Structural analysis and topology optimisation of an aftercooler cover for weight reduction in off-highway engine application

It is endeavoured to gain design direction by use of computational topology optimisation methods on off-highway engines to improve fuel economy and costs to the service provider via weight reductions. Most published studies are focused on key functional components of an on-highway vehicle that are required for the engine or vehicle to function. However, this study aims to use topology optimisation methods on the off-highway Cummins Inc. QSK78 aftercooler cover to achieve an improved design that at least maintains the current product performance, while the weight of the component is reduced. Such analysis has not hitherto reported in the context of off-highway vehicles. The method involves using topology optimisation techniques based on the given objectives relating to strain energy and natural frequencies. The topology optimisation results are used to provide an informed direction for the design of an optimised 3D CAD model. FEA is used to investigate the structural response of both the baseline and optimised covers. The final optimised design shows an improvement even at worst case of generated stress results while a weight reduction of 6.5% is achieved. It was concluded that further improvements could be made in the optimised design considering limitations due to customer constraints.