This study topology (or rather shape) optimization of extrusion dies were examined (link). Two aspects were optimized, reduction of dead zones and flow speed equalization. Interestingly the dead zone reduction was done by hand, in a systematic way. Flow speed equalization was carried by an evolutionary algorithm, which introduces random intrusions to the flow. The best results were optimized when they are used consecutively at each optimization step.
It is stated that extrusion die design is expert knowledge based, and optimization or simulation software are not widely used at the moment.
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