Showing papers on "Spark-ignition engine published in 1981"

Hydrocarbon Oxidation in the Exhaust Port of a Spark Ignition Engine

Abstract: An experimental study was performed to determine the fraction of unburned hydrocarbon emissions which are oxidized in the exhaust port of a spark ignition engine. The technique used was injection of a CO//2 quench gas into the exhaust port, at various planes along the port centerline, to cool the exhaust gas and "freeze" the hydrocarbon oxidation reactions. By quenching the reaction of hydrocarbons at the cylinder exit plane, cylinder exit hydrocarbon emissions levels were determined. By differencing the concentration of hydrocarbons observed during quenching and nonquenching operation, the fraction of hydrocarbons reacting in each section of the exhaust was determined. Experiments were carried out to define the effects of engine operating conditions on the fraction of hydrocarbons oxidized.

The Effects of Alcohol Fuels and Fully Formulated Lubricants on Engine Wear

Abstract: An investigation of the effects of alcohol fuels and lubricant formulations on spark ignition engine wear and deposition was made Tests were conducted using near methanol, anhydrous ethanol, and alcohol blends as fuel in a 23-liter engine using a modified ASTM Sequence V-D test procedure

On the correlation between gas velocity and combustion pressure fluctuations in a spark-ignition engine

Abstract: The interaction between a fluctuating velocity field and spark ignited combustion in a lean burning engine has been studied using conditionally sampled laser-Doppler anemometry. The measurements show a strong correlation between relatively large scale velocity fluctuations in the spark gap region of the cylinder at the ignition timing and the ultimate combustion efficiency. A much weaker correlation between high frequency turbulence and combustion pressures was observed. A development of the technique that allowed measurements to be made on each cycle of the engine showed that the dominant contribution to the total turbulence intensity in the cylinder is from large scale low frequency fluctuations.

Studies of combustion and crevice gas motion in a flow-visualization spark-ignition engine

Abstract: Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1981.

Electronic controller of spark-ignition engine

Abstract: PURPOSE:To improve exhaust emission from an engine without deteriorating its output performance, by variable controlling an intake state and performing feedback control of a combustion delay period. CONSTITUTION:Combustion timing is arithmetically operated by a combustion timing detector circuit 43 on the basis of outputs from a cylinder pressure sensor 38 and crank angle sensor 41. This combustion timing signal is input to a combustion delay detector circuit 44 with an ignition timing signal 37, and a clock signal, from input of the signal 37 to input of the combustion timing signal, is counted to obtain a combustion delay signal, then the combustion delay siganl of several cycles is averaged by an equalizer circuit 46 and input to a comparator circuit 48. Here the signal is compared with a reference value corresponding to a target combustion period in accorddnce with an operating condition from a target value table 47, and this result controls on-off proportion of a control pulse to a solenoid valve 25 through an exhaust gas recirculating (EGR) amount control circuit 49, to change negative pressure fed to an EGR valve 26 and control an EGR amount.

The rapid measurement of approximate flow velocities in an internal combustion engine using photon correlation laser anemometry

Abstract: A method has been developed which allows rapid estimates to be made of flow velocities in a spark ignition engine. The information obtained from the laser-Doppler anemometry facility was processed using an original algorithm to extract mean velocities from individual cycles. The results indicated that most of the turbulence in the engine studied consists of relatively large-scale, low-frequency fluctuations which are conventionally interpreted as cyclic differences in mean velocity. These large flow structures also have the dominant effect in the generation of cyclic variations of combustion efficiency.

Intake gas recirculation.

Abstract: The present invention refers to the adapting of an internal combustion spark ignition engine to a multifuel engine having maximum thermodynamic efficiency possible with each particular fuel. The innovation consists in the variation of an effective compression ratio of the engine by recirculation of unburned gases from the cylinder to the intake tube (9) of the engine in a certain extent of the compression stroke of the engine. The recirculation of the intake gases is controlled by an actuating device (5) with variable action. The basic effect of the invention is to confer to the engine the property of having a variable effective compression ratio optimized for a particular fuel and at the same time to use a large expansion ratio, being constant and independent of the compression ratio, in order to obtain a high thermodynamic efficiency and a low specific fuel consumption. The invention can be applied on existing engines or on new engines in order to get a highly efficient use of volatile or gaseous fuels, such as some petroleum derivates and its alternative fuels like the alcohols and biogases.

Improvements in split cycle internal combustion engines

Abstract: A split cycle internal combustion spark ignition engine having a firing cylinder (10) and a compression cylinder (11) each with pistons connected to a common crankshaft. To enable spark ignition at a voltage giving acceptable spark plug life while retaining the advantages of high combustion chamber pressure is initially contained by admitting a pilot charge of fuel-air mixture at a pressure below 2000KPa, spark igniting the pilot charge at or near top dead centre and then, early in the power stroke, admitting a second charge of air-fuel mixture compressed to a pressure greater than 2000KPa for ignition by the burning pilot charge.

Capacitor ignition system for internal combustion engines

Abstract: This ignition system is based on the principle of energy storage in the ignition coil inductor. Here, the energy is output by a direct voltage transformer, prestored in a capacitor C5 and then fed to the ignition coil inductor L by means of a thyristor which is controlled by the breaker contact. A strong and enduring ignition spark is induced during the repeated exchange of electrical and magnetic energy between capacitor C5 and L of the ignition coil which now follows. C5.U DIVIDED 2 = L.I DIVIDED 2 A further oscillatory circuit extends the spark firing period. The said circuit consists of C6 and also of the ignition coil inductor L and oscillates with the residual energy of the ignition coil. C6 at the same time forms the R.C wiring for the thyristor in conjunction with the output resistance of the transformer. The problem of blocking the thyristor again after firing was solved by deactivating the transformer for a time > oscillation period T. In motor vehicles with a spark ignition engine, a fuel saving of approximately 10% is achieved. And the strong ignition spark also provides possibilities of using totally different types of fuel. An electrical circuit diagram (8) which is enclosed with the application clarifies the function of the capacitor ignition system.

Air/fuel ratio control mechanism of alcohol engine

Abstract: PURPOSE:To reduce aldehyde exhaust from a spark ignition engine using alcohol mixture as fuel by sending the secondary air to the upper side of an air-fuel sensor in the flow of mixture in accordance with the alcoholic density. CONSTITUTION:The aldehyde content in an exhaust gas becomes higher with the excess air factor and the alcohol share. A 3-way valve 13 interlocked with a servo motor 14 is controlled by signals from an alcoholic density sensor 8 equipped at the fuel tank 7 and, according to the sensed density, the secondary air from air pump 10 is sent to the upper side of an air-fuel ratio sensor in flow by a nozzle 17. Thus, an air-fuel ratio sensor equipped in the exhaust gas line located after three- dimensional catalizer will sense the object including the oxygen in the secondary air. Accordingly, combustion is made in the engine on the side richer than the theoretical air-fuel ratio, that will contribute to reduce the aldehyde exhaust.

Combustion chamber for spark ignition engine

Abstract: PURPOSE:To restrain a knocking caused in a high throttle running for a higher driving power by providing squish areas inside a combustion chamber and forming indents in a combustion chamber's wall face in the vicinity of two ignition plugs. CONSTITUTION:A suction valve 2 and an exhaust valve 3 are disposed nearly symmetrically with respect to a center of a cylinder bore 11. Two squish areas 6, 6' opposed to each other are formed outside ignition plugs 5, 5' and laid along a circumference of the cylinder bore 11. Indents 19, 19' are formed in a piston combustion chamber's wall face at positions 20, 20' in the vicinity of the ignition plugs 5, 5'. With the ignition plugs 5, 5' centered, nearly spherical indents 15, 15' are formed in a combustion chamber's wall face 7 in the vicinity of the ignition plugs 5, 5'. There exists no low temperature combustion chamber which impedes growth of a flame, around ignition tips 14, 14'. Thereby the flame may grows freely. This may restrain a knocking caused in a high throttle running and provide higher driving power. In addition, bacause a burning during a partial throttle running is well enough to give a satisfacotory effect of high compression ratio, fuel consumption may be improved.

Effect of compression ratio on the performance of a spark ignition engine fueled with methanol and ethanol

Abstract: Experimental work was conducted on a four-cylinder passenger car engine to investigate the technical aspects of neat ethanol, methanol and ethanol - and methanol-water blends as automotive fuels and results are directly compared to gasoline. Considerable improvements in engine performance were realized with alcohols and alcohol-water blends at elevated compression ratios. 18 refs.

Spark ignition IC engine - has fuel mixture optimised for middle load with auxiliary engine coupled at upper middle or upper ranges

Abstract: The spark ignition engine (1) varies ignition timing with constant high air excess and constant charge when running in the lower middle load range The charge is varied with constant high air excess and constant timing in the lower load range, whilst in the upper range the mixture is enriched with constant charge The engine is designed to reach maximum output and minimum relative fuel consumption within this middle range, whilst in the upper or in the upper middle load range, an auxiliary engine (2) is coupled to the engine output This auxiliary engine then runs near its full output with constant optimum timing

Improvement of combustion in spark ignition engine with yics

Abstract: This report concerns the introduction of the Yamaha Induction Control System (YICS), which promotes rapid combustion of fuel in spark ignition engines by forcing a swirling motion in the cylinder charge. This increases the combustion rate and reduces fuel consumption. (Author/TRRL)

Spark ignition internal combustion engine

Abstract: A split cycle internal combustion spark ignition engine having a firing cylinder (10) and a compression cylinder (11) each with pistons connected to a common crankshaft. To enable spark ignition at a voltage giving acceptable spark plug life while retaining the advantages of high combustion chamber pressure is initially contained by admitting a pilot charge of fuel-air mixture at a pressure below 2000KPa, spark igniting the pilot charge at or near top dead centre and then, early in the power stroke, admitting a second charge of air-fuel mixture compressed to a pressure greater than 2000KPa for ignition by the burning pilot charge.

The Power Control System for the Ford-Philips Stirling Engine

Abstract: A reliable power control system was developed for the Stirling engine. This control system provides a stable engine speed and an engine speed-accelerator pedal position relationship similar to a spark ignition engine, allowing a driver to operate a Stirling-powered vehicle in a conventional manner.

Knock-limited performance of ethanol blends in a spark-ignition engine

Abstract: An experimental study was performed to determine the effect of varying percentages of ethanol in fuel using a CFR engine operated at knock-limited compression ratio and maximum power spark timing. Blends of 85 octane primary reference fuel and ethanol in concentrations between 10 and 25% by volume were tested for performance, fuel economy, and exhaust emissions. The results indicated that when the engine was operated at knock-limited conditions at a constant equivalence ratio, the use of ethanol resulted in a reduction in petroleum fuel usage of 10% greater than the volumetric percentage of the ethanol used in the blend. These results were independent of the amount of ethanol used in the blend. Under these conditions, as the ethanol concentration was increased, BMEP and BSHC increased, BSNO and BSCO remained essentially constant, and exhaust temperature decreased.

Engine electrical system test device

Abstract: A spark ignition engine tester for inserting between pairs of normally interconnected releasable connectors in the high voltage portion of the engine's spark ignition system, as between a spark plug terminal and the corresponding wire from the distributor, and between the high voltage output terminal of the coil and the wire to the distributor. The tester includes first and second electrodes with adjacent ends separated by a visible spark gap and remote ends for connection to the ignition system high voltage portion. An insulator supports the two electrodes substantially at right angles to each other. A conductive coil spring sleeved over the remote end of an electrode inserts into or sleeves over the opposed releasable connector of the emission system high voltage portion.

Piston for IC spark ignition engine - has two concentric combustion chambers in crown and central spark plug

Abstract: The piston fits in the bore (1) and has piston rings sealing the sides of the bore. The engine cylinder has a central spark plug (3). The piston crown has a central hole (4) around the spark plug. The hole is separated from the external groove (6) by the circular wall (5) occupying about one third of the width of the crown. The piston crown and the cylinder head have a curved section (2). The groove (6) is symmetrical about the corner of the cylinder. Combustion takes place more rapidly in the central chamber (4).

Device for controlling the intake cross-section in the intake line of a spark ignition engine

Abstract: Device for controlling the intake cross-section in the intake line (8) of a spark ignition engine by means of a closing element (7) which can be actuated by an actuator (6), having control electronics (4) which drive the closing element (7) as a function of the position of a set value transmitter (1). This device is to be constructed in such a way that, with simple means, it prevents the engine knocking. This is achieved in that knocking of the engine can be detected by means of a sensor (5) and a corresponding signal can be fed to the control electronics (4) and influences the said electronics (4) to the effect of closing the intake cross-section.

Conventional engine technology. volume 2: status of diesel engine technology

Abstract: The engines of diesel cars marketed in the United States were examined. Prominent design features, performance characteristics, fuel economy and emissions data were compared. Specific problems, in particular those of NO and smoke emissions, the effects of increasing dieselization on diesel fuel price and availability, current R&D work and advanced diesel concepts are discussed. Diesel cars currently have a fuel economy advantage over gasoline engine powered cars. Diesel drawbacks (noise and odor) were reduced to a less objectionable level. An equivalent gasoline engine driveability was obtained with turbocharging. Diesel manufacturers see a growth in the diesel market for the next ten years. Uncertainties regarding future emission regulation may inhibit future diesel production investments. With spark ignition engine technology advancing in the direction of high compression ratios, the fuel economy advantages of the diesel car is expected to diminish. To return its fuel economy lead, the diesel's potential for future improvement must be used.