A re-design process of an industrial centrifugal fan through CFD and rapid prototyping

Abstract

Due to the ecological-green transition, it is fundamental to reduce the energy consumption of turbomachines in many fields. In particular, manufacturers of industrial fans are subjected to EU regulation N.327/2011, which indicates the limit for the absorbed power of this kind of machine. New design techniques allow to increase the overall efficiency satisfying the customer’s performance request. Recently, in order to reduce time to market, the manufacturers are very interested in using plastic materials in place of metal in the prototyping phase because they have higher formability, lower costs, and realization time. The aim of the authors is to present the re-design process of a commercial industrial centrifugal fan. The main goal was to change the shape and the number of the blades reducing the separation along the blade-to-blade channel, limiting the leakage flow, and increasing efficiency. Several modifications to the initial geometry were proposed and analyzed through numerical simulations. Three designs were then produced via a rapid prototyping process in plastic material and tested in a standardized rig. Moreover, a comparison between the experimental performances of the actual impeller made in metal sheets and the plastic one will be evaluated in order to view the effects of different roughness and deflation that characterize a plastic component realized using a 3D printing technique.