Turbocharger service interval predictions

Working in a cooperation project with the Fraunhofer Institute for Mechanics of Materials (IWM), the BAM and the IWM have succeeded in developing a computational model which could help operators get better at maintenance planning.

“The computational model helps us to be more accurate at predicting the service life of aluminium radial compressor wheels, even when they are subject to heavy operational demands,” said Professor Ing Birgit Skrotzki, Head of the Division of Experimental and Model Based Mechanical Behaviour of Materials,

“[This will] allow manufacturers and users to calculate how long the engine will run reliably – whether in city traffic or at sea.”

Service life

Maintenance intervals for exhaust gas turbochargers are dictated by various factors including the aluminium radial compressor wheels.

The problem is that the temperature rises as the air is compressed, causing the material to age and lose its original strength. It has not been possible up until now to describe this ageing process and therefore to predict the service life of the component with sufficient accuracy.

During the research, scientists at the BAM observed an aluminium alloy during the ageing process. The material was cured in the manufacturing process at 195 degrees Celsius to attain its optimum strength. It was then aged using air compression.

The data obtained on the microstructure were taken as a basis for an extended computational model which considers the loss of material strength.