Design of flow guiding parts through CFD topology optimisation

Abstract: Scania works continuously to develop internal combustion engines and after treatment systems which can achieve low pollutant emissions and high efficiency. A major principal that Scania adopted for this goal is the Simulation Driven Development (SDD) process. Here computer aided simulations aid to develop designs and improve characteristics all the while reducing the iterative prototyping and testing process. Currently, parametric modelling and Design of Experiments (DoE) is a proven and major mode of exploring designs within the various stakeholder fields of development; namely structural, fluid mechanics and acoustics.  Topology optimisation in fluid flow is a new field which promises quick exploration of design spaces. The result of topology optimisation are unintuitive designs that could serve as baseline designs which can further reduce the design process. The objective of the thesis was to explore topology optimisation and investigate a way to incorporate topology optimisation in the design process at Scania CV AB. For this task Tosca Fluid by Dassault Systèmes was chosen for its optimisation capabilities, which uses back-flow as the criteria of optimisation. The case study was conducted based on the MTX diesel one box inlet end-plate which was used as reference. The dimensional constraints of the reference product were used to model and utilise the developed workflow. Since this task involved the use of substrates for exhaust gas filtration, it was imperative to explore uniformity of flow over the substrate as an additional optimisation criterion. The project studied modelling design spaces to satisfy the design criteria and the shortcoming the software currently poses have been documented in this report. The report also mentions the tasks involved in setting up simulation cases to work well with Tosca Fluid. In the current stage of the thesis work it was not possible to incorporate uniformity as an additional criterion and hence fails in using Tosca Fluid to optimise topology for turn volumes involving the use of substrates.