A New Generation of Tools for Accurate Thermo-Mechanical Finite Element Analyses of Engine Components

A set of methods is described to calculate boundary conditions for thermal and mechanical finite element (FE) analyses and to assess and present the results of those analyses in a clear and understandable way. The approach utilizes a combination of engine simulation programs and an empirical database of engine measurements developed over many years. The methodology relies on the use of specialized FE pre- and post-processors dedicated to the analyses of engine components.

Gas-side thermal boundary conditions for combustion chamber components are calculated using an engine simulation code for standalone FE analyses or for FE analyses directly coupled to the engine simulation code itself. Coolant side boundary conditions are calculated using multidimensional flow analysis (computational fluid dynamics). Boundary conditions in intake and exhaust manifolds are calculated using a one-dimensional gas dynamics code.

Thermo-mechanical analysis results are assessed and presented using dedicated post-processing tools to determine the effects of temperature on local material strength, and to calculate distributions of safety factor against ultimate strength, yield strength and fatigue strength. New methods of results presentation are described for the analysis of cylinder bore distortion, piston-liner interaction, cylinder liner cavitation and valve seat wear.