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The downsizing of internal combustion engines to increase fuel economy leads to challenges in both obtaining ignition and stabilizing combustion at boosted intake pressures and high exhaust gas recirculation dilution conditions. The use of non-thermal plasma ignition technologies has shown promise as a means to more reliably ignite dilute charge mixtures at high pressures. Despite progress in fundamental research on this topic, both the capabilities and operation implications of emerging non-thermal plasma ignition technologies in internal combustion engine applications are not yet fully explored. In this work, we document the effects of using a corona discharge ignition system in a single cylinder gasoline direct injection research engine relative to using a traditional inductive spark ignition system under conditions associated with both naturally aspirated (8 bar BMEP) and boosted (20 bar BMEP) loads at moderate (2000 rpm) and high (4000 rpm) engine speeds.

This study presents the development of a new HCCI simulation methodology. The proposed method is based on the sequential coupling of CFD analysis prior to autoignition, followed by multi-zone chemical kinetics analysis of the combustion process during the closed valve period. The methodology is divided into three steps: 1) a 1-zone chemical kinetic model (Chemkin Pro) is used to determine either the intake conditions at IVC to achieve a desired ignition timing or the ignition timing corresponding with given IVC conditions, 2) the ignition timing and IVC conditions are used as input parameters in a CFD model (Fluent 6.3) to calculate the charge temperature profile and mass distribution prior to autoignition, and 3) the temperature profile and mass distribution are fed into a multi-zone chemical kinetic model (Chemkin Pro) to determine the main combustion characteristics.

This research investigates how the handling of mixing and heat transfer in a multi-zone kinetic solver affects the prediction of carbon monoxide and hydrocarbon emissions for simulations of HCCI engine combustion. A detailed kinetics multi-zone model is now more closely coordinated with the KIVA3V computational fluid dynamics code for simulation of the compression and expansion processes. The fluid mechanics is solved with high spatial and temporal resolution (40,000 cells). The chemistry is simulated with high temporal resolution, but low spatial resolution (20 computational zones). This paper presents comparison of simulation results using this enhanced multi-zone model to experimental data from an isooctane HCCI engine.

This research work has focused on measuring the effect of fuel/air mixing on performance and emissions for a homogeneous charge compression ignition engine running on propane. A laser instrument with a high-velocity extractive probe was used to obtain time-resolved measurements of the fuel concentration both at the intake manifold and from the cylinder for different levels of fuel-air mixing. Cylinder pressure and emissions measurements have been performed at these mixing levels. From the cylinder pressure measurements, the IMEP and peak cylinder pressure were found. The fuel-air mixing level was changed by adding the fuel into the intake system at different distances from the intake valve (40 cm and 120 cm away). It was found that at the intake manifold, the fuel and air were better mixed for the 120 cm fuel addition location than for the 40 cm location.

The dynamic stage of combustion - the intrinsic process for pushing the compression polytrope away from the expansion polytrope to generate the indicator work output of a piston engine - was studied to reveal the influence of the air/fuel ratio on the effectiveness with which the fuel was utilized. The results of tests carried out for this purpose, using a 12 liter diesel engine, were reported last year [SAE 1999-01-0517]. Presented here is an analytic interpretation of the data obtained for part-load operation at 1200 and 1800 rpm. A solution is thus provided for an inverse problem: deduction of information on the dynamic features of the exothermic process of combustion from measured pressure record. Provided thereby, in particular, is information on the effectiveness with which fuel was utilized in the course of this process - a parameter reflecting the effect of energy lost by heat transfer to the walls.

The refinement of heat release analysis stems from the recognition that a combustion system is intrinsically non-linear. Thus, as appropriate for such an entity, its properties are expressed in terms of a thermochemical phase (or state) space, of which the thermodynamic aspects are exposed on a so-called Le Chatelier diagram, providing the fundamental background for the development of micro-electronic control to attain the most effective utilization of fuel. Implementation of this method of approach is illustrated by the analysis of the exothermic process taking place in two typical internal combustion engines, spark-ignition and diesel.

This paper reviews the sources of externally radiated automotive piston engine and vehicle noise and describes them in detail. The effects of various design and operational characters on intensity and character of noise, noise measurement, and analysis and identifications procedures are given extensive examination. A summary of current research on the reduction of engine noise is presented.

This is a continuation of the presentation of thermodynamic properties of selected fuel-air mixtures in chart form, suitable for utilization in engine performance calculations. Methane and propane, representative of natural gas and LPG are the two fuels considered. Using these charts, comparisons are made between the performance to be expected with these gaseous fuels compared to octane, as representative of gasoline. Reduced engine power is predicted and this is confirmed by experience of other investigators.

A theoretical and experimental study was undertaken to establish whether or not parametric correlations could be satisfactorily applied to combustion of ammonia in gas turbine combustors. It was found that a usual parameter of the form I (Re)0.7 was satisfactory for establishing blowout limits in modeling. However, the attainable values of chemical loading I were at least an order of magnitude less than those attainable with hydrocarbon fuels.

A digital computer and special program were used, along with new thermodynamic data, to recalculate and extend the scope and range of the classic combustion gas charts of Hottel and co-workers. A series of hydrocarbon and nonhydrocarbon fuels was treated over a range of fuel-air ratios, with temperatures extended up to 7200 R and pressures up to 15,000 psia. This, the first paper of a series, incorporates the resulting charts for isooctane at four mixture ratios ranging from 20% lean to 40% rich. Auxiliary charts for inducted mixture properties determination and a set of sample calculations are also included.