Thermal and Mechanical Loading in the Combustion Bowl Region of Light Vehicle Diesel AlSiCuNiMg Pistons; Reviewed with Emphasis on Advanced Finite Element Analysis and Instrumented Engine Testing Techniques. 2012-01-1330

The continued rise in specific power output and thermal loading characteristics of the modern automotive diesel engine provides piston engineers and scientists with the challenge of continually improving their knowledge and understanding of thermomechanical loading and durability factors. The capacity to predict thermomechanical fatigue (TMF) effects with confidence at a pre-engineering stage will improve the technology selection and component design processes leading to a more efficient development phase.

This paper reviews how the use of advanced instrumented engine testing and finite element modeling (FEM) techniques are helping engineers improve their understanding of transient thermal load regimes in automotive AlSiCuNiMg pistons. The investigations offer insightful observation of transient measured piston temperatures in the high and low frequency operating regimes for two diesel engine platforms. The initial section of the paper provides an introduction to diesel piston combustion bowl loading and the simulation techniques presently in use and being developed to enhance the capability of time dependent thermomechanical deformation and fatigue modeling. Concluding this section is a similar synopsis of key issues relevant to the characterisation and testing of ‘engine-like’ loading for AlSiCuNiMg piston alloys.