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Three-dimensional steady compressible turbulent flow fields in two types of inlet manifold are numerically simulated using the arbitrary Lagrangian - Eulerian (ALE) method. The effects of turbulence are represented by k-ɛ 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 diesel engine inlet manifold have great effects on the engine discharge efficiency and CFD is a powerful tool in intake manifold design.

A Failure Mode, Effect and Criticality Analysis (FMECA) is a methodology used to define, identify and eliminate known and or potential failures in order to enhance the product's reliability and quality. The Criticality Analysis plays an important role in FMECA. A method defines the failures' priority to find the most risk area. Traditionally, in automobile industry, the criticality assessment is based on the severity (S), frequency of occurrence (O), detection (D) of an item failure. The priority of the problems is articulated via the Risk Priority Number (RPN). This number is a product of the occurrence, severity and detection, i.e., the method assumes that the occurrence, severity and detection have same importance. Additionally, the component and system can only be in either of the two states: functioning or failed. However, it does not represent reality. In fact, failure mode is of fuzzy conception.