Use this URL to cite or link to this record in EThOS:
Title: Computational investigation of flow regimes and performance characteristics of a pump operating as a turbine
Author: Rodrigues, Arnaldo
ISNI:       0000 0001 3530 6964
Awarding Body: Nottingham Trent University
Current Institution: Nottingham Trent University
Date of Award: 2006
Availability of Full Text:
Access from EThOS:
Access from Institution:
This project deals with the investigation of the physical significance of the internal hydraulics of a pump operating as a turbine through the means of computational fluid dynamics. The pump as turbine is a new application area for CFD with very limited studies published. A commercial code is used to enable the modelling of the pump as turbine and thorough discretization is carried out to understand the most suitable solution parameters for the modelling. The 'Hydraulic Loss' methodology is developed to analyse seven individual zones within the geometry of the pump as turbine with the aim of understanding two major unattended problems. The first concerns methods for translating actual geometry into a mesh which is solvable yet still accurate. Four interface models between the volute and impeller are investigated and compared against already available experimental data. The most accurate interface is the geometrical model that closely represents the actual geometry, whilst the least accurate is the less complex geometrical interface model. CFD has shown that accurate PAT geometry representation is necessary to accurately predict the performance characteristics. The second is with respect to the improvement of the performance characteristics of the pump as turbine through geometry modification. Four geometrical modification stages are investigated and three are compared to the available experimental data. CFD has shown good agreement with the experimental performance characteristics and has been able to detect the effects on losses and performance due to the different modifications. The modifications have shown that impeller rounding, back-shroud sharpening, and casing rings have improved the performance of the pumps as turbine whilst the impeller eye enlargement has improvement in performance in the part load region only. The computational method has allowed for practical guidelines on the selection of pumps for turbine operation. Recommendations are made for further work in the area of PATs.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available