Showing papers on "Ignition system published in 1976"

Spontaneous Ignition Delay of a Fuel Droplet in High Pressure and High Temperature Gaseous Environments

Abstract: Experimental and theoretical studies on the ignition delay of a single droplet in high pressure gaseous environments were carried out. In the experiments, a movable furnace was dropped over a droplet to cause the ignition and the measurement of ignition delay was made for normal paraffin hydrocarbon droplets at 0 atg40 atg of ambient gas pressure and 220°C700°C of ambient gas temperature. Experimental data were correlated with the following expression. [numerical formula] where P, T, and φd are pressure, and temperature and oxygen concentration of ambient gas of which increase makes the ignition delay short. Ignition delay was independent of droplet size and increased with an increase in the number of carbon atom in a molecule of fuel. In the theory, a model was developed for droplet ignition, which consisted of the evaporation of a droplet and ignition of homogeneous gas mixture, and ignition delay was calculated. Both the experimental and the theoretical results showed reasonable agreements.

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/

Radiative Ignition of Double Base Propellants: I. Some Formulation Effects

Abstract: In this first paper of a two part study, the ignition response to arc image radiative heating (5 to 100 cal/cm sec) of several double-base propellants is examined; comparisons with certain AP and HMX propellants are made also. Ignition delay is affected by chemical factors in propellant formulation (stability of the condensed phase, reaction rate in the gas phase) and by optical factors in propellant formulation (opacifiers affecting reflectivity and in-depth absorption). The results show that comparisons of the chemical factors in the formulation can only be made properly when the optical factors are minimized (as by carbon addition). When optical factors are minimized by opacifying the propellant, one finds, in order of increasing ease of ignitability, the formulations tested fall as follows: HMX composite, AP composite, double base (noncatalyzed), double base (catalyzed).

Dual mode solid state inverter circuit for starting and ballasting gas discharge lamps

Abstract: A variable frequency ac source drives a gas discharge lamp connected as a damping element in an otherwise high Q L-C circuit. Commutation of the ac source voltage is initiated as the instantaneous current drawn from the source equals a predetermined reference current level. Prior to lamp ignition the ac source drives the L-C circuit at resonance causing a voltage buildup which initiates an ignition. After ignition the source limits lamp current to provide a ballasting function.

Radiative Ignition of Double Base Propellants: II. Pre-ignition Events and Source Effects

Abstract: In this second paper of a two-part study, emphasis is on the pressure dependent pre-ignition events in double base propellants and the influence of radiation source (arc image vs laser) on observed ignition behavior. The pressure-dependent (< 21 atm) ignition domain of a PNC/MTN double base propellant is examined using controlled exposure lengths together with high speed movies and an infrared detector to monitor flame development. There is a brief flux-dependent period of transient flame development after gasification begins; this is followed by a relatively long, flux-dependent period of steady-state, radiation assisted burning before a selfsustaining condition is reached. The nature of this condition for self-sustainment is not yet well-defined. The ignition behavior seen with an arc furnace or a laser is generally quite close for both double base and composite propellants, if optical effects (reflection, penetration) are factored out. An exception is fast deradiation extinction, seen only with the laser; greater radiation penetration in the arc image wavelength region precludes this phenomenon. I. Introduction A S pointed out in the companion paper,l thermal zmradiation is a convenient energy input for studying solid propellant ignition behavior. By varying such factors as radiant flux, ambient pressure, and propellant compositions, much can be learned about the processes underlying the macroscopic ignition response, e.g., which of these factors controls that behavior in differing ambient conditions and what is needed to predict ignitability quantitatively in new circumstances. At the same time, one must be aware that the unique nature of radiation and the characteristics of the devices used to produce it can affect the test results. The present study is a systematic survey of radiation ignition behavior of a variety of propellants, intended to illustrate both these positive and negative aspects. In the companion paper,1 a generalized ignition behavior 4'map'* (log °f irradiation time vs log of radiant flux) was presented. The boundaries on this map were discerned by go/no-go testing and by monitoring of IR radiation from the developing flame. For clarity, we summarize them again here in the order they are encountered as irradiation time increases: Lla = first gas evolution; Llb = first IR signal from the surface region indicating the beginning of exothermicity; L]c = incipient flame indicated by a roughly 50-fold increase in IR signal; Lld = self -sustained flame indicated by steady burning if flux is removed; L2 = deradiation extinction boundary indicated by disappearance of a well-developed flame when radiation is removed too quickly. The companion paperl concentrated on certain propellant formulation effects; it illustrated how these boundaries are shifted strongly by the optical properties of the propellants. This was shown to obscure the comparison of different types of propellants, but unmodified double base propellants

Digital ignition spark timing angle control with read only memory

Abstract: A read only memory is pre-programmed to produce an output binary signal representation of a predetermined ignition spark timing angle based upon the instantaneous value of both of two selected engine operating parameters at each of a plurality of respective selected points within the range of values in response to respective input address signals. Over the range of values of the two selected engine operating parameters, therefore, the read only memory generates a three-dimensional surface of ignition spark timing angles. The binary signal representations of the ignition spark timing angles retrieved from the read only memory are varied in accordance with engine manifold vacuum and actual atmospheric pressure to tilt the three-dimensional surface generated by the read only memory about a selected engine parameter value as an axis in an amount substantially inversely proportional to actual atmospheric pressure.

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.

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

Method and apparatus to determine the timing of a periodically repetitive event with respect to the position of a rotating body, and more particularly ignition timing, fuel injection timing, and the like, in automotive internal combustion engines

Abstract: A pair of marker signals are generated with respect to a predetermined crankshaft position; the leading edge of the marker signal is used as a control edge to generate, by digital calculation, a digital control signal calculated in accordance with engine operating characteristics, as related to speed, loading, and the like, and providing a numerical output value used as a control value to control the timing of a pulse which may, depending on use, control: ignition timing; fuel injection timing; transmission gear shifting, the data relating engine performance, with respect to loading, speed, and other parameters such as temperature, starting conditions, and the like, being stored in a data memory. Calculation of the digital control signals and determination, by timed sequential counting out, are carried out independently from each other and during time overlap. Under starting, or emergency condition, an override can be provided coupling the trailing flank of the marker signal -- occurring, for example, at upper dead-center position of the cylinder -- to the output of the system to provide directly generated ignition pulses.

Liquid propellant weapon system

Abstract: A gun and ammunition system utilizing a round of ammunition which contains a supply of liquid propellant and after ignition pumps this propellant into the combustion chamber of the gun.

Pulse-actuated fuel-injection spark plug

Abstract: A replacement spark plug for reciprocating internal combustion engines that functions as a fuel injector and as a spark plug to provide a "stratified-charge" effect. The conventional carburetor is retained to supply the main fuel-air mixture which may be very lean because of the stratified charge. The replacement plug includes a cylindrical piezoelectric ceramic which contracts to act as a pump whenever an ignition pulse is applied to a central rod through the ceramic. The rod is hollow at its upper end for receiving fuel, it is tapered along its lower length to act as a pump, and it is flattened at its lower end to act as a valve for fuel injection from the pump into the cylinder. The rod also acts as the center electrode of the plug, with the spark jumping from the plug base to the lower end of the rod to thereby provide spark ignition that has inherent proper timing with the fuel injection.

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.

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.

Ignition timing control method and apparatus

Abstract: A method and apparatus for controlling the ignition timing in an internal combustion engine The angular position of peak cylinder pressure is measured and to the extent such angular position deviates from a preselected set point, the time of spark ignition is advanced or retarded to restore the position of peak cylinder pressure to the set point

Estimates on the ignition of high‐explosives by laser pulses

Abstract: The response of high‐explosive materials to laser pulses is examined using a one‐dimensional theory. Two distinct regimes of laser flux density I and pulse duration τp are identified, one concerned with a thermal initiation process and the other with an impulse or shock initiation process. For the thermal problem the competition between laser‐induced ablation and thermal runaway is explored, and analytical formulas are found for an ignition time t* and maximum useful laser flux density I*. When I is below I* thermal initiation by the laser pulse is predicted to occur after an exposure time t* (I), but the rapid removal of material by laser‐induced ablation can preclude this type of initiation when I exceeds I*. Values of I* are found to vary from 20 kW/cm2 for PETN to 0.05 kW/cm2 for TNT. The corresponding t* values are about 4 μs for PETN and 0.3 s for TNT. For decreasing flux densities I0 below I*, the ignition time t* increases approximately as I−1.80. For the impulse problem a self‐regulating‐ablation...

Characteristics of high-density tokamak ignition reactors

Abstract: We determine the parameters of a tokamak reactor plasma that attains ignition in the same regime of collisionality, νeiA/ωbe, as present-day Ohmic-heated tokamak plasmas. The 'collisional' regime is attractive because the presently observed confinement scaling, nτ ∝ n2, can be employed, and fusion power densities can be very large (~10 W/cm3). The use of Nb3Sn toroidal field coils and a plasma elongation 1. 5 are necessary to attain the high plasma density (n ≈ 5 × 1014 to 1015 cm−3) required for ignition in this low-temperature collisional regime.

Apparatus for removing an ignition key cylinder

Abstract: An apparatus for removing an ignition key or lock cylinder containing a shaft. A collet assembly which can grasp an ignition key cylinder or lock cylinder is also mounted on the shaft. An annulus is mounted on the collet assembly for maintaining a secure engagement on the ignition key cylinder and a casing is mounted over the collet assembly shaft and annulus.

PERFORMANCE AND NOx EMISSIONS MODELING OF A JET IGNITION PRECHAMBER STRATIFIED CHARGE ENGINE.

Abstract: The development of a cycle simulation model for the jet ignition prechamber stratified charge engine is described. Given the engine geometry, load, speed, air-fuel ratios and pressures and temperatures in the two intakes, flow ratio and a suitable combustion model, the cycle simulation predicts engine indicated efficiency and NO emissions. The relative importance of the parameters required to define the combustion model are then determined, and values for ignition delay and burn angle are obtained by matching predicted and measured pressure-time curves. The variation in combustion parameters with engine operating variables is then examined. Predicted and measured NO emissions are compared, and found to be in reasonable agreement over a wide range of engine operation. The relative contribution of the prechamber NO to total exhaust NO is then examined, and in the absence of EGR, found to be the major source of NO for overall air-fuel ratios leaner than 22:1.

Electronic distribution and control device for the ignition of internal combustion engines, particularly for motor vehicles

Abstract: An electronic distribution and control device for the ignition of internal combustion engines, particularly for motor vehicles, having a computer with which is combined an ignition advance system the said computer processing signals supplied by detectors of limit positions between which the ignition must occur as a function of the speed of rotation of the engine, and by at least one sensor of one of the operational parameters of the engine, which signals are then amplified and fed to voltage step-up coils to produce an ignition spark between the electrodes of at least one sparking plug.

Transistor ignition circuit

Abstract: The present invention discloses an ignition system for internal combustion engines. The ignition system is particularly applicable to such engines including a magneto. The ignition system includes a semi-conductor ignition circuit in which a first transistor has its collector-emitter conduction path connected in series with the primary winding of an ignition coil assembly. A resistor is connected between base and collector of the first transistor to permit it to conduct. A control circuit connected between the base of the first transistor and the primary winding, turns the first trnasistor off when it is desired to interrupt the primary winding current. The ignition system also includes a magneto ignition coil assembly which has a low inductance primary winding having a relatively low number of turns. The coil assemblies of the present invention are generally unsuitable for use with conventional mechanical breaker points.

Device for automatic control of electronic spark ignition advance for internal combustion engines

Abstract: Automatic control of spark advance in an electronic ignition system for an internal combustion engine is effected by using a first electromagnetic pick-up cooperating with a protuberance which is phase-displaced on a rotary part (flywheel) relative to top dead center by the maximum advance angle required, and a second pick-up which cooperates with peripheral teeth on the rotary part. Pulses from the second pick-up are counted during a predetermined interval (T) initiated by a pulse from the first pick-up to provide a count which is stored as a reference value representing the required spark advance angle, this stored reference value being subsequently compared with the number of pulses from the second pick-up counted with the commencement of the next pulse from the first pick-up to provide a spark-triggering pulse upon parity of the number of these subsequently counted pulses with the reference value.