variavel0=<b>Guilherme Pianovski</b> - guilherme@cefetpr.br Centro Federal de Educação Tecnológica do Paraná C
<b>José Antonio Velásquez</b> - velasqz@rla01.pucpr.br Pontifícia Universidade Católica do Paraná PUCPR
<b>Abstract.</b> It becomes evident from economical and environmental reason the need for developing substitutes to petroleum derived fuels, in particular, to diesel fuel. Because they are sustainable and bionomic, esters of vegetable oil (biodiesel) are distinguished among the possible alternatives for this substitution. Combustion characteristics of several blends of biodiesel and diesel fuel were studied in this work. This study was carried out admitting that a homogeneous mixture of combustion gases in equilibrium (ideal gases) forms the engine working fluid. Additionally, it was considered that injected into combustion chamber fuel vaporizes and burns out instantaneously, according to single zone combustion model. Experimentally obtained indicating pressure diagrams were used to evaluate combustion heat release rate of a turbocharged diesel engine. For this evaluation, chromatographic data of a sample of biodiesel, produced from soybean oil and hydrated ethanol, were used in order to obtain empirical formulae of studied blends of biodiesel and diesel fuel. Calculated combustion heat release rate curves are presented and analyzed, emphasizing the physical phenomena that influence these curves.
<b>Keywords.</b> Diesel engines, Combustion, Heat release rate, Biodiesel, Alternative fuels.