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Mathematical And Numerical Modeling Of Swirling Flow In Francis Turbine Draft Tube Cone
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Scientific Bulletin of the “Politehnica” University of Timisoara, Transactions on Mechanics, Tom 50(64), pp. 1-16
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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.
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| ISSN 1224-6077 |
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2005
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| Francis turbine, draft tube cone, swirling flow, unsteady 3D simulation, steady axisymmetric flow model. |
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No file uploaded
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SUSAN-RESIGA Romeo
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AVELLAN Francois
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CIOCAN Gabriel Dan
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MUNTEAN Sebastian
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National Journal Article
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http://mh.mec.upt.ro/accord-fluid/workshop2005/docs/01_Resiga1.pdf
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Numerical Simulation and Parallel Computing Laboratory
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| Institution: |
UPT
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