Abstract
In case of a massive failure in the penstock of a high-head power plant, pipe-break valves uncouple the nearly horizontal part from the endangered and also mainly strained section. In addition to the prime cost of such valves the operation can be a non-negligible expense factor. In case of the modernisation of an existing power plant the alternative use of a locale up-station (weir) can be an economic solution. The paper will present the concept in detail and summarise the first results of the scale model test. Therefore, a box with different obstacles is investigated. Under fully submerged conditions the local head loss is measured and in the transient case the change to free surface flow can be monitored. This ongoing work also includes 1D- (WANDA) and 3D-numerical simulations (ANSYS-CFX) and focuses on the transient behaviour.