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The soot emission is one of the main limiting factors in the Diesel engine performance, due to the heat losses caused during its formation. Studies show that the formation of this product can be reduced by adding oxygenated fuels to replace part of fossil fuels. There is a growing demand for computational models of engines powered by renewable fuels, capable of predicting operational characteristics in different conditions. The objective of this work is to determine, by using computational fluid dynamics (CFD) model, the effects of different percentages of biodiesel on the spatial distributions of soot inside the combustion chamber. Performance and emissions, as well as spatial distributions of soot and temperature were evaluated simulating cases with 8%, 10%, 13%, 15%, 50%, and 100% for mixtures of biodiesel.

The injector driving strategy influences both the performance and the emission produced by internal combustion engines. The injector driving strategy is the intellectual property of the automotive industry; its disclosure is restricted to the automaker and the injection system supplier. The objective of this paper is to present a drive circuit for common rail diesel injectors. The circuit design is based on transient simulations using an equivalent virtual circuit, to be used on a test bench for injection strategies. The simulated electric current curve has been compared with experimental measurement under the same conditions in the projected circuit, the errors has remained at approximately 6%.

This paper analyses the effects of the application of the exhaust gas recirculation (EGR) technique in a stationary, single cylinder engine aiming to reduce the emissions of nitrogen oxides (NOx). The engine was operated with diesel oil containing 8% biodiesel (B8) for different load and EGR rates. The engine emissions of carbon monoxide (CO), carbon dioxide (CO2) and nitric oxide (NO) operating without the EGR system were compared with the operation with EGR rates of 15% and 25%. The results revealed that the increase in the EGR rate increased the exhaust gas temperature, the engine specific fuel consumption and the CO and CO2 emissions, but with reduction of up to 72% of NO emissions, when using 25% of EGR rate.

This paper presents the physical adjustments and the incorporation of a control system to injection, ignition and throttle valve parameters for operation of a diesel engine with 100% hydrous ethanol. The control system of the aforementioned parameters integrates three dependent subsystems. The control systems of the throttle valve opening, fuel injection and ignition timings have the purpose to reduce cylinder pressure, control engine speed and the combustion process. The signals generated depend on engine speed and knock sensors, which are operated by microcontrollers programmed in Assembly and C language. The measured parameters during engine operation are relative humidity, temperature in different engine locations, fuel consumption and intake air mass flow rate. The data collected are monitored by a software developed in LabVIEW platform. The software also controls the load applied at each engine operating condition.

This study presents the effects of fuel blends containing 5%, 10%, 15% and 20% of anhydrous ethanol in diesel oil with 20% of biodiesel (B20) on performance, emissions and combustion characteristics of a diesel engine. The engine was tested with its original configuration and in the lower brake specific consumption region, at 1800 RPM. The results showed that in-cylinder peak pressure and heat release rate increased with the use of ethanol. The use of ethanol increased ignition delay and decreased exhaust gas temperature. Brake specific fuel consumption increased with ethanol addition, and fuel conversion efficiency was not affected. Increasing ethanol content in the fuel caused decreased carbon dioxide (CO2), carbon monoxide (CO) and total hydrocarbons (THC) emissions.

This paper presents an investigation on fuel consumption of a diesel engine fuelled with blends of natural gas-diesel and hydrogen-diesel. Experiments have been carried out in a 50 kW, four-stroke, diesel engine. Natural gas and hydrogen have both been injected in the intake manifold, while diesel was directly injected in the combustion chamber. Blends of 25%, 50% and 75% of natural gas in diesel were tested, while the concentrations of hydrogen were 20%, 30% and 50%. No alteration in the diesel injection system has been made when the gaseous fuels were used. The results show that diesel consumption is reduced proportionally to the necessary air amount for stoichiometric burn of the gaseous fuels.