Modelo ar-combustível de tempo finito de adição de calor de motores Otto

Abstract

The air standard internal combustion engines study assumes that several thermodynamic properties for the work fluid are constant, and also admits this fluid is pure air or ideal gases. Clearly, the error from using this kind of hypotheses for the work model prevents Otto cycle combustion engines projects. Some characteristics that can be rethought for this Otto cycle operation models are fuel and air mixtures as a work fluid and a non isochoric heat addition to the system, knowing that this methods were developed in the references (BRUNETTI, 2012) and (NAAKTGEBOREN, 2017), respectively. For the combustion model and possible fuels, stoichiometric relations can be solved to find the products, from where not only the thermodynamic properties can be calculated for the desired instant, but also the heat addition amount to the system. The engine dimensions and other operating parameters become relevant in the non isochoric heat addition model, since the combustion no longer happens instantly, as the air standard cycle previously consider. The following work aims to develop a new model capable of assume a mixture of air and fuel for the work fluid, while using the finite time heat addition model solution procedure for the problem.