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N-butanol and isobutanol are alcohols that can be produced from biomass by fermentation and are possibly more compatible with existing engines than ethanol. This work reports on the effects of these two isomers on exhaust emissions of an unmodified direct injection spark ignition (DISI) engine. A Ford Focus car with a 1.0-liter Euro 6 Ecoboost DISI engine has been tested on a chassis dynamometer using WLTP and Artemis driving cycles, and on the road on a one-hour test loop containing urban, rural and motorway driving. Two isomers of butanol, 1-butanol and 2-methyl-propanol, were each blended with gasoline at 25% volume. Non-oxygenated gasoline and 15% ethanol in gasoline (E15) were used as reference fuels. The vehicle performed well in terms of cold start, drivability, general performance, and off-cycle particle emissions, staying within several mg of particle mass and about 2×1012 particles (per PMP procedure) per km during laboratory tests.

This contribution is focused on an investigation of two well-known techniques, i.e. the modified Atkinson working cycle with a late intake valve closing (LIVC) and the Miller working cycle with an extreme early intake valve closing (EIVC) in order to increase the fuel economy of a throttled SI engine at a part load (high throttled mode). However, the application of the Atkinson and Miller cycle causes a decrease in the in-cylinder charge temperature before the compression stroke. In the case of a constant value of the geometric compression ratio, the in-cylinder charge temperature at the beginning of the combustion is also decreased and the combustion is then slower (compared to a standard Otto cycle). This could negatively influence the indicated efficiency of the unconventional cycle. In order to avoid this, increase in the in-cylinder charge temperature was provided due to mixture heating in the intake manifold of the engine.

In certain applications, the use of natural gas can be beneficial when compared to conventional road transportation fuels. Benefits include fuel diversification and CO₂ reduction, allowing future emissions regulations to be met. The use of natural gas in vehicles will also help to prepare the fuel and service infrastructure for future transition to gaseous renewable fuels. The composition of natural gas varies depending on its source, and engine manufacturers must be able to account for these differences. In order to achieve highly fuel flexible engines, the influence of fuel composition on engine properties must first be assessed. This demand is especially important for engines with high power densities. This paper summarizes knowledge acquired from engine dynamometer tests for different compositions of natural gas. Various levels of hydrocarbons and hydrogen in a mixture with methane have been tested at full load and various engine speeds.

The paper describes a simple simulation tool for determination of vehicle energy consumption under dynamic conditions, suitable for early stages of design and linked to other tools being developed inside Vehicle concepts modeling (VECOM) project framework. The simulation tool is based on ordinary differential equations and a dynamic expandable library of vehicle component features. It describes vehicle dynamics in longitudinal direction and the appropriate efficiencies of engine, transmission and accumulation components (if used). All required data may be obtained by targeted simulations using multi-dimensional methods or by experiments. The simplified algorithms finding the best usage of powertrain chain efficiency in dependence on required pre-defined operation conditions (real driving record or a driving test cycle) were established.

The presented work deals with an accurate method for the EGR (Exhaust Gas Recirculation) rate determination, which is suitable for the real combustion engines equipped with the uncooled EGR system. A Thermal Balance method (further T.B.) has been proposed for this purpose. It uses differences between EGR (hot gas) and fresh charging air temperatures as a base for the EGR mass fraction determination. This method has been developed and tested on a real engine in authors' laboratory and verified using the well known CO2 method. As it is known that this method is inherently not accurate, the paper deals with a possibility how to improve the method. Measured differences between results from both methods T.B. and CO2 are within 8% in the measured operating range.