Numerical analysis of a laboratory centrifugal pump for the training of graduate engineers

The up-to-date design of turbomachinery involves the use of three dimensional computational fluid dynamic analyses to match the challenge of the ever increasing speed of the product development. Recently, these analyses applied to turbomachinery, which in past years were confined to special fields, have became widespread in many industrial applications. Hence, besides the teachings of traditional methods for turbomachinery design, an important part of modern engineering education is to produce graduates with advanced skills in Computational Fluid Dynamics (CFD) techniques applied to turbomachinery design . Moreover, at this time, these skills should either match the needs of research laboratories or be compatible with industrial needs, since three dimensional numerical calculation is becoming to be seen as a feasible tool also in ordinary applications. For these reasons, CFD courses for the training of graduated and undergraduated students have been grown. To match the requirements of an as complete as possible knowledge of the main features involved in a numerical analysis, a number of different issues should be addressed and properly treated within the course. In this paper, the methodology followed and the work carried out by the students of the course of the Fluid Dynamic Design of Turbomachinery held at the University of Ferrara is presented. In particular, three levels of investigation are taken into consideration and presented: (i) the focus in the fundamentals which should be addressed to achieve a basic knowledge of a design process based on numerical simulation; (ii) the extension to an higher level of in-depth analyses of the specific models which could be used in every phase of a numerical simulation; (iii) the insight into the specificity of the main thermodynamic and fluid dynamic characteristics of turbomachinery. To do this, the numerical analysis of a simple but exhaustive geometry (a laboratory centrifugal pump for which extensive information are available in literature) has been carried out and the results obtained are addressed. In particular, special emphasis is devoted to the comparison among the numerical models which can be chosen throughout the simulations of turbomachinery (turbulence models, rotor/stator interface, etc.) and the analysis of the most important fluid dynamic phenomena inside a centrifugal pump