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Master Thesis
Department of Hydraulic and
Environmental Engineering
Physical Modelling of Surge
Tank Throttling
By Robert Landskaug
Supervisor:
Professor Leif Lia /
PhD candidate Kaspar Vereide
Background
Results from LVTrans with different throttle loss coefficients
The air cushion surge chamber in the
physical model
Surge tanks are applied in hydropower plants for dampening of water hammer, and to
ensure regulation stability of the power plant. The surge tank may be constructed with a
throttle, which introduces a singular loss when water is flowing into or out of the surge
tank. Especially for hydropower pumped storage plants the implementation of a throttle is
beneficial due to the massive hydraulic transients occurring in such systems.
Design of such throttles is a complex process, and the throttles are designed individually
for each power plant. In order to gain further understanding of the throttle effect, and to
improve the design of such structures, research is required.
In this master thesis a surge tank throttle will be design and tested in the physical model
of Torpa hydropower plant in the laboratory. Then STAR CCM+ will be used to simulate the
throttle numerical, and the results will be compared. The 1D simulation software LVTrans will
be used to find the best local head loss, which will be used to design the throttle.