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Water hammer 2 phase analysis hydraulic system with a Kaplan turbine

 
: Dudlik, A.; Koutnik, J.

:
Postprint urn:nbn:de:0011-n-1206789 (1.0 MByte PDF)
MD5 Fingerprint: 86d312c304aa1023c03fbd036f276d9e
Created on: 1.4.2010


Rudolf, P. ; International Association for Hydraulic Research -IAHR-; Brno University of Technology -BUT-, Brünn:
3rd IAHR International Meeting of the WorkGroup on Cavitation and Dynamic Problems in Hydraulic Machinery and Systems 2009. Proceedings : Brno, Czech Republic, October 14 - 16, 2009
Brno: Brno University of Technology, 2009
ISBN: 978-80-214-3947-4
ISBN: 80-214-3947-5
pp.613-624
International Meeting of the Workgroup on Cavitation and Dynamic Problems in Hydraulic Machinery and Systems (IAHRWG) <3, 2009, Brno>
English
Conference Paper, Electronic Publication
Fraunhofer UMSICHT Oberhausen ()
pipeline; Kaplan turbine; pressure surge; cavitation hammer; measurement; Rohrleitung; Kaplanturbine; Druckstoß; Kavitationsschlag; Messung

Abstract
This investigation has been carried out for a case of sudden closing of a Kaplan turbine from a runaway operation. This work has been done at Fraunhofer UMSICHT, supported by VH.
The runaway case has been selected as it is known that the discharge through a Kaplan turbine increases with its speed, and may reach up to twice the value of nominal discharge.
The simulation model consists of:
- penstock
- Kaplan turbine (modelled with a valve characteristic)
- draft tube
All hydraulic pipe elements were considered as 1 dimensional, 2-phase flow allowing estimation of cavitating volume size.
The valve characteristics cannot be charged during the simulation (as a function of turbine actual speed), therefore the Q-Delta-H characteristic had to be taken from VH 1D, 1 phase analysis for a given closing law. The turbine characteristic used for VH analysis has not considered any cavitation effect.
Results of the analysis are time records of pressures at the spiral case and draft tube as well as the axial force acting on the turbine head cover. In addition, the cavitating volume size is evaluated.
The 1st step was 1phase analysis and validation with VH results.

: http://publica.fraunhofer.de/documents/N-120678.html