Automotive Gasoline Engine Research Articles

EFFECTS OF N ON CREEP PROPERTIES OF AUSTENI-TIC HEAT-RESISTANT CAST STEELS DEVELOPEDFOR EXHAUST COMPONENT APPLICATIONSAT 1000 ℃

To comply with more stringent environmental and fuel consumption regulations in recent years, automotive gasoline engines equipped with turbochargers are increasingly used to improve fuel efficiency. As a result, exhaust gas temperatures are now reaching 1050 °C, about 200 °C higher than the conventional temperature. Hence, there is an urgent demand in automobile industries to develop novel and economic austenitic heat-resistant *福特与中国大学合作研究资助项目 收到初稿日期: 2015-12-03,收到修改稿日期: 2016-03-03 作者简介:张银辉,男, 1985年生,博士生 DOI: 10.11900/0412.1961.2015.00618

Impact on Performance, Emissions and Thermal Behavior of a New Integrated Exhaust Manifold Cylinder Head Euro 6 Diesel Engine

The integration of the exhaust manifold in the engine cylinder head has received considerable attention in recent years for automotive gasoline engines, due to the proven benefits in: engine weight diminution, cost saving, reduced power enrichment, quicker engine and aftertreatment warm-up, improved packaging and simplification of the turbocharger installation. This design practice is still largely unknown in diesel engines because of the greater difficulties, caused by the more complex cylinder head layout, and the expected lower benefits, due to the absence of high-load enrichment. However, the need for improved engine thermomanagement and a quicker catalytic converter warm-up in efficient Euro 6 diesel engines is posing new challenges that an integrated exhaust manifold architecture could effectively address. A recently developed General Motors 1.6L Euro 6 diesel engine has been modified so that the intake and exhaust manifolds are integrated in the cylinder head. Extensive CAD/CAE/CAM analyses have been employed in order to guide the design of the overall surface and the water cooling jacket that surround the exhaust manifold of the new engine version, and thus to be able to improve the low-frequency thermal fatigue resistance of the head. The thus obtained prototype engine head has been tested on a highly-dynamic test bench at the Politecnico di Torino in order to characterize performance, emissions and thermal behavior in comparison to the baseline production engine. The results have generally been very promising and have shown the possibility of maintaining the same performance rating over the overall engine speed range as well as comparable emissions and brake specific fuel consumption in steady-state conditions. Furthermore, appreciably faster engine and aftertreatment warm-up have been recorded due to the higher heat fraction that is transferred to the coolant and to the more favorable exhaust gas enthalpy management. The latter benefit is in fact very interesting as far as the control of HC and CO emissions within the NEDC homologation is concerned

Rhenium- and ruthenium-containing catalysts for neutralization of automobile exhaust

The rhenium- and ruthenium-containing catalysts are active in the oxidation of CHx and CO and in the reduction of NOx. Comparative testing of catalyst samples under laboratory conditions and on an engine stand demonstrated that these catalysts outperform the known commercial catalysts in the neutralization of exhaust gas from automotive gasoline engines. It is, therefore, possible to completely replace expensive Rh and partially replace Pt and Pd with cheaper components—Re and Rh—in the manufacturing of catalytic converters.

Classification and individualization of used engine oils using elemental composition and discriminant analysis

The six most common commercial automotive gasoline and diesel engine oils in the Republic of Korea, ZIC A, ZIC XQ RV/SUV, Kixx G1, Kixx RV, and the brand name products HD Premium gasoline and HD Premium diesel, were randomly used in nineteen different vehicles. Samples of seventy-six used engine oils, which were withdrawn from the sumps of those vehicles at different intervals, were analyzed using inductively coupled plasma-optical emission spectrometry (ICP-OES), and statistically compared. Two data analysis strategies were used to interpret and understand the elemental profiles in the multi-dimensional data. Macro (additive elements of Ca, Zn and P) and trace (wear metal elements of Ag, Al, Ba, Cd, Cr, Cu, Fe, Mg, Mo, Na, Ni, Pb and Sn) elements were used as potential markers to determine the brand of oil used and the engine type in which the oil was used, and to trace the individual vehicle for forensic purposes. The discriminant analysis statistical technique was applied, and its prediction ability was assessed. In this study, 92.1%, 82.9% and 92.1% of the cross-validated grouped cases correctly predicted the brand of oil, the engine type and the vehicle that was the source of the oil, respectively.

Auto-digital gain balancing: a new detection scheme for high-speed chemical species tomography of minor constituents

In many dynamic gas-phase reaction processes, there is great interest to measure the distribution of minor constituents, i.e. <10−3 by volume (1000 ppm). One such case is the after-treatment of automotive gasoline engine exhaust by catalytic conversion, where a characteristic challenge is to image the distribution of 10 ppm (average) of carbon monoxide (CO) at 1000 frames per second across a 50 mm diameter exhaust pipe; this particular problem has been pursued as a case study. In this paper, we present a novel electronic scheme that achieves the required measurement of around 10−3 absorption with 10−4 precision at kHz bandwidth. This was not previously achievable with any known technology. We call the new scheme Auto-Digital Gain Balancing. It is amenable to replication for many simultaneous measurement channels, and it permits simultaneous measurement of multiple species, in some circumstances. Experimental demonstrations are presented in the near-infrared. In single scans of a tunable diode laser, measurements of both CO and CO2 have been made with 20 dB signal-to-noise ratio at peak absorption. This work paves the way for chemical species tomography of minor constituents in many dynamic gas-phase systems.

Robustness analysis of a Fourier-based strategy for cylinder-individual air–fuel ratio control

The paper investigates the robustness of a cylinder-to-cylinder air–fuel ratio controller that aims to reduce the exhaust emissions of automotive gasoline engines with spark ignition. A hardware configuration is considered where one wide-range sensor that measures the air–fuel ratio is mounted downstream of the confluence point of an exhaust manifold whose runners are linked to up to five cylinders. An uncertainty analysis is carried out for the closed-loop system with a controller based on Fourier analysis. First, a sensor non-linearity is modelled as an uncertainty and the robustness margins are investigated. With existing observers, the control loop can have a marginal robustness for systems with an even number of cylinders per sensor. For uneven cylinder numbers, however, the loop is always robust. The class of observers considered uses for reconstruction only the necessary number of spectral components of the sensor signal. A modified observer is proposed that also evaluates available redundant spectral information. As a result, the robustness is fully recovered for even numbers of cylinders and further improved for uneven numbers. The robustness is validated on an engine test-bench. Finally, a more complicated case of model uncertainty is investigated where the superimposing signals that originate from the individual cylinders are assumed to be uncertain.

Engine ignition signal diagnosis with Wavelet Packet Transform and Multi-class Least Squares Support Vector Machines

Engine ignition pattern analysis is one of the trouble-diagnosis methods for automotive gasoline engines. Based on the waveform of the ignition pattern, the mechanic guesses what may be the potential malfunctioning parts of an engine with his/her experience and handbooks. However, this manual diagnostic method is imprecise because many ignition patterns are very similar. Therefore, a diagnosis may need many trials to identify the malfunctioning parts. Meanwhile the mechanic needs to disassemble and assemble the engine parts for verification. To tackle this problem, Wavelet Packet Transform (WPT) is firstly employed to extract the features of the ignition pattern. With the extracted features, a statistics over the frequency subbands of the pattern can then be produced, which can be used by Multi-class Least Squares S upport Vector Machines (MCLS-SVM) for engine fault classification. With the newly proposed classification system, the number of diagnostic trials can be reduced. Besides, MCLS-SVM is also compared with a typical classification method, Multi-layer Perceptron (MLP). Experimental results show that MCLS-SVM produces higher diagnostic accuracy than MLP.

Method of improving the performance of gasoline engine work with internal mixing

Analyzes the problematic issues associated with the prospect of development of domestic automotive gasoline engines with internal mixing, which stimulate the need for search tools and new technical solutions that are acceptable for domestic engines. Noted the unacceptability of a direct copying of foreign decisions in domestic practice, not only because of the high financial costs for their implementation, but given the lack of technology and the necessary materials for their production. As an alternative, we propose a method that allows for minimal financial costs quickly solve an actual problem of domestic engine - the creation of the Russian automotive gasoline engine of a new generation with internal mixing. The method is based on the use of hydrogen as a chemical reagent that promotes improvement of ecological and economic qualities of the engine.

Investigation of the kinetic mechanism of nitrogen oxidation in an automotive engine with stratified mixing

The authors proposed the method of calculation, which allows to determine the local formation of nitrogen oxides in the combustion chamber of automotive gasoline engine with internal mixture formation for the modes with laminar organization of the charge. Heterogeneity of sharply stratified mixture the workspace of the combustion chamber is divided on the path of the flame propagation into areas with different (localized) air-fuel ratio. For Volkswagen AUX-type engine test calculations conducted, which results revealed that outcome of nitrogen oxides from the combustion of a stratified mixture is 2,2 times reduced in comparison with the traditional version of uniform homogeneous mixture. Discrepancy between calculated and experimental results does not exceed 8%, thus confirming the adequacy of a satisfactory calculation method.

A trial of ignition innovation of gasoline engine by nanosecond pulsed low temperature plasma ignition

Application of nanosecond pulsed low temperature plasma as an ignition technique for automotive gasoline engines, which require a discharge under conditions of high back pressure, has been studied experimentally using a single-cylinder engine. The nanosecond pulsed plasma refers to the transient (non-equilibrated) phase of a plasma before the formation of an arc discharge; it was obtained by applying a high voltage with a nanosecond pulse (FWHM of approximately 80 or 25 ns) between coaxial cylindrical electrodes. It was confirmed that nanosecond pulsed plasma can form a volumetric multi-channel streamer discharge at an energy consumption of 60 mJ cycle−1 under a high back pressure of 1400 kPa. It was found that the initial combustion period was shortened compared with the conventional spark ignition. The initial flame visualization suggested that the nanosecond pulsed plasma ignition results in the formation of a spatially dispersed initial flame kernel at a position of high electric field strength around the central electrode. It was observed that the electric field strength in the air gap between the coaxial cylindrical electrodes was increased further by applying a shorter pulse. It was also clarified that the shorter pulse improved ignitability even further.

Effects of oil properties on spark-ignition gasoline engine friction

The effects of base oil, friction modifier (FM) and viscosity grade on firing engine friction are investigated in an automotive gasoline engine. Unique aspects of the study are (1) viscosity grade is maintained when synthetic and conventional base oils are compared, (2) the influence of engine operating condition on the effectiveness of base oil, FM and viscosity grade in reducing engine friction is considered, and (3) friction-relevant design details of the test engine are discussed. Results show that replacing conventional oil with synthetic oil of the same viscosity grade reduces friction, especially at high boundary friction conditions. Molybdenum dithiocarbamate (MoDTC), and to a lesser extent organic FM, also reduce friction, especially at high boundary friction conditions. Furthermore, using 5W-20 oil causes less friction than 5W-30 and 10W-40 oil at both high and low boundary friction conditions. Results are expected to hold true for engines with similar friction-relevant designs.

Oxygen-Enriched Combustion of the First Cycle During Cold Start in a Liquefied Petroleum Gas Spark-Ignition Engine

The first firing cycle is very important for cold-start. Misfire of the first firing cycle can lead to significant hydrocarbon (HC) emissions and affect the subsequent cycles. Research has proved that the oxygen-enriched intake air (OEA) method is a useful technique to reduce cold-phase HC and carbon monoxide (CO) emissions from automotive gasoline engines. However, few researchers have studied oxygen-enriched combustion characteristics based on the first firing cycle analysis during cold-start. The present paper presents a comparison of atmospheric air with OEA in the combustion of the first cycle during cold-start in a liquefied petroleum gas spark-ignition engine. Cylinder pressure, engine speed, HC, CO, and nitric oxide (NO) emissions were collected. The heat release rate of atmospheric air and OEA combustion are calculated. Test results show that atmospheric air and OEA have similar high transients in HC emissions at cold-start. However, OEA reduces CO emissions and increases NO emissions. Comparing the heat release rate curves, oxygen-enriched combustion can lead to heat release earlier and higher than normal air combustion.

LaFePdO3 Perovskite Automotive Catalyst Having a Self‐Regenerative Function.

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Turbocharger-Design Effects on Gasoline-Engine Performance

Specification of a turbocharger for a given engine involves matching the turbocharger performance characteristics with those of the piston engine. Theoretical considerations of matching turbocharger pressure ratio and mass flow with engine mass flow and power permits designers to approach a series of potential turbochargers suitable for the engine. Ultimately, the final choice among several candidate turbochargers is made by tests. In this paper two types of steady-flow experiments are used to match three different turbochargers to an automotive turbocharged-intercooled gasoline engine. The first set of tests measures the steady-flow performance of the compressors and turbines of the three turbochargers. The second set of tests measures the steady-flow design-point and off-design-point engine performance with each turbocharger. The test results show the design-point and off-design-point performance of the overall thermodynamic cycle, and this is used to identify which turbocharger is suitable for different types of engine duties.

LaFePdO 3 perovskite automotive catalyst having a self-regenerative function

An automotive gasoline engine is operated close to the stoichiometric air-to-fuel ratio to convert the pollutant emissions simultaneously, accompanying with redox (reduction and oxidation) fluctuations in exhaust-gas composition through adjusting the air-to-fuel ratio. An innovative LaFe 0.95Pd 0.05O 3 perovskite catalyst, named ‘the intelligent catalyst’, has been developed, and which has a new self-regenerative function of the precious metal in the inherent fluctuations of automotive exhaust-gas. The LaFe 0.95Pd 0.05O 3 perovskite catalyst, La located at the A-site, was prepared by the alkoxide method. Pd located at the B-site of the perovskite lattice in the oxidative atmosphere, and segregated out to form small metallic particles in the reductive atmosphere. The catalyst retained a predominantly perovskite structure throughout a redox cycle of the exhaust-gas, while the local structure around Pd could be changed in a completely reversible manner. The agglomeration and growth of Pd particles is suppressed, even under the severe environment, as a result of the movement between inside and outside the perovskite lattice. It is revealed that the self-regenerative function of Pd occurs even at 200 °C, unexpectedly low temperature, in the LaFe 0.95Pd 0.05O 3 catalyst. Since the high catalytic activity is maintained, the great reduction of Pd loading has been achieved. The intelligent catalyst is expected as a new application of the rare earth, and then the technology is expected in the same way in the global standard of the catalyst designing.

Adaptive Fuelling of the SI Engine

The paper presents some investigations concerning implementation of the adaptive control methods for the control of the fuel injection in an automotive gasoline engine. As quality index the difference between a current emission level and the level obtained during the stoichiometric combustion was chosen. Stoichiometric mixture provides maximal conversion ratio of the catalytic converter. The paper presents mathematical procedures of the direct adaptive control, based on the adaptive algorithms, which use competitive estimators. Theoretical analysis was supplied with the results of computer simulation of the single point gasoline injection engine model.

Speciated hydrocarbon emissions and the associated local ozone production from an automotive gasoline engine

Concentrations of total and individual exhaust gas hydrocarbon species were measured from a contemporary automotive gasoline engine to gain insight into how an engine's operating conditions affect the combustion and post-flame oxidation processes and to estimate the ozone-forming potential of these hydrocarbons. Both the customary method of estimating maximum ozone production using maximum incremental reactivity (MIR) factors and a new method of estimating actual local ozone production (LOP) were used to quantify the harmfulness of the exhaust hydrocarbons. Depending on local atmospheric conditions, LOP estimations are about 2–10 times less than the method of maximum ozone production using MIR factors. Per unit of engine output, retarded spark timing and higher engine load reduce the LOP of catalyst-in hydrocarbons, while the air-fuel ratio does not strongly affect the LOP of catalyst-in hydrocarbons. LOP is increased during a start-up and drastically decreased by the catalytic converter, once the catalyst is heated to its operating temperature and the engine is run at stoichiometry.

The Value of Remanufactured Engines: Life‐Cycle Environmental and Economic Perspectives

Remanufacturing restores used automotive engines to like‐new condition, providing engines that are functionally equivalent to a new engine at much lower environmental and economic costs than the manufacture of a new engine. A life‐cycle assessment (LCA) model was developed to investigate the energy savings and pollution prevention that are achieved in the United States through remanufacturing a midsized automotive gasoline engine compared to an original equipment manufacturer manufacturing a new one. A typical full‐service machine shop, which is representative of 55% of the engine remanufacturers in the United States, was inventoried, and three scenarios for part replacement were analyzed. The life‐cycle model showed that the remanufactured engine could be produced with 68% to 83% less energy and 73% to 87% fewer carbon dioxide emissions. The life‐cycle model showed significant savings for other air emissions as well, with 48% to 88% carbon monoxide (CO) reductions, 72% to 85% nitrogen oxide (NOx) reductions, 71% to 84% sulfur oxide (SOx) reductions, and 50% to 61% nonmethane hydrocarbon reductions. Raw material consumption was reduced by 26% to 90%, and solid waste generation was reduced by 65% to 88%. The comparison of environmental burdens is accompanied by an economic survey of suppliers of new and remanufactured automotive engines showing a price difference for the consumer of between 30% and 53% for the remanufactured engine, with the greatest savings realized when the remanufactured engine is purchased directly from the remanufacturer.

A Study on Adsorber Substrate to Reduce Exhaust HC from a Gasoline Engine (Adsorption and Desorption Characteristics with Composition and Preparation of Zeolite).

Exhaust gas temperatures of automotive gasoline engines are not high enough for 3-way-catalyst to activate at the engine cold start conditions. As the results, unburned hydrocarbons of high concentration are emitted to the atmosphere without being oxidized. This study was conducted to investigate the characteristics of HC adsorber using zeolite to store HC just after cold start condition and purify later when gas temperature rises. Experiments using model gas test apparatus, engine bench test stand and chassis dynamometer were performed to examine the adsorption and desorption performance of adsorber substrate. The effects on the performance of ion exchanging with zeolite, the species of zeolites, the silica alumina ratio, binder species inside the coated layer in the honeycomb substrate were measured. The influence of the volume of the adsorber substrate and the thermal durability were also investigated.

Detailed Analysis of Oil Transport in the Piston Assembly of a Gasoline Engine

More realistic and useful models of piston ring lubrication can only be achieved if there is a better understanding of the complex mechanisms by which oil flows in this region of the engine. The volume of oil in the piston assembly and its residence time in this high-temperature environment are crucial in determining the quantity and quality of oil available to lubricate the piston rings. Typically models of piston ring pack lubrication focus upon the oil flowing through the piston ring/cylinder interface. However, a number of additional oil flow paths and interactions with gas blow-by have been observed in the piston assembly. This paper presents a model that includes a number of such mechanisms and evaluates their influence on the lubrication of a piston ring pack from a typical automotive gasoline engine. The results indicate that such additional mechanisms are needed to give improved predictions of oil transport they highlight the relative importance of several of these mechanisms and help guide future research.