Multidisciplinary design and manufacturing of a Tesla pump prototype

Abstract

To widen the range of hydraulic efficiencies of boundary layer pumps, a full design methodology has been proposed in order to identify critical issues for their performance and manufacturing. The methodology integrated a 2D numerical code, CFD and FEM analyses, coupled with manufacturing assessments as feedback mechanism. Considering budget constraints and in-house machining capabilities, a quick first prototype was produced. Analyses of the design are pointing out that the volute design initially chosen will not help to achieve an increase in the overall efficiency. The curves of head achieved with 2D and CFD are in agreement, but the latter determines the losses with larger accuracy, thus achieving lower values of head. The 2D model shows limits in the determination of the efficiency, effectively corrected by the CFD analysis. Critical parameters as disc thickness and gap between discs will require a more sophisticated assembly process and materials outsource. The proposed methodology could be used as a reference for the design and performance evaluation of this kind of turbomachinery in the future. The procedure lead to a prototype design, whose optimal efficiency slightly lower than 30 % was achieved at 5000 rpm with 0.3 mm disks gap.