Abstract
Three-dimensional steady compressible turbulent flow fields in two types of vehicle engine inlet manifold are numerically simulate d using the arbitrary Lagrangian - Eulerian (ALE) method. The effects of turbulence are represented by k-e turbulence model. Intake and outflow boundaries are pressure inflow and outflow. All calculations are performed under the same inflow/outflow boundary condition. Mass flow rates of all manifold exits are calculated and compared to evaluate the manifold designs. The results indicate that the structure types of a multi -cylinder vehicle engine inlet manifold have great effects on the engine discharge efficiency and CFD is a powerful tool in intake manifold design.