Unsteady Filling and Draining Cycles in Designing the Upper Chamber of the Surge Tank Limberg II

The pump storage hydro power plant Limberg II of the hydro power scheme Glockner-Kaprun, Austria, will generate power using the difference in height between two reservoirs. A two-chamber surge tank will be built between the pressure tunnel and the pressure shaft. The design of this surge tank was checked by a hydraulic model test with a scale o 1:30. This article focuses on the unsteady filling and draining cycles which have to be considered in the design of the upper chamber of the surge tank.