Research Center for Engineering of
                Systems with Complex Fluids
Title: Mathematical And Numerical Modeling Of Swirling Flow In Francis Turbine Draft Tube Cone
Published In: Scientific Bulletin of the “Politehnica” University of Timisoara, Transactions on Mechanics, Tom 50(64), pp. 1-16
Description: ABSTRACT The paper is focused on the swirling flow in the hydraulic turbine draft tube, with the aim of understanding the flow physics as well as to develop simple and robust mathematical models useful for design/ optimization of hydraulic turbines. First, we define a model problem simple enough to capture the features of decelerated swirling flows. The inlet velocity conditions however correspond to actual measurements at a Francis turbine draft tube inlet. Second, we examine the three-dimensional unsteady flow dynamics using and Euler simulation, in order to identify the evolution of the self-induced unsteadiness of the flow. Third, a steady axisymmetric flow model is presented, together with the a finite element algorithm for solving the governing non-linear equation. It is shown that this simplified model captures accurately the velocity profile in the region where the full 3D flow is practically steady, while introducing a stagnation central region where the flow is highly unsteady. Although this simplified model does not capture the flowfield unsteady quantities, it provides a very useful extension for the quasi-three-dimensional flow modelling in the turbomachine such that the draft tube cone can be accounted for in the design and optimization procedure.
ISBN: 
ISSN:ISSN 1224-6077
DOI: 
Publication year: 2005
Keywords:Francis turbine, draft tube cone, swirling flow, unsteady 3D simulation, steady axisymmetric flow model.
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Authors: SUSAN-RESIGA Romeo , AVELLAN Francois , CIOCAN Gabriel Dan , MUNTEAN Sebastian ,
Type: National Journal Article
Link: http://mh.mec.upt.ro/accord-fluid/workshop2005/docs/01_Resiga1.pdf
Laboratory: Numerical Simulation and Parallel Computing Laboratory
Institution: UPT