Showing papers on "Spark (mathematics) published in 1995"

From Spark Ignition to Flame Initiation

Abstract: The process of spark ignition and the subsequent flame propagation in an internal combustion engine have been investigated. A unique theoretical model which considers the various physical and chemical phenomena associated with the ignition process has been developed. It employs a two-dimensional cylindrical coordinate system and assumes axial and radial symmetry. The model employs also a detailed chemical reaction scheme for a methane-air mixture which contains 29 chemical species and 97 reactions. The thermodynamic and transport properties are evaluated by using statistical thermodynamics and molecular theory approach while including the various energy modes stored in the mixture particles. The appropriate conservation equations are solved numerically by using an integration of the PHOENICS and the CHEMKIN codes. It was concluded from the numerical results that the spark kernel growth can be described as a two-step process. The early short stage (1–5 μs), which involves a pressure wave emission,...

Feedback linearization of spark-ignition engines with continuously variable transmissions

Abstract: Replacing conventional gear-boxes with continuously variable transmissions (CVT's) can reduce the fuel-consumption of spark ignition engines significantly. A possible approach to the control of this type of drive-train structures for a specific operating condition ("high-power regime") is discussed in this paper. In the first part the plant dynamics are exactly linearized over the complete operating range using feedback linearization. Much attention is paid to the existence conditions for this nonlinear part. In the second part, as an application of the exact linearization approach, a "kick-down"-controller is designed. Simulations show that combining the two controllers yields good transient behavior and robustness of the closed-loop system. >

Engine with flow coupled spark discharge

Abstract: An improved spark ignition engine system producing a large continuous, centrally directed, flow coupled ignition spark discharge through combustion chamber (1), piston (4), inlet system (28/29), spark plug (5), and ignition spark discharge (26) design, and through the location and orientation, with respect to the mixture flow field, of a special design firing end and gap (7/9) of a spark plug fired with a spark discharge of hundreds of watts of power for hundreds of microseconds without spark segmentation or spark break-up by the flow field of up to about 20 m/sec flow velocity, with bulk flow occurring at the spark plug site at most engine speeds including low speeds to produce a very large centrally directed spark-initial flame front kernel which allows for substantial dilution of the mixture and significant reduction in engine cycle-to-cycle variation under most operating conditions of the engine including low speed light load.

Spark Anemometry of Bulk Gas Velocity at the Plug Gap of a Firing Engine

Abstract: The objective of the present work was to investigate a rapid method of obtaining the convection velocity of the bulk gas near the spark plug gap of a firing engine at the time of ignition. To accomplish this, a simple model was developed which utilized both the secondary current and voltage signals, from a conventional spark discharge. The model assumed the spark path was elongated in a rectangular U-shape by the flow. Based on experimentally measured electrical signals, the mean convection velocity was computed. The convection velocity calculated by the model first needed calibration which was accomplished with a bench test that used a hot wire anemometer. The technique has a weak correlation at low velocities of 1--2 m/s, but correlates well as higher velocities up to 15 m/s. Although the accuracy of prediction by the technique is moderate, it is shown to be suitable for rapidly studying the bulk flow velocity ear the plug gap in an operating engine without modification of the combustion system. It is also shown to favorably compare with data taken with a fiber optic equipped spark plug.

Multi fire spark plug

Abstract: A spark plug for an internal combustion engine having one or more electrode diagonally projecting from a central electrode into a V-shaped grounding window which is cut into the skirt of the spark plug body. The novel electrode suspended in the grounding window provides broader spark dispersion, through a wider arching area, and greatly improved spark plug life.

Misfire detection in a spark ignition engine

Abstract: A method for detecting misfire in a cylinder of an internal combustion engine through the ignition system of the engine. The present invention first predicts a time-to-fire measurement for an interrogating spark, then measures the actual time-to-fire measurement of the interrogating spark and then compares the predicted measurement and the actual measurement to determine whether misfire has occurred.

Spark ignition system of an internal combustion engine

Abstract: A spark ignition system of an internal combustion engine has a plurality of electrodes operating at high voltages to produce a plurality of sparks across the combustion zone The construction of the system permits the formation of long length sparks while substantially maintain the utilization of customary electrical wiring sizes

Spark Heat Transfer Measurements in Flowing Gases

Abstract: Using a technique based on holographic interferometry, the total energy transferred from a spark to the surrounding gases was measured for a number of spark plug electrode geometries, flow velocities, gas pressures and coil charge times. A standard automotive ignition coil was used. For the combinations of parameter values studied, we observed spark efficiencies(ratio of the energy in the gas heated by the spark to the electrical energy supplied to the spark plug) of from 20 to 60 percent. For realistic engine conditions we estimate the quantity of energy transferred to the gas by our ignition system to be roughly 30 mJ. We show how these measurements of total energy transferred to the gas can be used to estimate the spark power vs. time characteristic of a standard inductive ignition system.

The 4d9−4d8(4f + 6p) transitions of In V

Abstract: The spectrum of indium was photographed from 200 to 450 A on 3-m and 10.7-m grazing-incidence spectrographs with sliding spark and triggered spark light sources. With the aid of Hartree-Fock calculations 116 lines in the region 223-265 A were interpreted as 4d9−4d8(4f + 6p) transitions of In V. Parametric least-squares-fitting calculations were carried out to fit the energy parameters to the observed energy levels.

Method for monitoring operations of an internal combustion engine to detect combustion misses

Abstract: A method is proposed for monitoring operations of an internal combustion engine to detect combustion misses for internal combustion engines having dual spark coils. A method is provided for the primary-side monitoring of the spark voltage and/or of the spark duration, and a method is provided for detecting irregular operations. If a faulty ignition is detected in one cylinder at one spark plug by monitoring the spark voltage and/or the spark duration, the second spark plug in this cylinder is then cut off (de-energized) and the reaction to this cut-off is monitored by means of the method for detecting irregular running. If the irregular running detection confirms faulty operation of the internal combustion engine, then the faulty ignition at the first spark plug of a cylinder was correctly recognized and appropriate emergency measures are introduced.

Magneto with Dual Mode Operation

Abstract: An ignition system is provided for an internal combustion engine (67) that operates in two modes. In a first mode, the timing of the spark event is under electronic control. In a second mode, the timing of the spark event is fixed and synchronized to the mechanical rotation of the crankshaft (65) of the engine. Under normal operating conditions, the timing of the spark event is electronically controlled. If the electrical system of the engine malfunctions, the ignition system defaults to the second mode in which ignition timing is mechanically controlled.

Engine ignition control

Abstract: A spark advance system for an internal combustion engine having a conventional throttle operated spark advance that provides a spark advance related to load. In addition, an arrangement is provided for using an alternate spark timing during start-up so as to provide optimum spark timing under start-up conditions.

Methods for Ionization Current Interpretation to be Used in Ignition Control

Abstract: It is desirable to measure engine performance for several reasons, e.g. when computing the spark advance setting in spark-ignited (SI) engines. There exists two methods, among others, of measuring ...

Oxidation of hydrocarbons desorbed from the lubricant oil in spark ignition engines

Abstract: in Spark Ignition Engines by Michael G. Norris B. S., Mechanical Engineering Oregon State University, 1985 S.M., Mechanical Engineering Massachusetts Institute of Technology, 1991 Submitted to the Department of Mechanical Engineering in Partial Fulfillment of the Requirements for the Degrees of Doctor of Philosophy at the Massachusetts Institute of Technology; September 1995 © 1995 Massachusetts Institute of Technology. All rights reserved.

Digitally controlled magneto ignition system with alternate timing

Abstract: A digitally controlled magneto provides for the precise control of the timing advance profile for an internal combustion engine. A micro-controller or a micro-processor provides the digital control by using inputs from engine sensors to determine the engine's crank speed and position. With this information, it computes an optimum timing advance angle for the time of spark generation. The digital system controls the spark generation by using a semiconductor switching circuit to interrupt the flow of current generated by the magneto in the primary coil. The current flow interruption results in a high voltage pulse in the secondary coil creating a spark in a spark gap for the initiation of combustion in the internal combustion engine. To maintain the operational reliability of the magneto ignition system, an alternate timing system allows the internal combustion engine to produce full power even if the electrical power supplied to the digital system fails. The invention succeeds in improving the efficiency of the internal combustion engine while maintaining its operational reliability. An increase in efficiency has the advantage of both reducing the engine's toxic exhaust emissions and its specific fuel consumption rate.

Process for monitoring of reference cylinder for spark-ignition internal combustion engine

Abstract: The process for monitoring the combustion phase involves measuring the voltage at the terminals of the spark plug (5) in the reference cylinder to determine the combustion phase. The change with time of the potential at the spark plug terminals is tracked, and the appearance of the high tension pulse generating the spark identified. The stage in the cycle is identified from the measured high tension value. The information is used to control timing of fuel injection and advance or retard of ignition. The monitoring, processing and control of injection and ignition are performed by a suitably programmed computer (7). The timing signal for the controller is derived from a variable reluctance transducer (4) fitted to the engine flywheel.

Advanced automotive ignition systems

Abstract: Spark ignition engines utilize ignition systems that can develop up to about 30 kV for breakdown of the spark plug gap and typically deliver current levels in the range of 30 to 100 mA. Measurement and analysis of these systems show that the energy transfer efficiency is very low, typically in the order of one percent (1%) or less. This operating level is adequate for older and most modern engines, but will not meet the needs of future lean burn and some alternate fuel engines that require higher energy discharges to effectively ignite the air/fuel mixtures. To meet the requirements for increased ignition power and energy, ignition systems will have to be designed to operate at higher transfer efficiencies. There are two basic approaches to increasing the electrical efficiency of ignition systems. The first is to utilize peaking capacitors across the spark plug. The second is to design and utilize a more efficient discharge circuit in combination with a low resistance spark coil. A third alternative would be to utilize a combination of both. By the first method, transfer efficiency can be increased to nearly fifty percent (50%). By the third, transfer efficiency can be seventy-five percent (75%) or more. This paper summarizes the results of high power ignition experiments and related analyses, for so-called "breakdown ignition" conditions. The paper includes descriptions of both conventional system up-grades and a new higher energy system that features multiple drivers and an energy recovery circuit. It does not include analyses or experiments for arc or glow discharge conditions.

Device of estimating heat resistivity for a spark plug and a method of estimating the same

Abstract: In a device of estimating heat resistivity for a spark plug, an ignition spark control circuit is provided to discontinue ignition spark across electrodes of a spark plug at a predetermined intervals. A counter circuit is provided to count the times of the ignition spark suppressed by the ignition spark control circuit. A self-ignition detection circuit is provided to detect the self-ignition from the spark plug when the ignition spark is suppressed by the ignition spark control circuit. A self-ignition counter circuit is provided to count the numbers of the self-ignition detected by the self-ignition detection circuit. A calculation circuit is provided to calculate occurrences rate of the self-ignition from the spark plug on the basis of the suppressing numbers of the ignition spark counted by the counter circuit and the detecting numbers of the self-ignition counted by self-ignition counter circuit. A self-ignition timing detection circuit is provided to detect a detection timing of the self-ignition detected by the self-ignition detection circuit. A preignition timing anticipating circuit is provide to anticipate an ignition timing when preignition of the internal combustion engine occurs on the basis of the occurrence rate of the self-ignition detected by the calculation circuit and detecting timing of the self-ignition detected by the self-ignition timing detection circuit.

Spark plug test instrument

Abstract: The utility model relates to a spark plug test device for ignition operating conditions, which can quickly judge the spark plug with failure and can detect the actual reason which causes the failure without disassembly of the spark plug and any parts while an internal combustion engine works. The test device is composed of a circuit part composed of a rotating speed measuring unit, a cylinder selecting and setting unit, a discharging time measuring unit, a spark line voltage measuring unit and an ignition quality test and fault diagnosis unit, a shell body, a panel, etc. The utility model has the advantages of simple structure and convenient operation, and is the real time tool of the site for automobile maintenance, failure removal and the acceptance check of automobiles.