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Biofuels for internal combustion engines have been explored worldwide to reduce fossil fuel usage and mitigate greenhouse gas emissions. Additionally, increased spark ignition (SI) engine part load efficiency has been demanded by recent emission legislation for the same purposes. Considering theses aspects, this study investigates the use of non-conventional valve timing strategies in a 0.35 L four valve single cylinder test engine operating with anhydrous ethanol. The engine was equipped with a fully variable valve train system enabling independent valve timing and lift control. Conventional spark ignition operation with throttle load control (tSI) was tested as baseline. A second valve strategy using dethrottling via early intake valve closure (EIVC) was tested to access the possible pumping loss reduction. Two other strategies, negative valve overlap (NVO) and exhaust rebreathing (ER), were investigated as hot residual gas trapping strategies using EIVC as dethrottling technique.

The ever increasing pressure for more efficient engines, with lower production cost and time has led to the development of advanced simulation tools. Likewise, the experimental development of combustion systems has benefited from computational tools while reducing the necessary experimental time. This paper describes the analysis of combustion performance of a Diesel engine normally used on generator sets. A detailed heat release analysis is performed through one-dimensional simulation software and experimental results, enabling a comprehensive description of combustion parameters of the engine through a simplified study. Brake and indicated values were obtained and analyzed to point out efficiency maps and show the effectiveness of the simulation tool in engine and combustion systems development.

Due to the ever growing environmental concern regarding global warming and CO₂ emissions, the use of renewable fuels has become increasingly important. Thus, substituting fossil fuels such as diesel by ethanol from sugar cane can be a good alternative. There are, however, several ways of performing it. One of the simplest methods is to use fumigated ethanol with an electronic fuel injection system, operating in dual fuel mode with the original diesel injection, substituting part of the fuel by ethanol. This paper demonstrates the effects of using fumigated ethanol on performance of a standard power generation 4-cylinder turbocharged diesel engine. The research combines simulation results with experimental validation. Initially, a one-dimensional computational model of the original engine running solely on diesel was created and validated for several power levels.