Showing papers on "Diesel engine published in 1974"

Air Motion in a Four-Stroke Direct Injection Diesel Engine

Abstract: This paper presents the results of a study of the air motion in a motored four-stroke direct injection diesel engine using hot-wire anemometry.The effects of engine speed, valve masking and superch...

Photographic and Performance Studies of Diesel Combustion With a Rapid Compression Machine

Abstract: Photographic and performance studies with a Rapid Compression Machine at the Massachusetts Institute of Technology have been used to develop insight into the role of mixing in diesel engine combustion. Combustion photographs and performance data were analyzed. The experiments simulate a single fuel spray in an open chember diesel engine with direct injection. The effects of droplet formation and evaporation on mixing are examined. It is concluded that mixing is controlled by the rate of entrainment of air by the fuel spray rather than the dynamics of single droplets. Experimental data on the geometry of a jet in a quiescent combustion chamber were compared with a two-phase jet model; a jet model based on empirical turbulent entrainment coefficients was developed to predict the motion of a fuel jet in a combustion chamber with swirl. Good agreement between theory and experiment was obtained. The fuel and air mixing rate was estimated from the jet models and compared with combustion rates measured in the Rapid Compression Machine.

First Paper: Measurement of the Oil-Film Thickness between the Piston Rings and Liner of a Small Diesel Engine

Abstract: A capacity gauge has been designed for operating in the conditions of a working engine. The method of using it for determining the oil-film thickness and piston-ring profile is described. Oil-film thicknesses in the range 0·4-2·5 μm between the piston rings and the cylinder liner have been observed. Their variation with speed, load and temperature has been measured and it is concluded that their behaviour is essentially hydrodynamic.

Exhaust gas recirculation system for internal combustion engines

Abstract: Apparatus for electronically controlling exhaust gas recirculation in an internal combustion diesel engine to reduce nitrogen oxide emissions. An exhaust gas recirculation control valve is driven by a feedback circuit which compares the valve position with the engine load. A maximum amount of exhaust gas is recirculated under a no-load condition. As the load increases to 100%, the amount of recirculated exhaust gas is decreased down to zero percent. The amount of recirculated exhaust gas also may be affected by the engine speed to minimize smoke in the engine exhaust.

Device for feeding fuel to a diesel engine

Abstract: A device for feeding fuel to a diesel engine including a fuel storage tank, a feed pump provided in a conduit between the fuel storage tank and the engine, and an injection pump for atomization. The injection pump is provided with a pressure control valve for reducing the excessive pressure to that of the pressure prevailing in the conduits and with a device for measuring the fuel consumption. Means are provided for substantially equalizing the temperature of the fuel in a return conduit and in the feed conduit, and for holding the fuel under excessive pressure in the feed conduit.

Method and means for conditioning the intake air of a supercharged, low-compression ratio diesel engine

Abstract: A method of and means for conditioning a substantially highly supercharged, low-compression ratio Diesel engine at start and low-load or idling speed operation wherein the improvement consists in the step of temporarily preheating the air supply before it enters or is pressure fed into the combustion chambers of the engine cylinders.

Improvement in methods of supercharging an engine, preferably a diesel engine in such supercharged engines, and in supercharging units for such engines

Abstract: An internal combustion engine of the expansible chamber type and preferably a diesel engine is equipped with a turbo-compressor unit, comprising at least one compressor and at least one turbine, and at least one bypass pipe enabling direct and permanent passage for the air delivered through the compressor to the turbine inlet The diesel engine is supercharged by the compressor driven by the turbine Regulating means are provided to limit the rotary speed of the supercharging unit so that it operates at or above a minimum threshold value such that the engine, which has a compression ratio of less than 12, can be started and kept running at low power without difficulty For engines requiring scavenging, throttle means with variable passage cross section are arranged so as to be traversed by generating between the upstream and downstream parts of the bypass pipe a pressure difference which is an increasing function of the pressure existing in the upstream part regardless of the engine speed and therefore which is independent of the air flow passing through said throttle means The increasing function may be a linear or substantially linear function A combustion chamber is arranged upstream of the turbine and supplied by air which has passed through the bypass pipe, by fuel under the control of the regulating means and also, in some embodiments, by exhaust gases from the engine

Main combustion chamber of swirl chamber type diesel engine

Abstract: A main combustion chamber that permits efficient combustion throughout the entire rotation range comprising a groove extending diametrically from an edge portion of the top surface of a piston and a pair of twin-leaved recesses branched from amidst the groove, each one of the pair of twin-leaved recesses have an edge portion that is circular or otherwise. Both the groove and the recesses are formed in the top surface of a piston of a swirl chamber type diesel engine.

Unit injector for a diesel engine

Abstract: A unit injector for a diesel engine wherein a spool valve body is connected with a pressurizing chamber in a main body so that fuel to be supplied from a fluid element is supplied into the pressurizing chamber to affect the injection stroke of a pump plunger and the spool valve is actuated by the supplied fuel pressure to be supplied by the fluid element.

Emissions Study of A Single-Cylinder Diesel Engine

Abstract: Exhaust measurements of NO, soot, and hydrocarbons were made on a 2340-cm3 displacement, single-cylinder diesel engine operated over a range of speed, fuel-air ratio, and timing. Modifications systematically tested include (1) chamber shape (open and divided chamber, prechamber volume ratio, and compression ratio), (2) air swirl, (3) thermodynamic state of the intake charge (EGR, turbocharging, water injection, and air temperature), and (4) fuel injection parameters (orifice size, rate of injection, cam shape, pilot injection). Exhaust data suggest that the phenomena of air swirl, fuel spray, and diffusion flames are key elements in diesel combustion behavior. The sensitivity of emissions to time-dependent phenomena such as mixing rates, ignition, heat transfer, and burning rates is apparently connected to the extent to which heat release is delayed.

Precombustion chamber rotary piston diesel engine

Abstract: The system and method of this invention is directed to effecting combustion of fuel in a rotary piston, internal combustion engine having a housing defining a trochoidal-shaped, multi-lobe cavity in which a rotor is mounted for planetary rotation and defines with the housing working chambers that successively expand and contract in volumetric size as the rotor orbits within the housing cavity. The system and method comprises a precombustion chamber which communicates with successive working chambers through an outlet port. When the outlet port is open to the working chamber at approximately the initiation of the expansion cycle of the working chamber, all the fuel for a particular engine operating condition of speed and load is mixed in the precombustion chamber with a relatively small quantity of air at a pressure substantially greater than the pressure in the working chamber to thereby cause ignition and flash of the fuel into the working chamber. Complete combustion of the fuel rich mixture flashed into the working chamber is supported by the air compressed in the working chambers.

Optimal control considerations of diesel engine discrete models

Abstract: Recently proposed discrete-model representation of turbo-charged diesel engines are recast in state-space form and used in an optimal control study. It is known that the turbo-charger has considerable influence on the dynamical behaviour of the engine and this is accounted for by incorporating a weighting of the air-fuel ratio in the performance index. This leads to a rather unusual form of the quadratic performance functional and the optimal controls are determined using both dynamic programming and discrete minimum principle techniques. This leads to extensions and some simplification of known theoretical results.

Simulation and optimization of thermodynamic processes of diesel engine.

Abstract: A mathematical model of an open-chamber diesel engine has been programmed for solution on a digital computer. The program incorporates an automatic procedure which, given the limits of design variables, will predict the values of these variables that will optimize engine performance. This technique can provide these results in a fraction of the time taken by parametric methods and provides a quick and efficient tool that can be used directly by the designer or the development engineer. Examples are given to demonstrate how the technique can be employed to maximize engine power to torque.

Diesel engine fuel injection pump governor

Abstract: A control lever and flyweight assembly move a floating lever which determines the position of a control rod which controls the fuel injection volume A novel linkage including a profiled cam is engagable with the flyweight assembly and the control rod to limit the fuel injection volume to a level at which smoky exhaust gases are not produced Compensating means are engagable with the linkage to compensate for variations in temperature and pressure

Combustion chamber of a direct fuel injection type diesel engine

Abstract: A combustion chamber of a direct fuel injection type diesel engine has a cavity at the crown of a piston, within which a swirl occurs and onto which fuel is injected from a multi-orifice fuel injection nozzle toward a inner side wall of the cavity. The cavity is regular polygonal in horizontal cross-section. The inner side wall is so inclined inwardly of the cavity as to provide a restriction at the opening of the cavity. The inner side wall and the injection nozzle are so arranged that the fuel jet is distributed to the downstream side of the swirl after being impinged the inner side wall, whereby the distribution of the injected fuel is improved to provide ideal mixture in the cavity, resulting in reduced amount of pollutant emissions.

Diesel fuel line heater

Abstract: An arcuate chamber, fitted against a portion of a replaceable fuel line filter for a diesel engine includes an inner high heat transfer material adjacent the filter element, inlet and outlet lines for the chamber for passing engine exhaust gases, an exhaust flow control valve, and a releasable fastener securing the chamber to a filter element.

Diesel engine intake air preheater fuel control

Abstract: A metering and control system is described for supplying fuel to a burner nozzle of a burner assembly which preheats intake air in a diesel engine. Fuel for the control system is derived from the regulated pressure output of a fuel pump in the engine fuel supply system. The fuel metering and control system includes a series of parallel flow lines connected between the fuel pump and the burner nozzle. Each line has a metering orifice and check valve set to pass flow above a given pressure level. For intermediate rpm flow is through one line and at high rpm flow is through both. As a result, the fuel flow rate into the burner nozzle is directly proportional to engine rpm to provide a uniform nozzle preheat temperature over the full range of engine rpm. Suitable control inputs are provided to initiate or terminate flow to the burner in response to selected engine operating parameters. In addition, supplemental fuel flow may be provided during start up and/or cold operating conditions, again initiated or terminated by selected engine operating parameters.

Supercharged diesel engine fuel injection pump governor assembly

Abstract: A manual speed control member and a centrifugal governor act in combination to select a desired position for a fuel injection pump control rod to control the fuel injection volume. A pressure sensitive unit acts to limit movement of the control rod in a direction to increase the fuel injection volume to a point where maximum power is obtainable but smoky exhaust is prevented. The pressure sensitive unit is automatically disconnected from the control rod to provide maximum fuel injection volume for starting the engine.

Effect of Diesel Fuel Properties on Emissions and Performance

Abstract: Tests were conducted with several production diesel engines and one prototype low-emission diesel engine to determine the effect of fuel properties on exhaust emissions and engine performance. Fuel cetane number was the most significant fuel property; low cetane fuels resulted in higher hydrocarbons and oxides of nitrogen and increased noise. Conversely, higher cetane fuels produced lower emissions and noise, and also improved engine starting characteristics. The degree of these effects was influenced by engine configuration. Although engine design changes can result in substantial emissions reduction, fuel properties can also influence achievable levels.

Application of electro-optical techniques in diesel engine research

Abstract: This paper presents preliminary results of studies of the feasibility of applying electro-optical diagnostic techniques to diesel engine research. A 2-cycle, 3-cyl, diesel engine was modified by installing quartz windows in the combustion chamber to provide optical access. Techniques investigated include photography, holography, laser resonance absorption spectroscopy, and laser velocimetry. Droplet formation, breakup, and combustion can be observed in the combustion chamber in three dimensions using holography. The same hologram can be used for particle sizing and flow visualization studies. Formation of certain hydrocarbons can be observed in real time with resonance absorption, using a tunable He-Ne laser.

Internal combustion engine, particularly a diesel engine

Abstract: An internal combustion engine, in particular a Diesel engine, comprising at least one inlet duct consisting of a delivery portion and an adjoining duct portion wound spiral-fashion around the shaft of the associated intake valve, the upper wall of which bulges downwardly at the point of transition from the delivery portion to the spiral-shaped duct portion in such a manner that the cross-sectional area of the inlet duct is reduced above the valve diameter extending at a right angle in relation to the axis of the delivery portion.

Sampled-data frequency response measurements of a large diesel engine

Abstract: The work describes the application of the authors’ previously described work, on achieving repeatable frequency response measurements from sampled-data systems, to a large diesel engine. A review is made of the salient points necessary to appreciate the measurements and various problems that occurred during the experiments are discussed. Experimental evidence is presented showing that once the essential sampled nature of a reciprocating engine is recognized, and allowed for, the engine control system should be capable of being designed systematically.

Combustion chamber for supercharged internal combustion engine

Abstract: An auxiliary combustion chamber for use with a supercharged Diesel engine comprises a fuel injection and spraying device adapted to operate with delivery rates which are variable within a broad range. The device has a fuel injection port which opens into the chamber. The size of the port is such that the fuel is mechanically atomized when injected at the maximum rate. Air passage nozzles open into the combustion chamber at a location close to the port and deliver air jets at a speed and at a delivery rate sufficient for it to atomize the fuel effectively at minimum fuel delivery rate.

Effect of very low air intake temperature on the performance and exhaust emission characteristics of a diesel engine

Abstract: Operational and exhaust emission characteristics of a single cylinder direct injection diesel engine are described. It was operated warm under a wide range of intake air temperatures extending down to -45 F and occasionally -60 F. The smoke density increased at the very low load range mainly associated with the greater production of aerosol or cold smoke. At lower intake temperature, this increase at light load and partial motoring range became particularly high despite the increased mass of air being induced. For the low load range, the exhaust was almost totally opaque at subzero temperatures. The concentration of carbon monoxide under very light load or partially motored conditions associated with cold or aerosol smoke emissions was many times that observed for the same engine at higher loads. The nitrogen oxides exhaust emission for any fueling rate decreased significantly with the reduction of intake temperature. The concentration of nonutilized oxygen in the exhaust gas for any fueling rate increased with the lowering of intake temperature, reflecting the deterioration of fuel utilization and increased mass flow with a reduction of temperature.

Diesel engine and cylinder head therefor

Abstract: A two-stroke cycle uniflow diesel engine having large closely spaced cylinders includes a novel trapezoidal valve arrangement providing improved gas flow while meeting limitations of components common with another engine line and cooling system improvements including an improved flow director tube and sealing arrangement providing adequate cooling flow between the cylinders in a reduced space dictated by the larger cylinders.

Supercharged diesel engines and methods of starting them

Abstract: The diesel engine has a closed cooling system traversed by a liquid and a supercharging unit whose turbine is supplied by exhaust gases through a combustion chamber, and whose compressor supplies, on one hand, the engine through a cooler mounted in said cooling system, and, on the other hand, said combustion chamber. A by-pass pipe is arranged in parallel with the cooler, distributing means being provided at the beginning of this bypass pipe, these distributing means being controlled so that, during the period of starting and rise in temperature of the engine, a part at least of the air delivered by the compressor passes through the by-pass pipe.