Experimental and modelling analysis of the heat transfer with hybrid channeling of Al-Al and Al-Cu systems

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Insinööritieteiden korkeakoulu | Master's thesis
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Master's Programme in Mechanical Engineering (MEC)
The Hybrid channeling (HC), is a novel manufacturing solution enabling simultaneous welding and channeling of multiple metal components from similar or dissimilar materials and geometries. During HC process, a weld and a sub-surface channel are created in one action, that makes it the only known technique capable of such performance. HC technique reveals new component manufacturing possibilities by optimizing physical and chemical performance, for high demanding applications where continuous channels along a free path are desired. Therefore, it can be said that the HC technique combines the best of Friction Stir Channeling and Friction Stir Welding processes, in a distinct single processing action with its own challenges, benefits and field of application. The scope of this investigation is to evaluate via experimental analysis and computational simulation the thermal performance of the components produced by HC. The work plan was set to assess the effect of the distinguishable features of the HC, namely the physical continuity between the welded materials; and the non-uniform, non-directional and multi-dimensional irregular surfaces inside the channel that promote the early onset of turbulent flow. In order to understand the effects of the HC features, the thermal performance was evaluated as a comparison with same length channel on Al-Al and Al-Cu material combinations produced by HC and other conventional manufacturing techniques, i.e. via milling of the channels and bolted joints. The results received from the experimental work with air and water cooling media showed that the removal of the heat is faster for HC samples especially with the water flow. The tests performed with the air flow inside the channel showed only small differences between the components produced by HC technique and conventional techniques because the long extension of the channels resulted in the saturation of the heat extraction. The experimental test results were used to calibrate Computational Fluid Dynamics (CFD) models in CFD-Ace+ software. The CFD approach is now ready to be further explored.
Vilaça, Pedro
Thesis advisor
Sorger, Gonçalo
hybrid channeling, experimental thermal analysis, computational fluid dynamics, friction stir channeling, friction stir welding
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