THERMODYNAMIC MODELING OF A PISTONS ENGINE: CALCULATION OF THE NOX EMISSIONS

The internal combustion engines are under development remarkable these last decades, but they represent, currently, a very important source of polluting gas emissions. The nitrogen oxides (NOx) form part of these polluting emissions, and have a harmful effect on human health, as well as the environment. Considering the complexity of the process of formation of the latter, many numerical simulations were developed, to work out a model of calculation close to the reality, which is so complex to describe by the theory. Our work, allows the calculation of the nitrogen oxide rate (NO) in exhaust gases, starting from the developed equations of the chemical kinetics, while being based on the thermal mechanism of Zeldovich. To carry out this calculation, a simulation of the thermodynamic cycle was necessary. A model of combustion at two zones (burned and unburned) was adopted. Simulation is carried out for a spark-ignition-engine (gasoline), and the results obtained, were compared with other simulations as well as with results of measurement from the literature.