Desarrollo y validación de un modelo cero dimensional de dos zonas para el análisis de la combustión en motores de encendido provocado

Abstract

The growth of the automotive fleet in cities and the imminent depletion of traditional hydrocarbon deposits mean that research in the field of internal combustion engines focuses on generating strategies and developing technologies that allow a reduction in fuel consumption and pollutants emissions. The use of numerical models for simulation is an important tool for both researchers and designers as they allow to approach the performance of the engines under certain operating conditions without incurring in the expense involved in experimental studies and allow analyzing multiple phenomena that occur during combustion that are not easily evaluable from experimental measurements. In this study, a zero-dimensional two zones model which separates the combustion chamber into burned and unburned gases was developed seeking to study the combustion process in ignition engines using gaseous renewable fuel (biogas), using the Law of Wiebe and the chemical equilibrium to simulate the combustion process and the Woschni's semi-empirical correlation for heat transfer. The model is calibrated with information obtained from a high compression ratio (15.5: 1) engine of the combustion and thermal machines laboratory of the University of Antioquia. The main variables of combustion and engine performance (heat release rate, maximum pressure, indicated work, among others) were compared with the results of the model, as well as the emissions generated from CO and NO. There are low errors between the experimental values predicted by the model, with errors less than 10% for the main variables, except for the indicated work, with errors of 27%, and errors between 18% and 49% for the generated emissions, obtaining the highest errors as the degree of load of the motor increases.