Simulação e validação experimental de um motor sobrealimentado operando a etanol

Abstract

Currently the development of internal combustion engines is focused on reducing greenhouse gas and polluting gases emissions in order to meet increasingly strict limits on emission control and energetic efficiency. One of the most applied tools for the engine development in an attempt to meet these requirements is the computer simulation, in which main engine geometric characteristics are virtually modeled to predict engine behavior when boundary conditions are varied. In order to have a reliable engine modeling, a validation process with experimental data needs to be performed. In this context, the objective of this work was to validate a computational model of the Volkswagen AP 1800 engine operating with ethanol. The operating conditions validated was at full load and at engine speeds of 4000 to 6000 rpm with a 500 rpm step in the GT-POWER software. This engine is widely used at laboratory experiments due to its low cost, constructive simplicity, durability and robustness. Initially, physical measurements of the engine were performed, head discharge coefficients were obtained on a flow test bench, valve lift was measured, and then test routines were specified on a dynamometric bench. From the experimental data, the modeling and validation process was started according to the GT-SUITE validation manual. Among the results obtained in the modeling the GT-SUITE manual recommends comparing with experimental data mainly the following parameters: air mass flow rate, fuel mass flow rate, lambda and the IMEP. The measured-simulated comparison of these parameters showed errors of less than 5%. Thus, from the results obtained it can be concluded that the computational model is validated and safe to carry out projects and analyze the influence of the boundary conditions on the engine.