Effect of a fastener hole design of inlet flanges on the durability of the exhaust manifold for a turbo-diesel engine

Abstract

Abstract

A clever design of fastener hole, which allows sliding behaviour, is investigated so as to understand the effect on the durability of the exhaust manifold for a turbo-diesel engine. Finite element analysis and experiments are performed to investigate the thermal deformation of the exhaust manifold with the fastener hole design. Temperature-dependent material properties of the exhaust manifold and sliding behaviour between the manifold and cylinder head are considered for the finite element model. A considerable amount of sliding between the manifold and cylinder head owing to the permanent deformation of the exhaust manifold are expected from the analysis. Experiments followed to verify results of the analysis. The plastic strain range, which is often used as the criterion for crack initiation, was estimated and compared with that of the exhaust manifold with a conventional fastener hole design, which does not allow sliding between the manifold and the cylinder head. Results revealed that a fastener hole design that allows sliding of the exhaust manifold, increases the durability of the exhaust manifold for the turbo-diesel engine.