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Environmental issues and energy security are critical concerns of the most countries. According researchers, excessive growth of land vehicles is one of the biggest contributors to global air pollution and oil reserves reduction. In this context, the use of lean burn technologies emerges as a promising strategy, allowing lower fuel consumption and pollutants emissions. Present work aims to analyze the behavior of a current commercial engine, gasoline fueled, varying the air-fuel ratio without the use of lean burn ignitions technologies. Analysis was performed through bench dynamometer tests, evaluating cylinder pressure, exhaust gas temperature, fuel conversion efficiency, cycle thermal efficiency, coefficient of variation in indicated mean effective pressure, apparent heat release rate, flame development angle and burn duration.

Environmental policies and fuel costs have driven the development of new technologies for internal combustion engines. In this sense, the use of mixtures with small portions of fuel allows lower fuel consumption and pollutants emissions, emerging as a promising strategy. Despite the advantages, lean burn requires a larger energy source to provide satisfactory flame propagation speed and consequently a stable combustion. The use of pre-chamber ignition systems (PCIS) has been used in SI engines to assist the start of combustion of lean mixtures, in which a supplementary fuel system can stratify the amount of either liquid or gaseous fuels supplied to the pre-chamber. In this context, this paper aims to evaluate combustion characteristics of a commercial engine with the use of stratified PCIS operating with impoverished mixtures of ethanol-air in main-chamber and hydrogen assistance in pre-chamber.

The trends in the development of spark ignition engines leads to the adoption of lean mixtures in the combustion chamber. Torch ignition systems have potential to reduce simultaneously the NOx and CO emissions, while keeping the fuel conversion efficiency at a high level. This study aims to design and analyze a torch ignition system running with ethanol on lean homogeneous charge, adapted to an Otto cycle single-cylinder engine with optical visualization. The main objective is to achieve combustion stability under lean burn operation and to expand the flammability limit for increasing engine efficiency by means of redesigning the ignition system adapting a pre-chamber to the main combustion chamber. Experiments were conducted at constant speed (1000 rpm) using ethanol (E100) as fuel, for a wide range of injection, ignition and mixture formation parameters. Specific fuel consumption and combustion stability were evaluated at each excess air ratio.

One of the principal goals of modern vehicle control systems is to ensure passenger safety during dangerous maneuvers. Their effectiveness relies on providing appropriate parameter inputs. Tire-road contact forces are among the most important because they provide helpful information that could be used to mitigate vehicle instabilities. Unfortunately, measuring these forces requires expensive instrumentation and is not suitable for commercial vehicles. Thus, accurately estimating them is a crucial task. In this work, two estimation approaches are compared, an observer method and a neural network learning technique. Both predict the lateral and longitudinal tire-road contact forces. The observer approach takes into account system nonlinearities and estimates the stochastic states by using an extended Kalman filter technique to perform data fusion based on the popular bicycle model.

This work presents a full analysis of a bi-fuel engine converted to natural gas and aims to survey the main performance losses and the advantages in specific consumption and toxic emissions. With this purpose, dynamometric tests and curves survey of a Fiat Palio 1.6, 16V engine, according to Standard NBR ISO 1585. Tests were made using diverse mixers, trying to obtain the losses caused by this device when the engine is working with gasoline, after the conversion. Tests were performed for different ignition advances, with manual and electronic VNG flow control systems. Trials for many differents low gear engine regulation, looking for consumption reduction and lower emission rates. The gas pressure reducer was tested with and without heating, showing differents results, mainly for emission rates. Other than comparing different components and different engine operation conditions, an analysis of two different natural gas conversion kits were performed, both extensile used in Brazil.

The present study introduces a proposal to improve the longitudinal performance of a land vehicle through the adoption of an unusual traction control system. The system is capable of improving the transfer of engine power to the ground and reduces the complexity of the task being performed by the driver. High-performance vehicles are able to achieve high levels of longitudinal acceleration and, sometimes, the power excess leads to the spinoff of the drive wheels, which decrease the ability of the tires to generate force, and consequently the vehicle acceleration. The proposed system acts in addition with the motor control, through the derivation of the motor speed signal, and its control by comparison with a predefined value. The control can delay or even suppress the ignition of the engine. Thus, the rate at which the engine gains speed, and consequently, the rate at which the vehicle accelerates, is limited.

Global climate change and an increasing energy demand are driving the scientific community to further advance internal combustion engine technology. Invented by Sr. Henry Ricardo in 1918 the torch ignition system was able to significantly decrease engine’s fuel consumption and emission levels. Since the late 70s, soon after the Compound Vortex Controlled Combustion (CVCC) created by Honda, the torch ignition system R&D almost ceased due to the issues encountered by very complex and costly mechanic control systems that time. This work presents a stratified torch ignition prototype endowed with a sophisticated electronic control systems and components such as electro-injectors from direct injection systems placed on the pre-combustion chamber. The torch ignition prototype was tested and its performance are presented and compared with the baseline engine, which was used as a workhorse for the prototype engine construction.

The limited thermal efficiency in internal combustion engines provides a partial transformation of fuel energy in net power. The heat lost through the exhaust gases represent a significant portion of energy looses. The Seebeck Effect is the direct conversion of temperature differences between two dissimilar metals or semiconductors into electrical voltage. The present study demonstrates the application of thermoelectric generators technology in Baja SAE vehicles to recovery exhaust heat looses, using thermal energy converter devices. The electrical energy produced in Seebeck Effect Cells, assembly in engine exhaust manifold, is conditioned and applied in vehicle batteries and supply energy consumption during vehicle operation. This action could increase the vehicle energy efficiency by the recovery the thermal energy dissipated. This extra power supply makes possible the reduction of on board batteries charge capacity and also recharges them without external power sources.