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The demand for more efficient vehicles is growing worldwide. A promising technology is the engine downsizing plus turbocharging applied to gasoline direct injection, GDI, engines. In parallel with this technology, the use of lean mixtures on engines can be an extra opportunity to reduce fuel consumption. An experimental investigation was performed on an engine dynamometer to study the impacts of lean mixtures on the performance of a GDI engine. It was used a GDI 1.4L with turbo engine with a programmable engine control unit (ECU) to optimize the calibration for different air fuel ratios. The Engine was calibrated for maximum spark advance limited by knocking. Combustion duration, mass fraction burned and other combustion parameters were calculated based on in-cylinder pressure curve data. The combustion variability was analyzed from 900 recorded engine cycle for each operating condition. Results show that the use of lean mixtures can lead engines to improved efficiency.

An experimental investigation was performed on an engine dynamometer to study in cylinder pressure curve and combustion parameters variability with ethanol addition. It was used a Flex-Fuel engine, 1.4 L, 4 cylinders, with a programmable engine control unit to optimize the calibration for different blends of Brazilian gasoline and hydrous ethanol. Engine was calibrated for maximum break torque limited by knocking. In-cylinder pressure was measured by using a pressure sensor installed on the spark plug and analyzed by a combustion data system. Combustion duration, mass fraction burned, indicated mean effective pressure (IMEP) and others were calculated based on in-cylinder pressure curve data. The combustion variability was analyzed from 300 recorded engine cycle for each operating condition. Results for some operating conditions indicated that ethanol addition can reduce combustion variability on a non linear pattern.

Exergy analysis is a valuable tool for new combustion engine technologies evaluation. By combining both first and second laws of thermodynamics, the availability content of a control system can be precisely calculated, and maximum available work can be determined. One of the main features of exergy evaluation is that it can be performed without knowledge of intrinsic working details of the device being tested. Compressed air vehicles have been studied in the latter years, and several commercial solutions are being developed. While each developer approaches the problem with a different setup, all must be constrained by the second-law analysis. In this paper, a theoretical exergy analysis is performed for the compressed air engine, and the exergy content is determined as a function of the storage pressure. The exergy density of a typical compressed air tank is compared to those of hydrocarbons.

Hydrogen is considered one of the cleanest solutions for sustainable mobility. This paper presents an overview of some of these applications, such as internal combustion engines, fuel cell application and also blends of hydrogen and natural gas. This paper addresses questions regarding hydrogen properties such as net heating value, flame speed, power density, range of flammability and ignition energy. Also, the paper will draw a comparison between H2 and fossil and biofuels, such as ethanol. Questions regarding storage conditions, emissions levels, Internal Combustion Engine (ICE) air/fuel ratio among others are expected to be covered as well.

On-board measurement is a powerful method to assess vehicular exhaust gas emission, since it enables the acquisition of instantaneous raw emission values in real-world conditions. While the vehicle emissions are subject to traffic and environment fluctuations, on-board measurement is a fast and economical way to generate data for fleet emission inventories, for instance. It is part of the mandatory testing for heavy-duty vehicles in the USA, as regulated by the USEPA. In 2004, Petrobras (Brazilian Oil Company) first experienced on-board emission measurements while participating in an international joint project, whose objective was to obtain information regarding the light-duty vehicular gas emission contribution to pollutant levels in some of the major Latin-American cities.