Mesh technique for swirl induced flow

Abstract

In engineering, heat exchangers play a key role in many processes. The efficiency of heat exchangers can yet be improved, for example, by swirling the flow. Swirl flow improves the heat exchange and slows down the rate of precipation. In this thesis, the objective is to investigate and find a good setup for fixed guidance blades that swirl the flow. A good setup should result in low decay of the swirl intensity so the swirl would persist in the flow for as long as possible. There have been few relevant studies on the topic. None of them examined different setups of guidance blades with the aim to find a practical solution. In this study, the calculations aredone with computational fluid dynamic models. Blades are inserted in the mesh as straight planes and the mesh is twisted to obtain the desired layout. Overall, nine different setups of swirlers are set up and calculated. The focus is on the pitch of the blades and their form. The results showed that by minimizing the angular flow at the walls, the decay of the swirl intensity could be reduced considerably. The best setup has the highest pitch close to the center while decreasing with growing radius. The effect of thenumber of blades was also investigated. The results showed that increasing the number of blades did not lower the swirl decay. This study offers good insight on an efficient setup and use of guidance blades in a swirl flow. This study will be an essential starting point in further studies on the subject. Such as assessing what swirling flow blades best fit in turbulent flow.