Abstract

This study investigates the fluid flow through the runner of an exceptionally low specific speed Francis’ turbine using computational fluid dynamics (CFD) to predict some performance characteristic of the runner, and to determine the effect of cavitation on the flow features within the turbine. It employs FLUENT CFD codes for the analysis. The study was carried out under steady conditions in two- dimensional analysis, primarily using the RNG k-ε turbulence model. It is mainly on single phase analysis; however a single case of two-phase cavitation modeling was performed in order to evaluate cavitation effects. The hydraulic losses were much dependent on the inlet flow velocity and less dependent on the rotational speed. Cavitation occurred throughout the flow domain and this led to non-physical negative pressure predictions for the single phase analysis. For a fixed discharge, cavitation had significant effect on the prediction of the torque and hence the runner efficiency obtained from the CFD analysis. It causes a significant reduction of the runner efficiency by increasing the hydraulic losses and should be considered in the analysis of the flow features within a runner which is likely to experiences cavitation in order to overcome some of the shortcomings of the single phase predictions.

School

School of Sciences and Engineering

Department

Mechanical Engineering Department

Degree Name

MS in Mechanical Engineering

Date of Award

Spring 6-1-2008

Online Submission Date

3-17-2008

First Advisor

Serag El Din, Amr

Committee Member 1

Ashraf Sabry

Committee Member 2

Lamyaa El-Gabry

Committee Member 3

Mustapha Rizk

Document Type

Thesis

Extent

107 p.

Rights

The author retains all rights with regard to copyright.

The American University in Cairo grants authors of theses and dissertations a maximum embargo period of two years from the date of submission, upon request. After the embargo elapses, these documents are made available publicly. If you are the author of this thesis or dissertation, and would like to request an exceptional extension of the embargo period, please write to thesisadmin@aucegypt.edu.

IRB

Not necessary for this item

Creative Commons License

Creative Commons Attribution 4.0 International License
This work is licensed under a Creative Commons Attribution 4.0 International License.

Share

COinS