Showing papers on "Spark (mathematics) published in 1990"

Putting a stop to surface ignition

Abstract: Surface ignition in internal combustion engines – where hot sport in the combustion chamber can cause fuel to ignite either before or after the normal spark ignition – is both inefficient and harmful to the engine. Detection usually involves the engine being modified in some way, but a promising noninvasive technique is to use the spark plug to detect the passage of flame 'front'. This novel technique has been demonstrated recently in several research laboratories including that of M swain and colleagues at the University of Miami 1989 J. Phys. E: Sci. Instrum. 22 838).

Self-tuning optimization of spark ignition automotive engines

Abstract: The use of self-tuning control concepts applied to the adaptive optimization of spark ignition angles of an automotive engine is described. In particular, it is shown how the concepts of self-adaptive control theory can be modified to allow their use in a continuous updating of the spark-angle map as a function of load and speed. Used in this manner, the self-tuner can account for in-service changes in engine characteristics, changes due to variations of ambient and operational conditions. In addition, self-adaptation allows the spark-controller algorithm to tune itself, so that the factory-generated spark map is precisely matched to the exact nature of each individual engine. The basic theory of self-tuning optimizers (also known as extremum controllers) is outlined, and their performance features are discussed with particular reference to their implementation in adaptive spark-timing systems. It is shown that the self-tuning extremum controller can be made robust even when the signal-to-noise ratio is less than one. >

Reverse rotation engine

Abstract: A reversing internal combustion engine has an ignition system controlled by a microprocessor which samples the magneto voltage output in order to make decisions concerning spark/timing. By suppressing the spark to allow the engine to slow down, and reapplying the spark at a suitable advance, reversal of the engine is effected from forward to reverse or reverse to forward.

Apparatus and methods for optical emission spectroscopy

Abstract: A spark generator suitable for use in an optical emission spectrometer, and capable of generating a spark in a spark gap formed between an electrode and a sample to be analyzed, comprises a generator for generating a current of programmable amplitude in the spark gap in each of a series of discrete time intervals. The spark generator according to the invention is advantageous when compared with conventional spark generators in that it enables a higher degree of choice and control in the form of the spark. In particular, it enables the amplitudes of various portions of the spark to be independently varied, thus permitting the shape of the spark to be tailored to the particular analysis being performed. Also described are methods of optical emission spectroscopy which make use of the advantageous properties of the spark generator.

Spark ignition timing control system for internal combustion engine adapted to mixture fuel of more than one individual fuels having mutually different combustion characteristics

Abstract: In order to accomplish aforementioned and other objects, a spark ignition timing control system, according to the present invention, is adapted to perform spark ignition timing control for an internal combustion engine combustioning a blended fuel, such as gasoline/alcohol mixture fuel. The control system performs MBT control by adjusting spark advance angle toward a maximum pressure point in feedback manner. The spark advance angle derived in MBT control is modified with a correction value derived on the combustion propagation speed which is variable depending upon blending ratio of one of the fuels in the blended fuel.

Optimization of Spark and ESD Propellant Sensitivity Tests. A review

Abstract: All cured propellants can pass small-scale spark sensitivity tests, yet some, generally involving larger propellant samples, are electrostatic discharge (ESD) sensitive. These tests fail to rank propellants because the test methods themselves are not optimized and frequently use instrumentation which does not indicate the energy transferred to the sample. For spark ignition of premixed combustible gases or fuel sprays in air, minimum energies are measured and considered thermochemical properties for a given fuel/air ratio, initial temperature and pressure, and for a spray, a given droplet size distribution. Obtaining such data requires monitoring the total energy discharged across the gap during the spark and parametric studies where gap length and spark duration are varied systematically to establish the true minimum (essential to hazard/risk analysis). Electrode geometry and tip design, as well as electrode material, are other important considerations. Present spark and ESD sensitivity tests used for solid propellants are reviewed in the context of methods more likely to provide meaningful initiation thresholds.

SPARK: a benchmark package for sparse computations

Abstract: As the diversity of novel architectures expands rapidly there is a growing interest in studying the behavior of these architectures for computations arising in different applications There has been significant efforts in evaluating the performance of supercomputers on typical dense computations, and several packages for this purpose have been developed, such as the Linpack benchmark, the Lawrence Livermore Loops, and the Los Alamos Kernels On the other hand there has been little effort put into evaluating the performance of these architectures on the more complicated and perhaps more important sparse computations In this paper a package is proposed to fill this gap Its goal is not only to evaluate the performance of supercomputers on sparse computations, but also to analyze the machine-algorithm interaction

Spark electrodes (ignition electrodes) in a spark plug with a front chamber

Abstract: A method and 2 different devices are proposed for constructing spark electrodes in a spark plug (1) with a front chamber (3) as well as a narrowed lower sub-chamber (4) with a flow behaviour in the form of eddies, by means of which the erosive and corrosive wear of the spark electrodes (7) and (8) is counteracted by the particularly economical use of noble-metal wires composed of metals or metal alloys from the platinum group and, in addition, the resistance to corrosive and erosive removal of the material of the spark electrodes (7) and (8) increases progressively with the life.

Programmed spark scatter for idle speed control

Abstract: In an idle speed control system for an engine of an automotive vehicle, a method of controlling the idle speed within an engine speed envelope of acceptable values by inversely varying the spark advance setting with respect to the closed loop fuel control system modulations.

Method and apparatus for controlling spark ignition in an internal combustion engine

Abstract: A method and apparatus for controlling spark reignition in an internal combustion engine based on the detected luminosity or pressure in the combustion chamber is provided. Only the luminosity or pressure measurement may be used as a basis for this control. This method and apparatus is also capable of providing same cycle control of spark reignition.

Apparatus and method for determining travel time of acoustic energy

Abstract: The disclosure is directed to a method and apparatus for more accurately determining the transit time of acoustic energy travel between a transmitter location and a receiver location. An electrode pair spark gap is provided at the transmitter location, and an acoustic receiver is provided at the receiver location. The spark-gap is energized to produce a spark by coupling an electrical potential across the electrode pair. The generation of a spark at the spark gap is sensed, and an initializing signal is generated in response thereto. A timer is initialized in response to the initializing signal. The receipt of acoustic energy from the spark is detected at the receiver location and a terminating signal is generated in response thereto. The timer is terminated in response to the terminating signal, and the time measured by the timer is indicative of the transit time of acoustic energy travel between the transmitter and receiver locations. In a preferred embodiment, the means for sensing the generation of a spark at the spark-gap is operative to sense a current coupled to the electrode pair.

Method and apparatus for controlling ignition timing for marine engine

Abstract: An apparatus for controlling an ignition timing for a marine engine has a temperature sensor for detecting a cold or warm-up state of the engine and for outputting an ON/OFF signal, and has an ignition timing controller for receiving the signal from the temperature sensor, for receiving signals representing an engine rotational speed and a throttle opening degree which are sent from other sensors, and for setting an optimum ignition timing. The ignition timing controller includes a spark advance control arrangement for setting the ignition timing to a state in which it is spark advanced by a predetermined angle when a cold signal from the tempera-ture sensor is input, a first spark delay control ar-rangement for immediately setting the ignition timing to a spark delay state when the engine rotational speed reaches an unshiftable rotational speed after completion of the operation of said spark advance, and a second spark delay control arrangement for immediately setting the ignition timing to the spark delay state when a warm-up signal is input from the temperature sensor.

Control system for controlling spark timing for engine

Abstract: A control system for controlling the timing for sparking an engine is adapted to retard a spark timing in a predetermined amount at the time of accelerating. An amount of retarding the spark timing at the time of accelerating is set to be gradually increased and then to be gradually decreased. The retarding amount at the time of accelerating is preferably changed in each spark cycle, namely, in each spark timing.

Spark device for internal combustion engines

Abstract: The spark device of the present invention includes a line of spaced apart conductor segments which have small spark gaps therebetween One end of the line of segments is connected to a source of electrical energy, and the other end is connected to ground Upon applying electrical energy to the line of segments, a plurality of sparks are emitted simultaneously at each of the spark gaps The device can be in the form of a conventional spark plug or can be embedded in a circular body mounted to the combustion engine as part of the gasket assembly

Procedure and equipment for optical spark-emission spectrometry

Abstract: of EP0398462In a procedure for optical spark-emission spectrometry in which a spark plasma of a sample is produced in a spark chamber and is evaluated by spectrum analysis using a spectral apparatus connected, in particular optically, to the spark chamber via a connection space, the connection space and the spark chamber having a protective gas continuously flowing through them during a spark process, a flushing pressure is built up in the gas system upstream of the spark chamber. The sudden release of this flushing pressure, for example, before the start of the subsequent spark process brings about a surge-like flow of the volume of flushing gas released in the spark chamber and, consequently, a complete removal of any burn-up residues or air components from the spark chamber. The gas flow can be interrrupted during the standby time. Equipment for carrying out the procedure comprises a spark chamber with an inlet for the flushing gas which can be sealed gastight by means of a shut-off device which can be opened suddenly.

Control system for controlling spark timing of engine

Abstract: A control system for controlling spark timing of the engine is to control the retarding of the spark timing at the time of accelerating in anticipation. The amount of retarding the spark timing at the time of accelerating is set larger when the torque converter is provided in a driving system of the engine than when no torque converter is provided. A preferred feature is such that the amount of retarding the spark timing at the time of accelerating is set so as to be decreased gradually from its given initial value and that the retarding of the spark timing is suspended when the retarding amount reaches a value smaller than a given reset value. Both the initial value and the reset value are set to be greater when the torque converter is equipped than those when no torque converter is equipped.

Measuring method for tool chip composition and tool chip polishing device

Abstract: PURPOSE:To predict the life of a diamond tool and to perform machining of good surface accuracy by detecting the light emission color, brightness, and light emission pattern of a spark and specifying the components and the amount of impurity in the material of a chip. CONSTITUTION:The chip 1 is held by a moving mechanism for adjusting the attitude and load against a polishing disk finely so as to polish a prescribed part of the chip blade edge. A detector 7 is equipped with an objective 4, a diffraction grating 5 for diffusing the light emission color of the spark spectrally, a linear image sensor 6 for detecting the wavelength range and brightness of the spectral light, and a two-dimensional image sensor 11 which forms an image of the spark separately by a half-mirror 10 and obtains the image for the image processing of the light emission pattern. Then the spark 3 emitted by friction light emission from the contact point between the chip 1 of the diamond tool and the polishing disk 2 where abrasive grains 9 are stuck is detected 7 and the detection signal is processed 8 and displayed.

Dynamical behavior of ions in a radio frequency spark ion source

Abstract: The dynamical behavior of ions in a radio frequency spark ion source as a consequence of residual voltage oscillations during spark breakdown has been studied. Calculation of ion trajectories in the spark box showed that the transmission of ions is dependent on the phase angle between the residual potential oscillation and the departure of an ion. The interval of transmitting phase angles decreases toward lower masses, representing a mass discrimination. INTRODUCTION