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It is known that the levels of hydrocarbon (HC) emissions from Homogeneous Charge Compression Ignition (HCCI) engines are relatively higher than that of Spark-Ignition (SI) engines because of the lower combustion temperature. In order to improve understanding of the mechanisms and products of HCCI combustion in comparison with SI combustion, a quantitative analysis of individual hydrocarbons in the C1 - C6 range emitted in the exhaust gases of gasoline direct injection V6 engine operating in SI and HCCI modes with cam profile switching has been carried out using gas chromatography - mass spectrometry (GCMS) apparatus attached on-line to engine exhaust. In this study, with a GC run time of 20 minutes all aliphatic and olefinic hydrocarbon species in the range C1 to C6 are resolved.

Increasing biodiesel content in mineral diesel is being promoted considerably for road transportation in Europe. With positive benefits in terms of net CO2 emissions, biofuels with compatible properties to those of conventional diesel are increasingly being used in combustion engines. In comparison to standard diesel fuel, the near zero sulphur content and low levels of aromatic compounds in biodiesel fuel can have a profound effect not only on combustion characteristics but on engine-out emissions as well. This paper presents analysis of particulate matter (PM) emissions from a turbo-charged, common rail direct injection (DI) V6 Jaguar engine operating with an RME (rapeseed methyl ester) biodiesel blended with ultra low sulphur diesel (ULSD) fuel (B30 - 30% of RME by volume). Three different engine load and speed conditions were selected for the test and no modifications were made to the engine hardware or engine management system (EMS) calibration.

Producing on-board the hydrogen that is to be used as supplementary fuel by exhaust gas reforming of gasoline shows encouraging results. Extensive research has been done at the University of Birmingham towards on board generation of hydrogen-rich gaseous fuel. Exhaust gas reforming which utilizes water vapor and enthalpy from the hot engine exhaust gas was applied using a compact system of a fuel reformer reactor integrated with the three way catalytic converter (TWC). Such system can be fitted in the limited space close to the engine. The device has been designed and built in concentric shape with the catalytic converter as a core and the reformer in an annular shape outside, to best utilize the waste heat from the catalytic converter. It requires very little extra space beyond the baseline catalytic converter.

Previous work of the authors' group has shown that biodiesel fuels as a replacement for conventional diesel fuel in engine combustion can reduce PM level dramatically while lowering some other regulated emissions as well. It has shown that these fuels have the potential to increase the overall engine performance due to their lower sulphur and/or aromatics content compared with standard diesel fuels. This paper presents a study on a single cylinder naturally aspirated direct injection (DI) diesel engine, equipped with a pump-line-nozzle injection system, operating with varied biodiesel fuel blends (0%, 25%, and 50% of RME by volume) with ultra low sulphur diesel fuel (ULSD). The detailed analysis of the measurement data shows that the ignition delay and exhaust emissions are affected by the proportion of biodiesel due to the effect of different physical and chemical properties of the two fuels.

The airflow around an idealized wheel has been modelled using Star-CD 3.1, a commercial CFD package, and measured in a wind tunnel fitted with a moving ground. Measurements were made of the static pressure along the centreline of the idealised wheel and of the vortex characteristics immediately behind the wheel. Flow characteristics have been shown to change significantly with the introduction of wheel rotation, wheel width, and exposure to the oncoming flow. The CFD model successfully predicted the main features of the pressure profile around the wheel using the RNG k-ε turbulence model with the QUICK higher-order differencing scheme and the log-law wall function. The size of the vortex pair immediately behind the wheel and the Cp profile along the centreline of the wheel were found to be dependant upon the width of the wheel and the exposure to the oncoming flow.

This paper describes the development of an interactive model to simulate a direct injection diesel engine under both steady and transient conditions, based on the application of concurrent process computing methods. Initially the engine is modelled operating under steady conditions and induction, injection, air entrainment, fuel air mixing, combustion, emission and the mechanical friction processes are considered. The fuel pump, governor, engine crankshaft and external load dynamics are incorporated in the model to study the transient behaviour of a 2.5 litre D. I. engine and its associated load. Employing a two zone combustion model enables detailed performance and exhaust emissions predictions to be produced with economic use of computing time. The model written in FORTRAN is implemented in parallel on a transputer based concurrent computer by using the transputer operating system language OCCAM as a harness. Model predictions compare favourably with experimental results.