Fluid dynamic design and optimization of a double entry fan driven by tractor power take off for mist sprayer applications

In this paper, the fluid dynamic design of a double entry fan driven by tractor power take off for mist sprayer applications is presented. The design is carried out by means of an integrated 1D/3D numerical procedure based on the use of CFD simulations. Moreover, an experimental campaign performed to characterize the existent fans is presented. The collected data are elaborated in order to fix a design starting point and to validate the CFD procedure. The CFD simulations are then used either at the preliminary design stage to choose among competitive one- or two-dimensional geometries and then to test the generated three-dimensional geometries. The results show how the different design choices could impact on the performance parameters and, finally, how the analysis of the various alternatives allows the determination of the overall geometry of a complete and performing centrifugal fan. Finally, the double entry fan has been prototyped and tested. The test confirmed that the designed fan met the manufacture requests in terms of efficiency, maximum flow rate and head and noise level.