Showing papers on "Combustion chamber published in 1976"

Models for combustion and formation of nitric oxide and soot in direct injection diesel engines. SAE Paper 760129

Abstract: A mathematical model was developed for predicting the concentration of exhaust nitric oxide, soot and other emissions in a direct injection diesel engine. In the model, it was emphasized to describe the phenomena occurring in the combustion chamber from the microscopic point of view. The prediction was based on the knowledges concerning a single droplet as well as the droplet size distribution in a fuel spray and the spatial and temporal distribution histories of fuel in a combustion chamber. The heterogeneous field of temperature and equivalence ratio, and uniform pressure in the cylinder were postulated. The heat release model gives the burning rate of injected fuel and pressure and temperature history in the cylinder. The concentration of nitric oxide and soot in the cylinder was predicted by the emission formation model. In order to confirm the validity of the theoretical analysis, the calculated results were compared with the experimental results for typical direct injection diesel engine.

Models for combustion and formation of nitric oxide and soot in direct injection diesel engines

Abstract: A mathematical model for predicting heat release rate and emission concentration in diesel engines was developed. In the model, emphasis was placed on the detailed physical processes in the combustion chamber and in employing a minimum of necessary approximations. The ability of the model to predict realistic correlations between engine design and performance parameter was demonstrated. The model is regarded as a potentially useful tool for evaluating approaches for control of exhaust emission.

A transient spray mixing model for diesel combustion

Abstract: A transient spray mixing model forming the basis of heterogeneous combustion in direct injection diesel engines is described. Experimental results of transient fuel sprays in a high pressure, high temperature chamber form the basis of spray growth equations. Progressive evaluation of combustion zones is determined by the fuel-air mixing process. The role of fuel-air mixing in diesel combustion is discussed. The model results are compared with experimental data. /GMRL/

Liquid rocket engine injectors

Abstract: The injector in a liquid rocket engine atomizes and mixes the fuel with the oxidizer to produce efficient and stable combustion that will provide the required thrust without endangering hardware durability. Injectors usually take the form of a perforated disk at the head of the rocket engine combustion chamber, and have varied from a few inches to more than a yard in diameter. This monograph treats specifically bipropellant injectors, emphasis being placed on the liquid/liquid and liquid/gas injectors that have been developed for and used in flight-proven engines. The information provided has limited application to monopropellant injectors and gas/gas propellant systems. Critical problems that may arise during injector development and the approaches that lead to successful design are discussed.

Plasma igniter for internal combustion engine

Abstract: An igniter for the air/fuel mixture used in the cylinders of an internal combustion engine employs a conventional spark to initiate the discharge of a large amount of energy stored in a capacitor. A high current discharge of the energy in the capacitor switched on by a spark discharge produces a plasma and a magnetic field. The resultant combined electromagnetic current and magnetic field force accelerates the plasma deep into the combustion chamber thereby providing an improved ignition of the air/fuel mixture in the chamber.

Effects of Turbulence on Spark-Ignition Engine Combustion

Abstract: The effects of mixture turbulence on combustion in a spark- ignition engine were investigated using a CFR engine. The apparent instantaneous turbulent flame speed during combustion was calculated from a combustion head release model that used measured cylinder pressures and assumed spherical flame propagation. This flame speed was correlated with turbulent intensities measured in the motored engine. The ratio of fully developed turbulent flame speed to laminar flame speed was found to be a linear function of motored turbulent intensity. /GMRL/

Method and apparatus for reducing pollutant emissions while increasing efficiency of combustion

Abstract: A method and apparatus for reducing pollutant emissions from a source of combustion while simultaneously increasing the combustion efficiency. In a preferred mode, the technique contemplates the separation, removal and collection of positively charged species at the combustion zone. This is achieved by applying a relatively small magnitude electrostatic field at the combustion zone via positive and negative electrode means. A negative electrode may be positioned adjacent aperture means formed in the sidewall of the combustion chamber at the combustion zone so as to attract positive ionic species that include the pollutant emissions (e.g., NO + ) desired to be extracted. A negative electrode may also be electrically connected to a tube that serves to collect the pollutant for later processing to a useful by-product (e.g., nitrogenous fertilizer). Effective removal of the ionic species at the combustion zone permits combustion to occur at higher temperatures which, in turn, results in greater combustion efficiency.

Premix combustor assembly

Abstract: A combustor assembly having improved performance at low engine power operation and at altitude relight includes an annular combustion chamber, two fuel sources, and a premixing passageway having an outlet positioned adjacent either the inner and outer annular well of the combustion chamber. A perforated baffle is disposed across the outlet of the premixing passageway, the outlet being in gas communication with the combustion zone. In a preferred embodiment, for low power operation, such as for idle or for altitude relight, fuel from a first source is sprayed directly into the combustion zone. During this low power operation a localized stagnation region is created adjacent the fuel source which acts as a continuous ignition source for the combusting fuel-air mixture within the combustion zone. For high power operation such as takeoff, climb and cruise, fuel from a second source is injected into the premixing passageway where it is atomized by air entering the passageway from the compressor. During this high power operation the fuel-air mixture within the premixing passageway is directed into the combustion zone through the perforated baffle and radially across the combustion zone toward the opposite wall of the combustion chamber; the perforated baffle creates a localized stagnation region adjacent its surface which acts as a continuous ignition source for the combusting fuel-air mixture within the combustion zone during high power operation.

Burners for flame jet drill

Abstract: A burner in the form of a flame jet drill bit engine for liquid fuels is disclosed. The burner has particular utility in a flame jet drill and comprises an axially elongated body with a combustion chamber disposed therein. At least one flame jet nozzle is disposed through the body adjacent the bottom so as to communicate with the reaction chamber. At least one set of water or other liquid jet nozzles is also disposed on the bottom of the body which produce a pulsating water jet at extremely high velocities. The flame jet nozzle and the water jet nozzles are arranged and configured on the bottom of the body so as to be substantially parallel to the axis of the body. By the use of the combination of flame jets and water jets, a cutting means is produced which can cut through a wide range of amorphous and sedimentary rocks.

Gas-fired smooth top range

Abstract: A gas cooking range of the smooth top type has four burners positioned under a single plate of heat-resistant glass/ceramic material; and a single igniter and safety control assembly is centrally positioned between the burners The supply of gas to each of the burners flows through an ignition chamber where it is ignited, and it then flows through a combustion tube to a combustion chamber, where combustion is completed Some air is mixed with the gas at the fuel supply control valve, and additional air is supplied through the ignition chamber The burning gas mixture then flows through the combustion tube to the combustion chamber at the entrance of which an additional quantity of air is added to provide the remainder of air necessary for complete combustion Air is drawn into the system, and the products of combustion are exhausted by a blower positioned at the lower rear of the range so that a negative pressure condition is maintained along the entire path of flow of the fuel gas from the control valve and through the combustion chamber

Auxiliary power system and apparatus

Abstract: An auxiliary power system for an internal combustion engine The system employs a vapor or hot gas engine coupled to an internal combustion engine by means of an overruning clutch assembly The internal combustion engine, operated conventionally, generates heat in its cooling and exhaust systems as well as in accessory equipment The heat generated in the internal combustion engine and its accessories is used for generating vapor in one or more heat exchangers, the vapor preferably being from a liquid with a boiling point well below that of water The generated vapor is used to drive a vapor engine Temperature-sensitive means is employed to measure the heat generated in one or more parts of the system for controlling a linear solenoid valve for automatically controlling the internal combustion engine temperatures and thereby the amount of vapor generated A vacuum-controlled throttle valve is also employed in conjunction with the solenoid-operated valve for automatically controlling the input of vapor to the vapor engine for controlling its idle speed and for providing maximum acceleration as needed Safety valve means and vapor condensing means are provided at the output of the heat exchangers and steam engine to condense the generated vapor for recirculation in the system

Ultrasonic wave fuel injection and supply device

Abstract: An ultrasonic wave fuel injection and supply device includes an ultrasonic wave generating device and a fuel injection nozzle device. The ultrasonic wave generating device in turn includes an ultrasonic transformer, for transforming electrical oscillations into mechanical vibrations, connected to an ultrasonic oscillator, a mechanical vibration amplifier, for amplifying the amplitude of the mechanical vibrations, secured to the ultrasonic transformer, and a vibratory member, having a hollow cylindrically shaped body the peripheral wall of which is secured to the tip of the mechanical vibration amplifier with the axis of the vibratory member being disposed substantially perpendicular to the longitudinal axis of the mechanical vibration amplifier. The vibratory member has its opposite ends open and is disposed within an intake passage of an engine, the same therefore not hindering the flow of fluid through the intake passage. The fuel injection nozzle has its nozzle opening directed toward the peripheral wall of the vibratory member for injecting liquid fuel under pressure onto the peripheral wall. A fuel supply device introduces liquid fuel from a fuel reservoir to the injection nozzle, and a control device controls the amount of fuel being injected through the injection nozzle in response to the running conditions of the internal combustion engine. The ultrasonic wave fuel injection and supply device thus atomizes and scatters the liquid fuel injected onto the peripheral wall of the vibratory member as a result of the ultrasonic vibrations thereof, and the atomized and scattered liquid fuel is supplied to the combustion chamber of an engine, together with air from an air cleaner.

Catalytic premixing combustor

Abstract: This disclosure sets forth a combustion device for a power plant wherein a burner includes a central tubular section with an annular section located therearound. Air inlet means directs air to the burner. The central section comprises a premixing chamber and a combustion chamber for burning a fuel-air mixture while the annular section includes a catalytic reaction device. First tubular means directs air inwardly to said central tubular section for mixing with fuel where the fuel-air mixture is then burned. Additional air is added through second tubular means to the exhaust therefrom where it is then directed to one end of the annular section containing the catalytic reaction device. A transition member connects the exhaust end of the annular section to an outlet. Cooling louvers can be provided along this section if necessary. Further, a swirling device is located between the premixing chamber and combustion chamber for greater mixing of fuel and air.

Low nitric oxide emission combustion system for gas turbines

Abstract: Primary air to the fuel-air mixing chamber of a gas turbine engine is cooled to reduce generation of nitrous oxides. A porous disc separates the fuel-air mixture chamber from the combustion chamber and serves to uniformly mix the fuel and air to reduce the reaction temperature. A catalyst is sprayed on the disc surface in the combustion chamber to speed combustion. A heater embedded in the disc heats the disc and prevents excessive generation of nitrous oxides during the engine start-up. A metering valve can be used to regulate the temperature of the primary air by supplying heated secondary air to the primary air.

Method and apparatus for fuel injection-spark ignition system for an internal combustion engine

Abstract: Method and apparatus for providing improved combustion in an internal combustion engine by spark-ignition of fuel that is directly injected into cylinders to present a stratified fuel-air mixture at time of ignition. Reduced mixing of the fuel and air prior to ignition and thus greater stratification permits improved control of the combustion process to increase power and reduce pollutant emissions.

Two cycle internal combustion engines

Abstract: Crank-chamber precompression type two cycle engines having scavenging ports connected with the crank-chamber through scavenging passages. An air supply passage is connected through a reed type check valve with at least one of the scavenging passages at the upper portion thereof so that air is introduced into the scavenging passage in the ascending stroke of piston movement and discharged into the combustion chamber in the descending stroke of the piston movement to effect scavenging. The air passage is provided with a control valve which is interconnected with the engine throttle valve so that the amount of air supply through the air passage can be controlled in accordance with the load condition of the engine operation.

Ignition method and apparatus for internal combustion engine

Abstract: An internal combustion engine ignition apparatus includes a secondary spark plug having a center electrode to which a high voltage is applied. A cylindrical peripheral electrode surrounds the center electrode and has peripheral openings. Upon the formation of a corona discharge due to the high voltage applied to the center electrode, a strong ionic wind and convection of an air-fuel mixture are produced. The ionic wind causes fuel constituents to be gathered in the vicinity of the peripheral electrode thus preventing production of hydrocarbons due to cooling or quenching of the fuel on the combustion chamber wall. Initial ignition of the air-fuel mixture is by means of a main spark plug. The resultant flames are propagated to the corona discharge portion of the secondary spark plug. The corona discharge is then changed to secondary continuous spark discharge, to thereby positively fire the stratified air-fuel mixture. In another embodiment of the invention the auxiliary combustion chamber has a generally spherical configuration. The spherical auxiliary combustion chamber wall directs the extremely lean air-fuel mixture along a relatively long arcuate path back to outer side areas of the entrance to the auxiliary combustion chamber. The flow out of the auxiliary combustion chamber of the extremely lean air-fuel mixture from which fuel particles have been electrostatically precipitated, is further promoted by forming secondary openings in the wall of the auxiliary combustion chamber. The flow of the very lean air-fuel mixture to either the main or secondary openings in the wall of the auxiliary combustion chamber may be still further promoted by forming arcuate grooves on the inside of the auxiliary combustion chamber wall. The establishment of a corona discharge in either a main or auxiliary combustion chamber is promoted by forming a central electrode with a plurality of projections which extend toward a peripheral electrode which circumscribes the central electrode.

Fuel reformer for generating gaseous fuel containing hydrogen and/or carbon monoxide

Abstract: A reformer for obtaining a reformed gas containing H 2 and/or CO from an ordinary fuel exemplified by a petroleum fuel, having a reaction chamber in the form of a combustion chamber of a compression-ignition internal combustion engine, preferably with a swirl-producing auxiliary chamber, and a piston adapted to compress the fuel usually together with air at a compression ratio ranging from about 14 to about 20 in order to initiate and sustain a reforming reaction by the heat of adiabatic compression.

Variable compression ratio piston

Abstract: A two part variable compression ratio (VCR) piston assembly having an outer member movable relative to an inner member to vary the compression ratio of an internal combustion engine and a hydraulic system utilizing oil from the lubrication system of the engine for automatically controlling the relative movement of the members to maintain a predetermined maximum combustion chamber pressure A hydraulic circuit includes an upper and a lower chamber which expands and contracts conversely upon relative movement of the piston members and a system for supplying oil to the upper chamber and to the lower chamber via the upper chamber and for discharging the oil from the upper chamber in a manner which gradually changes the compression ratio of the piston until a predetermined maximum combustion chamber pressure has been achieved and which tends to maintain the maximum combustion chamber pressure after it has been achieved The lower chamber is disposed adjacent the piston ring area and a sealing ring is utilized as a valve for regulating oil flow from the upper chamber to the lower chamber

Fuel nozzle for gas turbines

Abstract: A fuel nozzle for use with gas turbines includes a centrally disposed orifice for discharging fuel into a combustion chamber. A first annular passage surrounds the fuel orifice and discharges primary air adjacent the exit of the fuel orifice for effecting atomization of the fuel and mixture of the air with the fuel to provide a fuel/air spray having a predetermined spray angle. A second annular passage for supplying secondary air is provided surrounding the first passage. This second passage is formed to supply air in a manner which creates a relatively low pressure substantially at the base of the fuel/air spray. When operating at the low fuel flow rates corresponding to low loads, air is supplied only through the first air passage and a relatively narrow spray angle, with a substantial concentration of fuel, is achieved. In a specific embodiment, as the load increases secondary air is supplied with a swirling motion through the second or outer annular passage and creates a vortex of rotating air flow, resulting in a reduction in static pressure at the base of the spray formed by the mixture of fuel and primary air. The reduction in pressure at the base of the spray causes the spray angle to be increased and enhances fuel and air mixing. This improves combustion and reduces smoke emission. In other embodiments, if desired, secondary air may be supplied at any fuel flow rate to provide the optimum spray angle for any given condition. The spray angle is controllable independently of the fuel flow rate.

Thin and low specific heat ceramic coating and method for increasing operating efficiency of internal combustion engines

Abstract: An internal combustion engine having combustion chamber walls coated with a thin ceramic coating with a specific heat of less than 0.12 BTU/lb/° F, a thermal conductivity of less than 11 BTU/HR/FT/° F and a thickness of 0.2 to 1 mil so as to reduce heat losses and increase efficiency of the engine.

Supersonic combustion ramjet /scramjet/ engine development in the United States

Abstract: This survey of supersonic combustion ramjet (scramjet) engine development in the United States covers development of this unique engine cycle from its inception in the early 1960's through the various programs currently being pursued and, in some instances, describing the future direction of the programs. These include developmental efforts supported by the U.S. Navy, National Aeronautics and Space Administration, and U.S. Air Force. Results of inlet, combustor, and nozzle component tests, free-jet engine tests, analytical techniques developed to analyze and predict component and engine performance, and flight-weight hardware development are presented. These results show that efficient scramjet propulsion is attainable in a variety of flight configurations with a variety of fuels. Since the scramjet is the most efficient engine cycle for hypersonic flight within the atmosphere, it should be given serious consideration in future propulsion schemes

Evaluation of Burned Gas Ratio (BGR) as a Predominant Factor to NOx

Abstract: Experiments were conducted with four cylinder production engines to evaluate the effect of EGR and mixture stoichiometry on NOx by measuring the burned gas ratio in the cylinder (BGR) by using a gas sampling valve and CO//2 gas analyzer. The total gas fuel ratio (G/F) in the cylinder, which is a function of air-fuel ratio (A/F) and BGR and is some measure of adiabatic combustion peak temperature of charge, was introduced as a new measure to evaluate the combustion in the cylinder. G/F ratio coupled with A/F could be utilized to evaluate the combustion characteristics such as NOx emission, misfire limit, etc. in various combustion chamber configurations. NOx emission and misfire limit are strongly affected by the BGR in the cylinder. Stoichiometrically burned gas EGR has the best potential to reduce NOx together with power for a fixed engine displacement, but from the point of view of fuel economy and misfire limit indicated by G/F, its mixture is the second to leanest A/F, when the critical constraint of NOx and better fuel economy were considered.

Heavy fuel oil nozzle

Abstract: An atomizing nozzle particularly suited for your use in compact combustion chambers Successful combustion of liquid fuels having generally high viscosity and widely varying properties such as distillation temperatures, distillation rates and impurities, including "heavy" and waste oil Improved combustion is accomplished through the use of viscosity control and improved fuel atomization Use of a nozzle utilizing "shearing" of the fuel by an atomizing fluid stream which intersects the fuel at approximately right angles Recombination of liquid fuel particles is prevented by the use of a controlled "exit orifice" in the burner nozzle The nozzle also features continuous circulation of the fuel in the nozzle body which establishes orientation of impurities contained in the fuel relative to the exit orifice so that they are expelled through the orifice Combustion of conventional distillate fuel oil such as API No 1 and 2 is also provided

Pulse combustion control system

Abstract: There is disclosed a safety control for a pulse combustion system. In a pulse combustion process, a combustible fuel and air are introduced into a combustion chamber through check valves in pulses and ignite to generate an alternating sinusoidal pressure wave. The control system of the invention comprises rectifying the sinusoidal pressure wave to obtain therefrom a differential pressure signal and applying the pressure signal to a control circuit to position a valve in the combustible fuel supply. Any interruption in combustion within the chamber causes a cessation of the differential pressure signal and closes the control valve. The apparatus of the invention includes, as the rectification facility, a dynamic check valve having a funnel member which is longitudinally disposed in a conduit communicating between the pulse combustion chamber and a pressure responsive transducer, the latter being operatively connected to maintain the fuel supply valve open during combustion and to close the fuel supply valve upon failure of combustion within the chamber.

Precombustion ionization device

Abstract: Precombustion ionization devices are disclosed for treating the vaporizable liquid fuel in internal combustion engines, including at least one foraminous member prepared from a catalytic metal having an oxide coating on the surface thereof. The foraminous member, or screen, is spaced from the carburetor and the engine intake of the internal combustion engine by means of a supporting gasket. The disclosed precombustion ionization devices may also be attached to a source of relatively high voltage, resulting in increased ionization of the vaporizable liquid fuel thereby, and preventing electropolishing of the metal oxide coating.

Circuit for controlling the operability of one or more cylinders of a multicylinder internal combustion engine

Abstract: Circuit for controlling the operability of one or more cylinders of a multicylinder internal combustion engine having electrically controllable means associated with it for preventing combustion from occurring in at least one cylinder of the engine. Preferably, the electrically controllable means for preventing combustion in a cylinder comprises a solenoid and associated mechanical means for preventing opening of the intake and exhaust valves for such cylinder to be thus disabled. Maintaining the intake and exhaust valves in a closed condition prevents the intake of an air-fuel mixture and permits compression and expansion, in a spring-like manner, of gases trapped within the combustion chamber. Electrical circuit means are provided for sensing a plurality of conditions of operation of the engine and logic circuit means, responsive to the sensing circuit means, are provided for controlling the actuation of the means for preventing combustion from occurring in the cylinder or cylinders selected for disablement.

Gas turbine combustion chamber arrangement

Abstract: A gas turbine has a combustion chamber of toroidal configuration that includes separation structure dividing the combustion chamber into an annular primary zone and an annular dilution zone. Injection of compressor discharge air into the primary zone sets up a toroidal recirculation pattern of generally circular cross-sectional configuration. Fuel slinger structure at the inner periphery of the primary zone has a generally cylindrical surface for receiving and distributing fuel in a thin sheet for discharge in a radially outward direction as minute droplets towards the center of the toroidal recirculation pattern. The radial flow of the fuel droplets interacts with said toroidal recirculation pattern and provides intimate mixing of fuel and air, and resulting efficient combustion within said primary zone. The resulting combustion product flows from the primary zone past the separation structure into the dilution zone. Compressor discharge air injected into the dilution zone dilutes the products of combustion from the primary zone.