The Q1D flow model, combined with the reduced-order model of the cylinder charge, is able to capture the dominant intake and exhaust fluid mechanics and produces results that compare well with measurement. The results indicate that the isentropic-based model neglects important fluid mechanics and returns inaccurate results.
Both include friction and cylinder loss models so that the predicted performance values can be compared to measurements. Both models employ the same heat release and reduced-order modeling of the cylinder charge. The second model predicts the intake and exhaust processes using a compressible, time-accurate, Quasi-One-Dimensional (Q1D) approach. The first model predicts the intake and exhaust processes using isentropic flow equations augmented by discharge coefficients. In this thesis, two models of four-stroke, internal combustion engines are created and compared.
