The Application of Steady-Flow Loss Correlations to Intake Manifold Design

Application of steady-flow correlations to characterize flow losses in complex piping systems is well established for non-transient fluid transport engineering. As a result, the literature contains numerous correlations relating flow (or pressure) losses to the piping system geometry. The present study applies these correlations to an intake manifold of a four cylinder engine to identify regions in the manifold that contribute most significantly to the system flow loss; results showed that the primary runner entrances accounted for over half of the total system loss. With this finding, four manifolds were designed and tested on a steady-flow bench and on an engine. Reduced flow losses resulted in improved peak engine performance at the expense of low speed volumetric efficiency. Primary runner pressures at peak performance conditions were analyzed in both the time and frequency domain.