A Study of Injector Deposits, Combustion Chamber Deposits (CCD) and Intake Valve Deposits (IVD) in Direct Injection Spark Ignition (DISI) Engines II

Based on the mathematical validated by experimental data, the present paper introduces the evolution of concentration and velocity fields of Liquefield Petroleum Gas (LPG) jet in combustion chamber of spark ingnition enegine under effects of injection conditions and surrounding environment. The results allow us to predict the development of jet for an efficient organization of mixture preparation and combustion process in LPG direct injection spark ignition engine

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Effect of Combustion Chamber Shape on In-Cylinder Flow and Air-Fuel Interaction in a Direct Injection Spark Ignition Engine - A CFD Analysis

10.4271/2015-26-0179 ◽

2015 ◽

Cited By ~ 1

Author(s):

Ballapu Harshavardhan ◽

J M Mallikarjuna

Keyword(s):

Combustion Chamber ◽

Direct Injection ◽

Spark Ignition ◽

Spark Ignition Engine ◽

Cfd Analysis ◽

Direct Injection Spark Ignition ◽

Cylinder Flow

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Experimental investigation of combustion and heat transfer in a direct-injection spark ignition engine via instantaneous combustion chamber surface temperature measurements

Proceedings of the Institution of Mechanical Engineers Part D Journal of Automobile Engineering ◽

10.1243/09544070jauto853 ◽

2008 ◽

Vol 222 (11) ◽

pp. 2219-2233 ◽

Cited By ~ 14

Author(s):

K-W Cho ◽

D Assanis ◽

Z Filipi ◽

G Szekely ◽

P Najt ◽

...

Keyword(s):

Heat Transfer ◽

Heat Flux ◽

Surface Temperature ◽

Combustion Chamber ◽

Direct Injection ◽

Local Heat ◽

Spark Ignition ◽

Heat Fluxes ◽

Instantaneous Combustion ◽

Direct Injection Spark Ignition

An experimental study was performed to provide the combustion and in-cylinder heat transfer characteristics resulting from different injection strategies in a direct-injection spark ignition (DISI) engine. Fast-response thermocouples were embedded in the piston top and cylinder head surface to measure the instantaneous combustion chamber surface temperature and heat flux, thus providing critical information about the combustion characteristics and a thorough understanding of the heat transfer process. Two distinctive operating modes, homogeneous and stratified, were considered and their effect on combustion and heat transfer in a DISI engine was investigated. The stratified operating mode yielded significantly higher spatial variations of heat flux than the homogeneous mode. This behaviour is directly caused by the main features of stratified combustion, i.e. vigorous burning of a close-to-stoichiometric mixture near the spark, and a cool, extremely lean mixture at the periphery. The cooling effect of the spray impinging on the piston surface when the fuel is injected late in compression could be detected too. The local phenomena change with varying speed and injection parameters. Comparison between the calculated global heat fluxes and measured local heat fluxes were performed in order to assess the behaviour of classic heat transfer models. Comparisons between the global and local heat fluxes provide additional insight into spatial variations, as well as indications about the suitability of different classic models for investigations of the heat transfer aspect of DISI engines. Special consideration is required when applying classic heat transfer correlations to stratified DISI operation as heat flux values are lower by more than 30 per cent when compared with homogeneous operation of the same engine at the same load.

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Prediction of gaseous pollutant emissions from a spark-ignition direct-injection engine with gas-exchange simulation

International Journal of Engine Research ◽

10.1177/14680874211005053 ◽

2021 ◽

pp. 146808742110050

Author(s):

Stefania Esposito ◽

Lutz Diekhoff ◽

Stefan Pischinger

Keyword(s):

Gas Exchange ◽

Combustion Chamber ◽

Direct Injection ◽

Spark Ignition ◽

Operating Conditions ◽

Pollutant Emissions ◽

Operating Parameters ◽

Gaseous Pollutant ◽

Fuel Ratio ◽

No Emissions

With the further tightening of emission regulations and the introduction of real driving emission tests (RDE), the simulative prediction of emissions is becoming increasingly important for the development of future low-emission internal combustion engines. In this context, gas-exchange simulation can be used as a powerful tool for the evaluation of new design concepts. However, the simplified description of the combustion chamber can make the prediction of complex in-cylinder phenomena like emission formation quite challenging. The present work focuses on the prediction of gaseous pollutants from a spark-ignition (SI) direct injection (DI) engine with 1D–0D gas-exchange simulations. The accuracy of the simulative prediction regarding gaseous pollutant emissions is assessed based on the comparison with measurement data obtained with a research single cylinder engine (SCE). Multiple variations of engine operating parameters – for example, load, speed, air-to-fuel ratio, valve timing – are taken into account to verify the predictivity of the simulation toward changing engine operating conditions. Regarding the unburned hydrocarbon (HC) emissions, phenomenological models are used to estimate the contribution of the piston top-land crevice as well as flame wall-quenching and oil-film fuel adsorption-desorption mechanisms. Regarding CO and NO emissions, multiple approaches to describe the burned zone kinetics in combination with a two-zone 0D combustion chamber model are evaluated. In particular, calculations with reduced reaction kinetics are compared with simplified kinetic descriptions. At engine warm operation, the HC models show an accuracy mainly within 20%. The predictions for the NO emissions follow the trend of the measurements with changing engine operating parameters and all modeled results are mainly within ±20%. Regarding CO emissions, the simplified kinetic models are not capable to predict CO at stoichiometric conditions with errors below 30%. With the usage of a reduced kinetic mechanism, a better prediction capability of CO at stoichiometric air-to-fuel ratio could be achieved.

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