Predesign Model for Intake Manifolds in Internal Combustion Engines

An original calculation model based on the acoustic-wave theory is presented in this paper, capable of calculating the overall dimensions of an optimum intake manifold, with the aim of improving the gas exchange process in the engine. Some parameters depicting the dynamic interaction between the engine and the manifold are defined, which also allows the assessment of the manifold quality. By employing these parameters, the model can be applied in two complementary modes: the acoustic analysis of an existing manifold and the synthesis of an optimum geometry according to the design requirements and restrictions. The model results are assessed by the test on engine of some prototype intake manifolds, designed following the guidelines of the model.