a sensor device (9) and said acceleration is used for the determination of the pressure in the combustion chamber (8). In addition, a large diesel engine is proposed.

Computer Aided Modeling and Optimization of Crankshaft

Abstract: The Computer aided modeling and optimization analysis of crankshaft is to study was to evaluate and compare the fatigue performance of two competing manufacturing technologies for automotive crankshafts, namely forged steel and ductile cast iron. In this study a dynamic simulation was conducted on two crankshafts, cast iron and forged steel, from similar single cylinder four stroke en- gines.Finite element analyses was performed to obtain the variation of stress magnitude at critical locations. The dynamic analysis was done analytically and was verified by simulations in ANSYS.Results achived from aforementioned analysis were used in optimization of the forged steel crankshaft.Geometry,material and manufacturing processes were optimized considering different constraints,manufacturing feasibility and cost.The optimization process included geometry changes compatible with the current engine,fillet rolling and result in in- creased fatigue strength and reduced cost of the crankshaft, without changing connecting rod and engine block.

Jet exhaust piston engine

Abstract: This invention is a piston in cylinder engine using water injection into a relative vacuum heated to steam by expanding in the cylinder and by an electric arc or other heat source. The resulting steam explosion applies a work force on the piston. The piston has jet nozzles uncovered at the end of its work stroke to jet the piston to help propel it during the return stroke and to form a vacuum in place of the usual compression stroke. The piston has a cover plate with tapered pins depending into jet nozzles through the piston to block the jet nozzles during the main work stroke.