Showing papers on "Spark (mathematics) published in 1996"

Ignition Control by Ionization Current Interpretation

Abstract: Spark advance setting in spark-ignited engines is used to place the in-cylinder pressure curve relative to the top dead center It is demonstrated that ionization current interpretation is feasible

Method and apparatus for controllably generating sparks in an ignition system or the like

Abstract: An apparatus for controllably generating sparks is provided. The apparatus includes a spark generating device; at least two output stages connected to the spark generating device; means for charging energy storage devices in the output stages and at least partially isolating each of the energy storage devices from the energy storage devices of the other output stages; and, a logic circuit for selectively triggering the output stages to generate a spark. Each of the output stages preferably includes: (1) an energy storage device to store the energy; (2) a controlled switch for selectively discharging the energy storage device; and (3) a network for transferring the energy discharged by the energy storage device to the spark generating device. In accordance with one aspect of the invention, the logic circuit, which is connected to the controlled switches of the output stages, can be configured to fire the stages at different times, in different orders, and/or in different combinations to provide the spark generating device with output pulses having substantially any desired waveshape and energy level to thereby produce a spark having substantially any desired energy level and plume shape at the spark generating device to suit any application.

The evolution of spark discharges in gases: II. Numerical solution of one-dimensional models

Abstract: Two different one-dimensional models describing the evolution of sparking in air are solved numerically using the artificial viscosity method and a flux-corrected transport algorithm. The influence of the solution technique, especially the treatment of the shock wave, is studied. The breakdown stage of the spark is included in the initial conditions. The electrical energy input is calculated from a prescribed current waveform coupled to the calculation of plasma conductivity. The effect of varying power input on the evolution of the plasma kernel is studied. It is shown that shock wave reflection from a rigid wall close to the spark gap influences the growth of the plasma kernel. The results indicate that the Eulerian description of motion can be used to model flow with shock waves with accuracy equal to that of the Lagrangian description.

Duration of the Resistive Phase and Inductance of Spark Channels

Abstract: The following is a brief resume of the formulae used for the resistive phase of a hot spark channel and some other comments relating to spark channels formed under various conditions.

Internal teeth spark erosion appts.

Abstract: In an appts. for spark eroding internally toothed workpieces (as described in DE application number 4324271), the electrode is a copy of the hollow workpiece interior and has the shape of an externally toothed gear wheel which is subjected to pilgrim step oscillatory motion.

Condition monitoring and fault diagnosis in a domestic car engine using a neural network

Abstract: The use of microelectronics in motor vehicle technology is well established, although a relatively recent innovation in comparison with the lengthy history of the motor car. In the automobile engine, the spark plug is in direct contact with the combustion processes and examination of the time varying voltage due to the spark ignition system at the spark plug provides a robust method of monitoring the engine. It has been shown that this waveform, subjected to neural network analysis, forms a mechanism which allows the monitoring of the engine for fault diagnosis or control. The technique potentially provides a convenient method of accurately sensing the /spl lambda/ of the engine. An investigation by the author and fellow researchers to demonstrate the feasibility of the technique has been described previously (R.J. Howlett et al., 1996); a summary of this work to date is presented.

In-Cylinder Diagnostics for Production Spark Ignition Engines

Abstract: A comprehensive review of diagnostic techniques for the study of in-cylinder phenomena in unmodified spark ignition engines is presented. The scope of the techniques considered is restricted to those that can be used without machining modifications to the engine. Thus, most of the diagnostics discussed are either integral with the spark plug or head gasket, or use the spark plug hole to study pre-ignition phenomena under motored operation. Among the more important instruments discussed are pressure sensors, ionization probes, luminosity detectors, gas sampling devices and gas velocity probes.

Method of adjusting idle spark for an individual cylinder of an internal combustion engine

Abstract: A method of adjusting idle spark for an individual cylinder of an internal combustion engine in an automotive vehicle including the steps of determining a crankshaft acceleration for an individual cylinder of the internal combustion engine and determining an average acceleration error for the individual cylinder based on the determined crankshaft acceleration. The method also includes the steps of determining an adaptive spark advance for the individual cylinder based on the determined average acceleration error and determining a new spark advance for the individual cylinder based on the determined adaptive spark advance and a nominal spark advance. The method further includes the steps of adjusting idle spark for the individual cylinder based on the new spark advance for the individual cylinder.

Method for advanced crank spark with blend spark retard for an engine

Abstract: A method for advanced crank spark with blend spark retard for an internal combustion engine includes the steps of selecting whether a spark in an engine cylinder will be fired on a normal or an advanced crank reference edge during an engine start mode, firing the spark on the advanced crank reference edge during the engine start mode if the advanced crank reference edge is selected, firing the spark on the normal crank reference edge if the normal crank reference edge is selected, checking if an engine speed is greater than a predetermined number of revolutions per minute (RPM), continuing to select whether to fire the spark on the normal crank reference edge or the advanced crank reference edge if the engine speed is less than the predetermined RPM, and retarding the spark from a first spark level to a hold start level at a predetermined rate, holding the spark at the hold spark level for a hold period, and advancing the spark to the first spark level at the predetermined rate, if the engine speed is greater than the predetermined RPM

Modern Spectrochemical Analysis of Metals: An Introduction for Users of Arc-Spark Instrumentation

Abstract: An Introduction for Users of Arc/Spark Instrumentation. This book is a fundamental introduction to the increasingly important field of spectroscopy. Designed for both beginning and experienced users of arc/spark spectrometer it provides the vital background necessary to fully understand the instrumentation. As an added help, most terms are completely defined when they're first used in the text. Numerous examples and figures are utilized to illustrate the main points. You'll also find most equations and formulas come with sample calculations to show actual usage. Examples of authentic data from spectrochemical analysis of selected metals can be found throughout this valuable reference source. Contents include: Chemistry and Physics, Instrumentation Basics of the Spectrometer, Calibration for Spark Spectrochemical Analysis, Statistical Analysis for Precision and Accuracy, Instrument Operation, Quality Control, Applications, Various Selected Topics.

I-D simulation of a spark discharge in air

Abstract: The development and radial expansion of a spark is simulated using a finite element method. The caleulations start from a weakly conducting channel as left by the passage of a streamer. Plasma heating during break down is provided by an L-C combination resembling the equivalent circuit of the spark plug. Once the effective current provided by this circuit drops below a certain level, a current source with a linearly decreasing current with time was used to model the subsequent arc or glow phases. The simulations cover a time range from nanoseconds up to 10 μs, when the axial symmetry of the channel is broken by 2-D effects such as reverse gas flow along the electrodes. It is shown that equivalent plasma kernels can be produced by assuming initial conditions where the breakdown energy is deposited within a very small cylindrical volume of ambient mass density. This also causes the emission of a strong shock which is indispensable for the achievement of same shape of the kernel. Calculations for ambient pressure and temperature as well as for 5 bar/550 K were conducted. The influence of the breakdown energy, the radiation, and the current delivered by the current source on the fully evolved spark channel is discussed. It is suggested how to use the calculated thermodynamic properties of the plasma kernel as initial conditions for flame-kernel calculations using a chemical reaction scheme. The fluid-mechanical Euler equations, including thermal conductivity, radiation losses, and Joule heating, are implemented using a Taylor-Galerkin formalism. The electric field is calculated using a time-independent potential formulation. This is implemented in the frame of the finite element program Flux Expert (Flux Expert is a registered trademark of DT2i).

Burst knock prevention at high engine load

Abstract: The present invention provides an apparatus for limiting the occurrence of knock conditions in an internal combustion engine. The apparatus includes a throttle sensor that detects transition of an engine throttle from a steady state throttle condition to a wide open throttle condition. Further, spark means is provided for generating a spark for an engine cylinder firing event, with the spark means generating the spark with an associated spark advance. Further, a controller is provided that is responsive to the wide open throttle condition detected by the throttle sensor and that causes the spark advance to incrementally advance to a maximum level over a predetermined time period, thereby minimizing the occurrence of engine knock conditions.

Control device for vehicle engine and automatic transmission

Abstract: PURPOSE: To provide a control device preventing the running performance of a vehicle from being reduced even if the spark delay control on the cylinder group presently being used is infeasible when at least one of multiple cylinder groups is operated for a travel. CONSTITUTION: When the spark delay control on the cylinder group being operated is judged to be infeasible by a spark delay feasibility judging means 138 during the partial cylinder group operation travel of an engine 10, the operation of the cylinder group being operated is stopped and the other cylinder group is operated by a cylinder group forced switching means 140. When the catalyst of the exhaust system of the other cylinder group is used, the spark delay control of the engine 10 can be continuously performed at the time of the speed change of an automatic transmission 14, and the partial cylinder group operation can be continued. The improvement effect of fuel consumption is secured, the spark delay control by a spark delay control means 136 at the time of speed change can be continued, the speed change shock preventing effect is secured, and the running performance of a vehicle is maintained.

Pestov Spark Counter prototype development for the CERN-LHC ALICE experiment

Abstract: A prototype Pestov Spark Counter with two-dimensional position resolution has been developed. The position resolution is 0.32 mm and

Modeling and simulation of spark ignition engines

Abstract: Modeling is important because it saves time, effort and cost needed for engine development and prediction of performance. In this work, losses due to imperfect construction of the real engine, including progressive combustion, valve timing and heat transfer have been modeled besides engine friction. Hence, it becomes possible to convert the output of the fuel-air cycle into net brake performance. Simulation of engine performance was carried out by varying engine speed, compression ratio and spark advance over wide range. Hence, it was possible to compare the results with those from experiments on a single cylinder engine. The model predictions were found to compare favourably with experiment within 4·6% in power and 2·9% in SFC. The losses considered in this work amount to about 14% of the fuel energy input.

Inductive pickup sensor with enhanced cross-talk immunity

Abstract: An inductive pickup sensor employing an isolation transformer to achieve substantially improved immunity to capacitively-induced cross-talk signals is provided A magnetic pickup coil is coupled to a spark plug wire to receive a spark signal The spark signal developed across the magnetic pickup coil is then coupled to via a sensor cable to the primary winding of an isolation transformer which is configured to provide a relatively low interwinding capacitance level to substantially reduce the cross-talk signal amplitude relative to the spark signal at a detector circuit The detector turns the spark signal into a trigger signal at a pair of output terminals

Spark plug ignited engine analyzing device and method

Abstract: An engine analyzing device for an internal combustion engine including a spark generator and means for testing the voltage of the sparks generated for a diagnosis of engine performance, the testing of the sparks generated relating to analysis of the spark voltage wave form from the breakdown voltage, the collapsing field voltage and the duration of the spark pulse or some combination of these.