Browsing by Author "Fiaschi, Daniele"

Now showing 1 - 3 of 3
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    Design and optimization of a Tesla pump for ORC applications
    (Technical University of Munich, 2021-10-11) Anselmi Palma, Eduardo; Fiaschi, Daniele; Nicotra, Giovanni; Talluri, Lorenzo
    The Tesla pump is bladeless turbomachinery known for being more resistant to work with hard-to-pump fluids than conventional turbomachinery, thanks to its simple, robust mechanical design and its working principle (viscous forces). A 2D numerical model is developed and a design procedure of a Tesla pump working with several working fluids (water, R1233zd(E), R1234yf) is proposed. A complete design methodology is developed by evaluating the losses of each component and by introducing a rotor model. The main optimizing parameters of the pump are highlighted and assessed and validation of the model with available experimental results is carried out. A design procedure for a Tesla pump prototype is showed and its characteristic curves are obtained and discussed. The results achieved are similar to other experimental Tesla pumps, with a maximum achieved efficiency of 26.8%. The extension of the model to organic working fluids allowed to predict pump efficiencies higher than 50% for low mass flow rate conditions for both assessed fluids.
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    Mechanical design and manufacture of a boundary layer pump
    (EDP Sciences, 2023-08-25) Bufalari, Lapo; Anselmi Palma, Eduardo; Rinchi, Mirko; Howard, Kevin; Talluri, Lorenzo; Fiaschi, Daniele
    This paper describes the current efforts to develop and manufacture a first prototype for a boundary layer pump as a mean to assess future and more complex designs. Following an approach of “learning by doing”, a previous design was re-assessed from a mechanical/workshop point of view. Budget constraints and in-house manufacturing capabilities were taken into consideration to deliver a new design, suitable for quick production. Challenges such as disc holding, gap spacing, pump intake, discharge nozzles, and tolerances were addressed. Structural analysis has been conducted; where every single component has been modelled and sized accordingly to standard practices. As a support of structural analysis, FEM analysis was also performed with the aim of identifying, discussing, and fixing any potentially critical issues, particularly regarding the bolts holding together the discs into the power shaft. Finally, modal analysis was performed in order to test the dynamic response of the rotor: its critical frequencies would be far from the working range of the machine. This paper gives an overview of the critical issues to be taken into account during the mechanical design of boundary layer pump prototypes for different working fluids in the field of power generation and thermal management.
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    Multidisciplinary design and manufacturing of a Tesla pump prototype
    (Elsevier, 2024-07-29) Bakogianni, Agapi; Anselmi Palma, Eduardo; Rajendran, David John; Bufalari, L.; Talluri, L.; Ungar, P.; Fiaschi, Daniele
    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.